Adding upstream version 0.12.0.

Signed-off-by: Daniel Baumann <daniel@debian.org>
2025-02-24 10:57:24 +01:00 · 2025-02-24 10:57:24 +01:00 · 148efc9122
commit 148efc9122
parent d887bee5ca
69 changed files with 12923 additions and 0 deletions
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@ -0,0 +1,15 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "pip" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "monthly"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@ -0,0 +1,47 @@
+name: Build and Publish Package
+
+on:
+  pull_request:
+    branches:
+      - main
+    types:
+      - closed
+
+jobs:
+  publish-package:
+    if: ${{ github.event.pull_request.merged == true && startsWith(github.event.pull_request.head.ref, 'release/v') }}
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repo main branch
+        uses: actions/checkout@v4
+        with:
+          ref: main
+      - name: Set up Python 3.10
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
+        with:
+          version: 1.6.1
+      - name: Configure poetry
+        run: poetry config --no-interaction pypi-token.pypi ${{ secrets.FASTDATATABLE_PYPI_TOKEN }}
+      - name: Get project Version
+        id: project_version
+        run: echo "project_version=$(poetry version --short)" >> $GITHUB_OUTPUT
+      - name: Build package
+        run: poetry build --no-interaction
+      - name: Publish package to PyPI
+        run: poetry publish --no-interaction
+      - name: Create a Github Release
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: v${{ steps.project_version.outputs.project_version }}
+          target_commitish: main
+          token: ${{ secrets.FASTDATATABLE_RELEASE_TOKEN }}
+          body_path: CHANGELOG.md
+          files: |
+            LICENSE
+            dist/*textual_fastdatatable*.whl
+            dist/*textual_fastdatatable*.tar.gz
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@ -0,0 +1,58 @@
+name: Create Release Branch
+
+on:
+  workflow_dispatch:
+    inputs:
+      newVersion:
+        description: A version number for this release (e.g., "0.1.0")
+        required: true
+
+jobs:  
+  prepare-release:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+
+    steps:
+      - name: Check out repo main branch
+        uses: actions/checkout@v4
+        with:
+          ref: main
+      - name: Set up Python 3.10
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
+        with:
+          version: 1.6.1
+      - name: Create release branch
+        run: |
+          git checkout -b release/v${{ github.event.inputs.newVersion }}
+          git push --set-upstream origin release/v${{ github.event.inputs.newVersion }}
+      - name: Bump version
+        run: poetry version ${{ github.event.inputs.newVersion }} --no-interaction
+      - name: Ensure package can be built
+        run: poetry build --no-interaction
+      - name: Update CHANGELOG
+        uses: thomaseizinger/keep-a-changelog-new-release@v3
+        with:
+          version: ${{ github.event.inputs.newVersion }}
+      - name: Commit Changes
+        uses: stefanzweifel/git-auto-commit-action@v5
+        with:
+          commit_message: Bumps version to ${{ github.event.inputs.newVersion }}
+      - name: Create pull request into main
+        uses: thomaseizinger/create-pull-request@1.3.1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          head: release/v${{ github.event.inputs.newVersion }}
+          base: main
+          title: v${{ github.event.inputs.newVersion }}
+          body: >
+            This PR was automatically generated. It bumps the version number
+            in pyproject.toml and updates CHANGELOG.md. You may have to close
+            this PR and reopen it to get the required checks to run.
+
--- a/.github/workflows/static.yml
+++ b/.github/workflows/static.yml
@ -0,0 +1,53 @@
+name: "Perform Static Analysis"
+
+on:
+  pull_request:
+
+# will cancel previous workflows triggered by the same event and for the same ref for PRs or same SHA otherwise
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ contains(github.event_name, 'pull_request') && github.event.pull_request.head.ref || github.sha }}
+  cancel-in-progress: true
+
+jobs:
+  static:
+    name: Static Analysis - 3.11
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out Repo
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Set up Python 3.11
+        uses: actions/setup-python@v5
+        id: setup-python
+        with:
+          python-version: "3.11"
+      - name: Load cached Poetry installation
+        id: cached-poetry-install
+        uses: actions/cache@v4
+        with:
+          path: ~/.local
+          key: poetry-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-0
+      - name: Install Poetry
+        if: steps.cached-poetry-install.outputs.cache-hit != 'true'
+        uses: snok/install-poetry@v1
+        with:
+          version: 1.4.2
+          virtualenvs-create: true
+          virtualenvs-in-project: true
+          installer-parallel: true
+      - name: Load cached venv
+        id: cached-poetry-dependencies
+        uses: actions/cache@v4
+        with:
+          path: .venv
+          key: static-venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('**/poetry.lock') }}
+      - name: Install python dependencies
+        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
+        run: poetry install --sync --no-interaction --without dev
+      - name: Run analysis
+        run: |
+          source .venv/bin/activate
+          ruff format --check
+          ruff check .
+          mypy
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@ -0,0 +1,88 @@
+name: Test
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+
+# will cancel previous workflows triggered by the same event and for the same ref for PRs or same SHA otherwise
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ contains(github.event_name, 'pull_request') && github.event.pull_request.head.ref || github.sha }}
+  cancel-in-progress: true
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  test-windows:
+    name: Windows - 3.10
+    runs-on: Windows-latest
+    steps:
+      - name: Check out Repo
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Set up Python 3.10
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
+        with:
+          version: 1.4.2
+      - name: Install python dependencies
+        run: poetry install --sync --no-interaction --only main,test
+      - name: Run tests
+        run: poetry run pytest
+
+  test:
+    name: ${{ matrix.os }} - ${{ matrix.py }}
+    runs-on: ${{ matrix.os }}-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - ubuntu
+          - MacOs
+        py:
+          - "3.11"
+          - "3.10"
+          - "3.9"
+    steps:
+      - name: Check out Repo
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Set up Python ${{ matrix.py }}
+        id: setup-python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.py }}
+      - name: Load cached Poetry installation
+        id: cached-poetry-install
+        uses: actions/cache@v4
+        with:
+          path: ~/.local
+          key: poetry-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('**/poetry.lock') }}
+      - name: Install Poetry
+        if: steps.cached-poetry-install.outputs.cache-hit != 'true'
+        uses: snok/install-poetry@v1
+        with:
+          version: 1.4.2
+          virtualenvs-create: true
+          virtualenvs-in-project: true
+          installer-parallel: true
+      - name: Load cached venv
+        id: cached-poetry-dependencies
+        uses: actions/cache@v4
+        with:
+          path: .venv
+          key: venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('**/poetry.lock') }}
+      - name: Install python dependencies
+        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
+        run: poetry install --sync --no-interaction --only main,test
+      - name: Run tests
+        run: |
+          source .venv/bin/activate
+          pytest
--- a/.gitignore
+++ b/.gitignore
@ -0,0 +1,167 @@
+.vscode
+snapshot_report.html
+profile*.html
+results.md
+Pipfile
+.python-version
+
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+#poetry.lock
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#pdm.lock
+#   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
+#   in version control.
+#   https://pdm.fming.dev/#use-with-ide
+.pdm.toml
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#.idea/
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@ -0,0 +1,28 @@
+repos:
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: v0.5.1
+    hooks:
+      - id: ruff-format
+      - id: ruff
+        args: [ --fix, --exit-non-zero-on-fix ]
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v1.11.0
+    hooks:
+      - id: mypy
+        additional_dependencies:
+          - textual>=0.72.0
+          - pytest
+          - pyarrow-stubs
+          - pandas-stubs
+          - polars
+        exclude: "tests/snapshot_tests/"
+        args:
+          - "--disallow-untyped-calls"
+          - "--disallow-untyped-defs"
+          - "--disallow-incomplete-defs"
+          - "--strict-optional"
+          - "--warn-return-any"
+          - "--warn-no-return"
+          - "--warn-redundant-casts"
+          - "--no-warn-unused-ignores"
+          - "--allow-untyped-decorators"
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -0,0 +1,181 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+## [Unreleased]
+
+## [0.12.0] - 2025-02-06
+
+- Catch overflow errors when casting arrow temporal types to python date and datetimes, and substitue date.max/min and datetime.max/min, instead of None.
+- Format date.max/min and datetime.max/min with an infinity symbol (`∞`) when rendering cells with those values.
+
+## [0.11.0] - 2024-12-19
+
+- Drops support for Python 3.8
+- Adds support for Python 3.13
+
+## [0.10.0] - 2024-10-31
+
+- Adds an optional parameter to DataTable to disable rendering of string data as Rich Markup.
+- Fixes a bug where None could be casted to a string and displayed as "None" ([tconbeer/harlequin#658](https://github.com/tconbeer/harlequin/issues/658))
+
+## [0.9.0] - 2024-07-23
+
+- Adds a PolarsBackend implementation of DataTableBackend. You must have `polars` installed to use the PolarsBackend. You can install it using the `polars` extra for this package.
+- Fixes a crash from the ArrowBackend when attempting to instantiate negative datetimes after a timezone conversion.
+
+## [0.8.0] - 2024-07-10
+
+- Fixes a crash when cell contents contained bad Rich Markdown ([tconbeer/harlequin#569](https://github.com/tconbeer/harlequin/issues/569)).
+- Improves the appearance of data tooltips.
+
+## [0.7.1] - 2024-02-09
+
+- Adds a `backend.source_data` property to exposue the underlying Arrow table, before slicing.
+
+## [0.7.0] - 2024-02-07
+
+### Breaking Changes
+
+- Removes the NumpyBackend ([#78](https://github.com/tconbeer/textual-fastdatatable/issues/78)).
+
+### Features
+
+- Values are now formatted based on their type. Numbers have separators based on the locale, and numbers, dates/times/etc., and bools are right-aligned ([#70](https://github.com/tconbeer/textual-fastdatatable/issues/70)).
+
+### Bug Fixes
+
+- Fixes bug that caused either a crash or an empty table from initializing a table `from_records` or `from_pydict` with mixed (widening or narrowing) types in one column.
+
+## [0.6.3] - 2024-01-09
+
+### Bug Fixes
+
+- Widens acceptable types for create_backend to accept a sequence of any iterable, not just iterables that are instances of typing.Iterable.
+
+## [0.6.2] - 2024-01-08
+
+### Bug Fixes
+
+- Adds the tzdata package as a dependency for Windows installs, since Windows does not ship with a built-in tzdata database.
+
+## [0.6.1] - 2024-01-05
+
+### Bug Fixes
+
+- Fixes the behavior of <kbd>tab</kbd> and <kbd>shift+tab</kbd> to cycle to the next/prev row if at the end/start of a row or table.
+- Fixes a crash from pressing <kbd>ctrl+c</kbd> when the cursor type is column.
+
+## [0.6.0] - 2024-01-05
+
+### Features
+
+- Adds keybindings for navigating the cursor in the data table. <kbd>ctrl+right/left/up/down/home/end</kbd> (with <kbd>shift</kbd> variants), <kbd>tab</kbd>, <kbd>shift+tab</kbd>, <kbd>ctrl+a</kbd> now all do roughly what they do in Excel (if the cursor type is `range`).
+
+## [0.5.1] - 2024-01-05
+
+### Bug Fixes
+
+- Adds a dependency on pytz for Python &lt;3.9 for timezone support.
+- Fixes a bug where Arrow crashes while casting timestamptz to string ([tconbeer/harlequin#382](https://github.com/tconbeer/harlequin/issues/382)).
+
+### Performance
+
+- Vectorizes fallback string casting for datatypes unsupported by `pc.cast` ([#8](https://github.com/tconbeer/textual-fastdatatable/issues/8))
+
+## [0.5.0] - 2023-12-21
+
+### Features
+
+- Adds a `range` cursor type that will highlight a range of selected cells, like Excel.
+- <kbd>ctrl+c</kbd> now posts a `SelectionCopied` message, with a values attribute that conttains a list of tuples of values from the data table.
+- Adds a `max_column_content_width` parameter to DataTable. If set, DataTable will truncate values longer than the width, but show the full value in a tooltip on hover.
+
+## [0.4.1] - 2023-12-14
+
+- Fixes a crash caused by calling `create_backend` with an empty sequence.
+
+## [0.4.0] - 2023-11-14
+
+### Breaking API Changes
+
+- When calling `create_backend` with a sequence of iterables, the default behavior now assumes the data does not contain headers. You can restore the old behavior with `create_backend(has_headers=True)`.
+- When calling `DataTable(data=...)` with a sequence of iterables, the first row is treated as a header only if `column_labels` is not provided.
+
+## [0.3.0] - 2023-11-11
+
+### Features
+
+- The DataTable now accepts a `max_rows` kwarg; if provided, backends will only store the first `max_rows` and the DataTable will only present `max_rows`. The original row count of the data source is available as DataTable().source_row_count ([tconbeer/harlequin#281](https://github.com/tconbeer/harlequin/issues/281)).
+
+### API Changes
+
+- Backends must now accept a `max_rows` kwarg on initialization.
+
+## [0.2.1] - 2023-11-10
+
+### Bug Fixes
+
+- Tables with the ArrowBackend no longer display incorrect output when column labels are duplicated ([#26](https://github.com/tconbeer/textual-fastdatatable/issues/26)).
+
+## [0.2.0] - 2023-11-08
+
+### Features
+
+- Adds a `null_rep: str` argument when initializing the data table; this string will be used to replace missing data.
+- Adds a `NumpyBackend` that uses Numpy Record Arrays; this backend is marginally slower than the `ArrowBackend` in most scenarios ([#23](https://github.com/tconbeer/textual-fastdatatable/issues/23)).
+
+### Bug Fixes
+
+- Fixes a crash when using `ArrowBackend.from_records(has_header=False)`.
+
+### Performance
+
+- Drastically improves performance for tables that are much wider than the viewport ([#12](https://github.com/tconbeer/textual-fastdatatable/issues/12)). 
+
+### Benchmarks
+
+- Improves benchmarks to exclude data load times, disable garbage collection, and include more information about first paint and scroll performance.
+
+## [0.1.4] - 2023-11-06
+
+- Fixes a crash when computing the widths of columns with no rows ([#19](https://github.com/tconbeer/textual-fastdatatable/issues/19)).
+
+## [0.1.3] - 2023-10-09
+
+- Fixes a crash when creating a column from a null or complex type.
+
+## [0.1.2] - 2023-10-02
+
+## [0.1.1] - 2023-09-29
+
+- Fixes a crash when rows were added to an empty table.
+
+## [0.1.0] - 2023-09-29
+
+- Initial release. Adds DataTable and ArrowBackend, which is 1000x faster for datasets of 500k records or more.
+
+[unreleased]: https://github.com/tconbeer/textual-fastdatatable/compare/0.12.0...HEAD
+[0.12.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.11.0...0.12.0
+[0.11.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.10.0...0.11.0
+[0.10.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.9.0...0.10.0
+[0.9.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.8.0...0.9.0
+[0.8.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.7.1...0.8.0
+[0.7.1]: https://github.com/tconbeer/textual-fastdatatable/compare/0.7.0...0.7.1
+[0.7.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.6.3...0.7.0
+[0.6.3]: https://github.com/tconbeer/textual-fastdatatable/compare/0.6.2...0.6.3
+[0.6.2]: https://github.com/tconbeer/textual-fastdatatable/compare/0.6.1...0.6.2
+[0.6.1]: https://github.com/tconbeer/textual-fastdatatable/compare/0.6.0...0.6.1
+[0.6.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.5.1...0.6.0
+[0.5.1]: https://github.com/tconbeer/textual-fastdatatable/compare/0.5.0...0.5.1
+[0.5.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.4.1...0.5.0
+[0.4.1]: https://github.com/tconbeer/textual-fastdatatable/compare/0.4.0...0.4.1
+[0.4.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.3.0...0.4.0
+[0.3.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.2.1...0.3.0
+[0.2.1]: https://github.com/tconbeer/textual-fastdatatable/compare/0.2.0...0.2.1
+[0.2.0]: https://github.com/tconbeer/textual-fastdatatable/compare/0.1.4...0.2.0
+[0.1.4]: https://github.com/tconbeer/textual-fastdatatable/compare/0.1.3...0.1.4
+[0.1.3]: https://github.com/tconbeer/textual-fastdatatable/compare/0.1.2...0.1.3
+[0.1.2]: https://github.com/tconbeer/textual-fastdatatable/compare/0.1.1...0.1.2
+[0.1.1]: https://github.com/tconbeer/textual-fastdatatable/compare/0.1.0...0.1.1
+[0.1.0]: https://github.com/tconbeer/textual-fastdatatable/compare/4b9f99175d34f693dd0d4198c39d72f89caf6479...0.1.0
--- a/21
+++ b/21
@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Ted Conbeer
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
--- a/24
+++ b/24
@ -0,0 +1,24 @@
+.PHONY: check
+check:
+	ruff format .
+	pytest
+	ruff check . --fix
+	mypy
+
+.PHONY: lint
+lint:
+	ruff format .
+	ruff check . --fix
+	mypy
+
+.PHONY: serve
+serve:
+	textual run --dev -c python -m textual_fastdatatable
+
+.PHONY: profile
+profile:
+	pyinstrument -r html -o profile.html "src/scripts/run_arrow_wide.py"
+
+.PHONY: benchmark
+benchmark:
+	python src/scripts/benchmark.py > /dev/null
--- a/README.md
+++ b/README.md
@ -0,0 +1,131 @@
+# textual-fastdatatable
+A performance-focused reimplementation of Textual's DataTable widget, with a pluggable data storage backend.
+
+Textual's built-in DataTable widget is beautiful and powerful, but it can be slow to load large datasets.
+
+Here are some benchmarks on my relatively weak laptop. For each benchmark, we initialize a Textual App that
+loads a dataset from a parquet file and mounts a data table; it then scrolls around the table
+(10 pagedowns and 15 right arrows). 
+
+For the built-in table and the others marked "from Records", the data is loaded into memory before the timer
+is started; for the "Arrow from Parquet" back-end, the timer is started immediately.
+
+The times in each column represent the time to the first paint of the table, and the time after scrolling
+is completed (we wait until the table is fully rendered after each scroll):
+
+Records | Built-In DataTable | FastDataTable (Arrow from Parquet) | FastDataTable (Arrow from Records) | FastDataTable (Numpy from Records) 
+--------|--------|--------|--------|--------
+lap_times_100.parquet |   0.019s /   1.716s |   0.012s /   1.724s |    0.011s /   1.700s |   0.011s /   1.688s
+lap_times_1000.parquet |   0.103s /   1.931s |   0.011s /   1.859s |    0.011s /   1.799s |   0.015s /   1.848s
+lap_times_10000.parquet |   0.977s /   2.824s |   0.013s /   1.834s |    0.016s /   1.812s |   0.078s /   1.869s
+lap_times_100000.parquet |  11.773s /  13.770s |   0.025s /   1.790s |    0.156s /   1.824s |   0.567s /   2.347s
+lap_times_538121.parquet |  62.960s /  65.760s |   0.077s /   1.803s |    0.379s /   2.234s |   3.324s /   5.031s
+wide_10000.parquet |   5.110s /  10.539s |   0.024s /   3.373s |    0.042s /   3.278s |   0.369s /   3.461s
+wide_100000.parquet |  51.144s /  56.604s |   0.054s /   3.294s |    0.429s /   3.642s |   3.628s /   6.732s
+
+
+**NB:** FastDataTable currently does not support rows with a height of more than one line. See below for
+more limitations, relative to the built-in DataTable.
+
+## Installation
+
+```bash
+pip install textual-fastdatatable
+```
+
+## Usage
+
+If you already have data in Apache Arrow or another common table format:
+
+```py
+from textual_fastdatatable import DataTable
+data_table = DataTable(data = my_data)
+```
+
+The currently supported types are:
+
+```py
+AutoBackendType = Union[
+    pa.Table,
+    pa.RecordBatch,
+    Path, # to parquet only
+    str, # path to parquet only
+    Sequence[Iterable[Any]],
+    Mapping[str, Sequence[Any]],
+]
+```
+
+To override the column labels and widths supplied by the backend:
+```py
+from textual_fastdatatable import DataTable
+data_table = DataTable(data = my_data, column_labels=["Supports", "[red]Console[/]", "Markup!"], column_widths=[10, 5, None])
+```
+
+You can also pass in a `backend` manually (if you want more control or want to plug in your own).
+
+```py
+from textual_fastdatatable import ArrowBackend, DataTable, create_backend
+backend = create_backend(my_data)
+backend = ArrowBackend(my_arrow_table)
+# from python dictionary in the form key: col_values
+backend = ArrowBackend.from_pydict(
+    {
+        "col one": [1, 2, 3 ,4],
+        "col two": ["a", "b", "c", "d"],
+    }
+)
+# from a list of tuples or another sequence of iterables
+backend = ArrowBackend.from_records(
+    [
+        ("col one", "col two"),
+        (1, "a"),
+        (2, "b"),
+        (3, "c"),
+        (4, "d"),
+    ]
+)
+# from a path to a Parquet file:
+backend = ArrowBackend.from_parquet("path/to/file.parquet")
+```
+
+## Limitations and Caveats
+
+The `DataTable` does not currently support rows with a height of more than one line. Only the first line of each row will be displayed.
+
+The `DataTable` does not currently support row labels.
+
+The `ArrowBackend` is optimized to be fast for large, immutable datasets. Mutating the data,
+especially adding or removing rows, may be slow.
+
+The `ArrowBackend` cannot be initialized without data, however, the DataTable can (either with or without `column_labels`).
+
+The `ArrowBackend` cannot store arbitrary Python objects or Rich Renderables as values. It may widen types to strings unnecessarily.
+
+## Additional Features
+
+### Copying Data from the Table
+
+`ctrl+c` will post a SelectionCopied message with a list of tuples of the values selected by the cursor. To use, initialize with `cursor_type=range` from an app that does NOT inherit bindings.
+
+```py
+from textual.app import App, ComposeResult
+
+from textual_fastdatatable import ArrowBackend, DataTable
+
+
+class TableApp(App, inherit_bindings=False):
+    BINDINGS = [("ctrl+q", "quit", "Quit")]
+
+    def compose(self) -> ComposeResult:
+        backend = ArrowBackend.from_parquet("./tests/data/lap_times_538121.parquet")
+        yield DataTable(backend=backend, cursor_type="range")
+
+
+if __name__ == "__main__":
+    app = TableApp()
+    app.run()
+```
+
+### Truncating long values
+
+The `DataTable` will automatically calculate column widths; if you set a `max_column_content_width` at initialization, it will truncate any long values at that width; the full value will be visible on hover in a tooltip (and the full value will always be copied to the clipboard).
--- a/poetry.lock
+++ b/poetry.lock
--- a/pyproject.toml
+++ b/pyproject.toml
@ -0,0 +1,81 @@
+[tool.poetry]
+name = "textual-fastdatatable"
+version = "0.12.0"
+description = "A performance-focused reimplementation of Textual's DataTable widget, with a pluggable data storage backend."
+authors = ["Ted Conbeer <tconbeer@users.noreply.github.com>"]
+license = "MIT"
+readme = "README.md"
+packages = [
+    { include = "textual_fastdatatable", from = "src" },
+]
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"
+
+
+[tool.poetry.dependencies]
+python = ">=3.9,<3.14"
+textual = ">=0.89.1"
+pyarrow = ">=16.1.0"
+polars = { version = ">=0.20.0", optional = true } 
+tzdata = { version = ">=2023", markers = "sys_platform == 'win32'" } # arrow timestamptz support on windows
+
+[tool.poetry.extras]
+polars = ["polars"]
+
+[tool.poetry.group.dev.dependencies]
+pre-commit = "^3.3.1"
+textual-dev = "^1.0.1"
+pandas = "^2.1.1"
+numpy = "^1"
+pyinstrument = "^5"
+
+[tool.poetry.group.static.dependencies]
+ruff = "^0.5"
+mypy = "^1.10.0"
+pandas-stubs = "^2.1.1"
+
+[tool.poetry.group.test.dependencies]
+pytest = "^7.3.1"
+pytest-asyncio = ">=0.21,<0.24"
+pytest-textual-snapshot = ">=0.4.0"
+polars = ">=0.20.0"
+
+
+[tool.ruff]
+target-version = "py39"
+
+[tool.ruff.lint]
+select = ["A", "B", "E", "F", "I"]
+
+[tool.mypy]
+python_version = "3.9"
+files = [
+    "src/**/*.py",
+    "tests/unit_tests/**/*.py"
+]
+mypy_path = "src:stubs"
+
+show_column_numbers = true
+
+# show error messages from unrelated files
+follow_imports = "normal"
+
+# be strict
+disallow_untyped_calls = true
+disallow_untyped_defs = true
+check_untyped_defs = true
+disallow_untyped_decorators = true
+disallow_incomplete_defs = true
+disallow_subclassing_any = true
+strict_optional = true
+
+warn_return_any = true
+warn_no_return = true
+warn_redundant_casts = true
+warn_unused_ignores = true
+warn_unused_configs = true
+
+no_implicit_reexport = true
+strict_equality = true
--- a/src/scripts/benchmark.py
+++ b/src/scripts/benchmark.py
@ -0,0 +1,157 @@
+from __future__ import annotations
+
+import gc
+from pathlib import Path
+from time import perf_counter
+
+import pandas as pd
+import polars as pl
+from textual.app import App, ComposeResult
+from textual.driver import Driver
+from textual.pilot import Pilot
+from textual.types import CSSPathType
+from textual.widgets import DataTable as BuiltinDataTable
+from textual_fastdatatable import ArrowBackend
+from textual_fastdatatable import DataTable as FastDataTable
+from textual_fastdatatable.backend import PolarsBackend
+
+BENCHMARK_DATA = Path(__file__).parent.parent.parent / "tests" / "data"
+
+
+async def scroller(pilot: Pilot) -> None:
+    first_paint = perf_counter() - pilot.app.start  # type: ignore
+    for _ in range(5):
+        await pilot.press("pagedown")
+    for _ in range(15):
+        await pilot.press("right")
+    for _ in range(5):
+        await pilot.press("pagedown")
+    elapsed = perf_counter() - pilot.app.start  # type: ignore
+    pilot.app.exit(result=(first_paint, elapsed))
+
+
+class BuiltinApp(App):
+    TITLE = "Built-In DataTable"
+
+    def __init__(
+        self,
+        data_path: Path,
+        driver_class: type[Driver] | None = None,
+        css_path: CSSPathType | None = None,
+        watch_css: bool = False,
+    ):
+        super().__init__(driver_class, css_path, watch_css)
+        self.data_path = data_path
+
+    def compose(self) -> ComposeResult:
+        df = pd.read_parquet(self.data_path)
+        rows = [tuple(row) for row in df.itertuples(index=False)]
+        self.start = perf_counter()
+        table: BuiltinDataTable = BuiltinDataTable()
+        table.add_columns(*[str(col) for col in df.columns])
+        for row in rows:
+            table.add_row(*row, height=1, label=None)
+        yield table
+
+
+class ArrowBackendApp(App):
+    TITLE = "FastDataTable (Arrow from Parquet)"
+
+    def __init__(
+        self,
+        data_path: Path,
+        driver_class: type[Driver] | None = None,
+        css_path: CSSPathType | None = None,
+        watch_css: bool = False,
+    ):
+        super().__init__(driver_class, css_path, watch_css)
+        self.data_path = data_path
+
+    def compose(self) -> ComposeResult:
+        self.start = perf_counter()
+        yield FastDataTable(data=self.data_path)
+
+
+class ArrowBackendAppFromRecords(App):
+    TITLE = "FastDataTable (Arrow from Records)"
+
+    def __init__(
+        self,
+        data_path: Path,
+        driver_class: type[Driver] | None = None,
+        css_path: CSSPathType | None = None,
+        watch_css: bool = False,
+    ):
+        super().__init__(driver_class, css_path, watch_css)
+        self.data_path = data_path
+
+    def compose(self) -> ComposeResult:
+        df = pd.read_parquet(self.data_path)
+        rows = [tuple(row) for row in df.itertuples(index=False)]
+        self.start = perf_counter()
+        backend = ArrowBackend.from_records(rows, has_header=False)
+        table = FastDataTable(
+            backend=backend, column_labels=[str(col) for col in df.columns]
+        )
+        yield table
+
+
+class PolarsBackendApp(App):
+    TITLE = "FastDataTable (Polars from Parquet)"
+
+    def __init__(
+        self,
+        data_path: Path,
+        driver_class: type[Driver] | None = None,
+        css_path: CSSPathType | None = None,
+        watch_css: bool = False,
+    ):
+        super().__init__(driver_class, css_path, watch_css)
+        self.data_path = data_path
+
+    def compose(self) -> ComposeResult:
+        self.start = perf_counter()
+        yield FastDataTable(
+            data=PolarsBackend.from_dataframe(pl.read_parquet(self.data_path))
+        )
+
+
+if __name__ == "__main__":
+    app_defs = [
+        BuiltinApp,
+        ArrowBackendApp,
+        ArrowBackendAppFromRecords,
+        PolarsBackendApp,
+    ]
+    bench = [
+        (f"lap_times_{n}.parquet", 3 if n <= 10000 else 1)
+        for n in [100, 1000, 10000, 100000, 538121]
+    ]
+    bench.extend([(f"wide_{n}.parquet", 1) for n in [10000, 100000]])
+    with open("results.md", "w") as f:
+        print(
+            "Records |",
+            " | ".join([a.TITLE for a in app_defs]),  # type: ignore
+            sep="",
+            file=f,
+        )
+        print("--------|", "|".join(["--------" for _ in app_defs]), sep="", file=f)
+        for p, tries in bench:
+            first_paint: list[list[float]] = [list() for _ in app_defs]
+            elapsed: list[list[float]] = [list() for _ in app_defs]
+            for i, app_cls in enumerate(app_defs):
+                for _ in range(tries):
+                    app = app_cls(BENCHMARK_DATA / p)
+                    gc.disable()
+                    fp, el = app.run(headless=True, auto_pilot=scroller)  # type: ignore
+                    gc.collect()
+                    first_paint[i].append(fp)
+                    elapsed[i].append(el)
+            gc.enable()
+            avg_first_paint = [sum(app_times) / tries for app_times in first_paint]
+            avg_elapsed = [sum(app_times) / tries for app_times in elapsed]
+            formatted = [
+                f"{fp:7,.3f}s / {el:7,.3f}s"
+                for fp, el in zip(avg_first_paint, avg_elapsed)
+            ]
+            print(f"{p} | {' | '.join(formatted)}", file=f)
--- a/src/scripts/run_arrow_wide.py
+++ b/src/scripts/run_arrow_wide.py
@ -0,0 +1,32 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+from textual.app import App, ComposeResult
+from textual.driver import Driver
+from textual.types import CSSPathType
+from textual_fastdatatable import DataTable
+
+BENCHMARK_DATA = Path(__file__).parent.parent.parent / "tests" / "data"
+
+
+class ArrowBackendApp(App):
+    TITLE = "FastDataTable (Arrow)"
+
+    def __init__(
+        self,
+        data_path: Path,
+        driver_class: type[Driver] | None = None,
+        css_path: CSSPathType | None = None,
+        watch_css: bool = False,
+    ):
+        super().__init__(driver_class, css_path, watch_css)
+        self.data_path = data_path
+
+    def compose(self) -> ComposeResult:
+        yield DataTable(data=self.data_path)
+
+
+if __name__ == "__main__":
+    app = ArrowBackendApp(data_path=BENCHMARK_DATA / "wide_100000.parquet")
+    app.run()
--- a/src/scripts/run_builtin_wide.py
+++ b/src/scripts/run_builtin_wide.py
@ -0,0 +1,39 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+import pandas as pd
+from textual.app import App, ComposeResult
+from textual.driver import Driver
+from textual.types import CSSPathType
+from textual.widgets import DataTable
+
+BENCHMARK_DATA = Path(__file__).parent.parent.parent / "tests" / "data"
+
+
+class BuiltinApp(App):
+    TITLE = "Built-In DataTable"
+
+    def __init__(
+        self,
+        data_path: Path,
+        driver_class: type[Driver] | None = None,
+        css_path: CSSPathType | None = None,
+        watch_css: bool = False,
+    ):
+        super().__init__(driver_class, css_path, watch_css)
+        self.data_path = data_path
+
+    def compose(self) -> ComposeResult:
+        df = pd.read_parquet(self.data_path)
+        rows = [tuple(row) for row in df.itertuples(index=False)]
+        table: DataTable = DataTable()
+        table.add_columns(*[str(col) for col in df.columns])
+        for row in rows:
+            table.add_row(*row, height=1, label=None)
+        yield table
+
+
+if __name__ == "__main__":
+    app = BuiltinApp(data_path=BENCHMARK_DATA / "wide_10000.parquet")
+    app.run()
--- a/src/textual_fastdatatable/init.py
+++ b/src/textual_fastdatatable/init.py
@ -0,0 +1,13 @@
+from textual_fastdatatable.backend import (
+    ArrowBackend,
+    DataTableBackend,
+    create_backend,
+)
+from textual_fastdatatable.data_table import DataTable
+
+__all__ = [
+    "DataTable",
+    "ArrowBackend",
+    "DataTableBackend",
+    "create_backend",
+]
--- a/src/textual_fastdatatable/main.py
+++ b/src/textual_fastdatatable/main.py
@ -0,0 +1,19 @@
+from textual.app import App, ComposeResult
+
+from textual_fastdatatable import ArrowBackend, DataTable
+
+
+class TableApp(App, inherit_bindings=False):
+    BINDINGS = [("ctrl+q", "quit", "Quit"), ("ctrl+d", "quit", "Quit")]
+
+    def compose(self) -> ComposeResult:
+        backend = ArrowBackend.from_parquet("./tests/data/wide_100000.parquet")
+        yield DataTable(backend=backend, cursor_type="range", fixed_columns=2)
+
+
+if __name__ == "__main__":
+    import locale
+
+    locale.setlocale(locale.LC_ALL, "")
+    app = TableApp()
+    app.run()
--- a/src/textual_fastdatatable/backend.py
+++ b/src/textual_fastdatatable/backend.py
@ -0,0 +1,706 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from contextlib import suppress
+from datetime import date, datetime
+from pathlib import Path
+from typing import (
+    Any,
+    Dict,
+    Generic,
+    Iterable,
+    Literal,
+    Mapping,
+    Sequence,
+    TypeVar,
+)
+
+import pyarrow as pa
+import pyarrow.compute as pc
+import pyarrow.lib as pal
+import pyarrow.parquet as pq
+import pyarrow.types as pt
+from rich.console import Console
+
+from textual_fastdatatable.formatter import measure_width
+
+AutoBackendType = Any
+
+try:
+    import polars as pl
+    import polars.datatypes as pld
+except ImportError:
+    _HAS_POLARS = False
+else:
+    _HAS_POLARS = True
+
+
+def create_backend(
+    data: "AutoBackendType",
+    max_rows: int | None = None,
+    has_header: bool = False,
+) -> DataTableBackend:
+    if isinstance(data, pa.Table):
+        return ArrowBackend(data, max_rows=max_rows)
+    if isinstance(data, pa.RecordBatch):
+        return ArrowBackend.from_batches(data, max_rows=max_rows)
+    if _HAS_POLARS and isinstance(data, pl.DataFrame):
+        return PolarsBackend.from_dataframe(data, max_rows=max_rows)
+
+    if isinstance(data, Path) or isinstance(data, str):
+        data = Path(data)
+        if data.suffix in [".pqt", ".parquet"]:
+            return ArrowBackend.from_parquet(data, max_rows=max_rows)
+        if _HAS_POLARS:
+            return PolarsBackend.from_file_path(
+                data, max_rows=max_rows, has_header=has_header
+            )
+    if isinstance(data, Sequence) and not data:
+        return ArrowBackend(pa.table([]), max_rows=max_rows)
+    if isinstance(data, Sequence) and _is_iterable(data[0]):
+        return ArrowBackend.from_records(data, max_rows=max_rows, has_header=has_header)
+
+    if (
+        isinstance(data, Mapping)
+        and isinstance(next(iter(data.keys())), str)
+        and isinstance(next(iter(data.values())), Sequence)
+    ):
+        return ArrowBackend.from_pydict(data, max_rows=max_rows)
+
+    raise TypeError(
+        f"Cannot automatically create backend for data of type: {type(data)}. "
+        f"Data must be of type: Union[pa.Table, pa.RecordBatch, Path, str, "
+        "Sequence[Iterable[Any]], Mapping[str, Sequence[Any]], pl.DataFrame",
+    )
+
+
+def _is_iterable(item: Any) -> bool:
+    try:
+        iter(item)
+    except TypeError:
+        return False
+    else:
+        return True
+
+
+_TableTypeT = TypeVar("_TableTypeT")
+
+
+class DataTableBackend(ABC, Generic[_TableTypeT]):
+    data: _TableTypeT
+
+    @abstractmethod
+    def __init__(self, data: _TableTypeT, max_rows: int | None = None) -> None:
+        pass
+
+    @classmethod
+    @abstractmethod
+    def from_pydict(
+        cls, data: Mapping[str, Sequence[Any]], max_rows: int | None = None
+    ) -> "DataTableBackend":
+        pass
+
+    @property
+    @abstractmethod
+    def source_data(self) -> _TableTypeT:
+        """
+        Return the source data as an Arrow table
+        """
+        pass
+
+    @property
+    @abstractmethod
+    def source_row_count(self) -> int:
+        """
+        The number of rows in the source data, before filtering down to max_rows
+        """
+        pass
+
+    @property
+    @abstractmethod
+    def row_count(self) -> int:
+        """
+        The number of rows in backend's retained data, after filtering down to max_rows
+        """
+        pass
+
+    @property
+    def column_count(self) -> int:
+        return len(self.columns)
+
+    @property
+    @abstractmethod
+    def columns(self) -> Sequence[str]:
+        """
+        A list of column labels
+        """
+        pass
+
+    @property
+    @abstractmethod
+    def column_content_widths(self) -> Sequence[int]:
+        """
+        A list of integers corresponding to the widest utf8 string length
+        of any data in each column.
+        """
+        pass
+
+    @abstractmethod
+    def get_row_at(self, index: int) -> Sequence[Any]:
+        pass
+
+    @abstractmethod
+    def get_column_at(self, index: int) -> Sequence[Any]:
+        pass
+
+    @abstractmethod
+    def get_cell_at(self, row_index: int, column_index: int) -> Any:
+        pass
+
+    @abstractmethod
+    def append_column(self, label: str, default: Any | None = None) -> int:
+        """
+        Returns column index
+        """
+
+    @abstractmethod
+    def append_rows(self, records: Iterable[Iterable[Any]]) -> list[int]:
+        """
+        Returns new row indicies
+        """
+        pass
+
+    @abstractmethod
+    def drop_row(self, row_index: int) -> None:
+        pass
+
+    @abstractmethod
+    def update_cell(self, row_index: int, column_index: int, value: Any) -> None:
+        """
+        Raises IndexError if bad indicies
+        """
+
+    @abstractmethod
+    def sort(
+        self, by: list[tuple[str, Literal["ascending", "descending"]]] | str
+    ) -> None:
+        """
+        by: str sorts table by the data in the column with that name (asc).
+        by: list[tuple] sorts the table by the named column(s) with the directions
+            indicated.
+        """
+
+
+class ArrowBackend(DataTableBackend[pa.Table]):
+    def __init__(self, data: pa.Table, max_rows: int | None = None) -> None:
+        self._source_data = data
+
+        # Arrow allows duplicate field names, but a table's to_pylist() and
+        # to_pydict() methods will drop duplicate-named fields!
+        field_names: list[str] = []
+        renamed = False
+        for field in data.column_names:
+            n = 0
+            while field in field_names:
+                field = f"{field}{n}"
+                renamed = True
+                n += 1
+            field_names.append(field)
+        if renamed:
+            data = data.rename_columns(field_names)
+
+        self._source_row_count = data.num_rows
+        if max_rows is not None and max_rows < self._source_row_count:
+            self.data = data.slice(offset=0, length=max_rows)
+        else:
+            self.data = data
+        self._console = Console()
+        self._column_content_widths: list[int] = []
+
+    @staticmethod
+    def _pydict_from_records(
+        records: Sequence[Iterable[Any]], has_header: bool = False
+    ) -> dict[str, list[Any]]:
+        headers = (
+            records[0]
+            if has_header
+            else [f"f{i}" for i in range(len(list(records[0])))]
+        )
+        data = list(map(list, records[1:] if has_header else records))
+        pydict = {header: [row[i] for row in data] for i, header in enumerate(headers)}
+        return pydict
+
+    @staticmethod
+    def _handle_overflow(scalar: pa.Scalar) -> Any | None:
+        """
+        PyArrow may throw an OverflowError when casting arrow types
+        to python types; in some cases we can catch these and
+        present a sensible value in the data table; otherwise
+        we return None.
+        """
+        if pt.is_date32(scalar.type):
+            if scalar.value > 0:  # type: ignore[attr-defined]
+                return date.max
+            elif scalar.value <= 0:  # type: ignore[attr-defined]
+                return date.min
+        elif pt.is_date64(scalar.type):
+            if scalar.value > 0:  # type: ignore[attr-defined]
+                return date.max
+            elif scalar.value <= 0:  # type: ignore[attr-defined]
+                return date.min
+        elif pt.is_timestamp(scalar.type):
+            if scalar.value > 0:  # type: ignore[attr-defined]
+                return datetime.max
+            elif scalar.value <= 0:  # type: ignore[attr-defined]
+                return datetime.min
+
+        return None
+
+    @classmethod
+    def from_batches(
+        cls, data: pa.RecordBatch, max_rows: int | None = None
+    ) -> "ArrowBackend":
+        tbl = pa.Table.from_batches([data])
+        return cls(tbl, max_rows=max_rows)
+
+    @classmethod
+    def from_parquet(
+        cls, path: Path | str, max_rows: int | None = None
+    ) -> "ArrowBackend":
+        tbl = pq.read_table(str(path))
+        return cls(tbl, max_rows=max_rows)
+
+    @classmethod
+    def from_pydict(
+        cls, data: Mapping[str, Sequence[Any]], max_rows: int | None = None
+    ) -> "ArrowBackend":
+        try:
+            tbl = pa.Table.from_pydict(dict(data))
+        except (pal.ArrowInvalid, pal.ArrowTypeError):
+            # one or more fields has mixed types, like int and
+            # string. Cast all to string for safety
+            new_data = {
+                k: [str(val) if val is not None else None for val in v]
+                for k, v in data.items()
+            }
+            tbl = pa.Table.from_pydict(new_data)
+        return cls(tbl, max_rows=max_rows)
+
+    @classmethod
+    def from_records(
+        cls,
+        records: Sequence[Iterable[Any]],
+        has_header: bool = False,
+        max_rows: int | None = None,
+    ) -> "ArrowBackend":
+        pydict = cls._pydict_from_records(records, has_header)
+        return cls.from_pydict(pydict, max_rows=max_rows)
+
+    @property
+    def source_data(self) -> pa.Table:
+        return self._source_data
+
+    @property
+    def source_row_count(self) -> int:
+        return self._source_row_count
+
+    @property
+    def row_count(self) -> int:
+        return self.data.num_rows
+
+    @property
+    def column_count(self) -> int:
+        return self.data.num_columns
+
+    @property
+    def columns(self) -> Sequence[str]:
+        return self.data.column_names
+
+    @property
+    def column_content_widths(self) -> list[int]:
+        if not self._column_content_widths:
+            measurements = [self._measure(arr) for arr in self.data.columns]
+            # pc.max returns None for each column without rows; we need to return 0
+            # instead.
+            self._column_content_widths = [cw or 0 for cw in measurements]
+
+        return self._column_content_widths
+
+    def get_row_at(self, index: int) -> Sequence[Any]:
+        try:
+            row: Dict[str, Any] = self.data.slice(index, length=1).to_pylist()[0]
+        except OverflowError:
+            return [
+                self._handle_overflow(self.data[i][index])
+                for i in range(len(self.columns))
+            ]
+        else:
+            return list(row.values())
+
+    def get_column_at(self, column_index: int) -> list[Any]:
+        try:
+            values = self.data[column_index].to_pylist()
+        except OverflowError:
+            # TODO: consider registering a scalar UDF here for parallel processing
+            return [self._handle_overflow(scalar) for scalar in self.data[column_index]]
+        else:
+            return values
+
+    def get_cell_at(self, row_index: int, column_index: int) -> Any:
+        scalar = self.data[column_index][row_index]
+        try:
+            value = scalar.as_py()
+        except OverflowError:
+            value = self._handle_overflow(scalar)
+        return value
+
+    def append_column(self, label: str, default: Any | None = None) -> int:
+        """
+        Returns column index
+        """
+        if default is None:
+            arr: pa.Array = pa.nulls(self.row_count)
+        else:
+            arr = pa.nulls(self.row_count, type=pa.string())
+            arr = arr.fill_null(str(default))
+
+        self.data = self.data.append_column(label, arr)
+        if self._column_content_widths:
+            self._column_content_widths.append(measure_width(default, self._console))
+        return self.data.num_columns - 1
+
+    def append_rows(self, records: Iterable[Iterable[Any]]) -> list[int]:
+        rows = list(records)
+        indicies = list(range(self.row_count, self.row_count + len(rows)))
+        records_with_headers = [self.data.column_names, *rows]
+        pydict = self._pydict_from_records(records_with_headers, has_header=True)
+        old_rows = self.data.to_batches()
+        new_rows = pa.RecordBatch.from_pydict(
+            pydict,
+            schema=self.data.schema,
+        )
+        self.data = pa.Table.from_batches([*old_rows, new_rows])
+        self._reset_content_widths()
+        return indicies
+
+    def drop_row(self, row_index: int) -> None:
+        if row_index < 0 or row_index >= self.row_count:
+            raise IndexError(f"Can't drop row {row_index} of {self.row_count}")
+        above = self.data.slice(0, row_index).to_batches()
+        below = self.data.slice(row_index + 1).to_batches()
+        self.data = pa.Table.from_batches([*above, *below])
+        self._reset_content_widths()
+        pass
+
+    def update_cell(self, row_index: int, column_index: int, value: Any) -> None:
+        column = self.data.column(column_index)
+        pycolumn = self.get_column_at(column_index=column_index)
+        pycolumn[row_index] = value
+        new_type = pa.string() if pt.is_null(column.type) else column.type
+        self.data = self.data.set_column(
+            column_index,
+            self.data.column_names[column_index],
+            pa.array(pycolumn, type=new_type),
+        )
+        if self._column_content_widths:
+            self._column_content_widths[column_index] = max(
+                measure_width(value, self._console),
+                self._column_content_widths[column_index],
+            )
+
+    def sort(
+        self, by: list[tuple[str, Literal["ascending", "descending"]]] | str
+    ) -> None:
+        """
+        by: str sorts table by the data in the column with that name (asc).
+        by: list[tuple] sorts the table by the named column(s) with the directions
+            indicated.
+        """
+        self.data = self.data.sort_by(by)
+
+    def _reset_content_widths(self) -> None:
+        self._column_content_widths = []
+
+    def _measure(self, arr: pa._PandasConvertible) -> int:
+        # with some types we can measure the width more efficiently
+        if pt.is_boolean(arr.type):
+            return 7
+        elif pt.is_null(arr.type):
+            return 0
+        elif (
+            pt.is_integer(arr.type)
+            or pt.is_floating(arr.type)
+            or pt.is_decimal(arr.type)
+        ):
+            try:
+                col_max = pc.max(arr.fill_null(0)).as_py()
+            except OverflowError:
+                col_max = 9223372036854775807
+            try:
+                col_min = pc.min(arr.fill_null(0)).as_py()
+            except OverflowError:
+                col_min = -9223372036854775807
+            return max([measure_width(el, self._console) for el in [col_max, col_min]])
+        elif pt.is_temporal(arr.type):
+            try:
+                value = arr.drop_null()[0].as_py()
+            except OverflowError:
+                return 26  # need space for the infinity sign and a space
+            except IndexError:
+                return 24
+            else:
+                # valid temporal types all have the same width for their type
+                return measure_width(value, self._console)
+
+        # for everything else, we need to compute it
+        # First, cast the data to strings
+        try:
+            arr = arr.cast(
+                pa.string(),
+                safe=False,
+            )
+        except (pal.ArrowNotImplementedError, pal.ArrowInvalid):
+            # some types can't be casted to strings natively by arrow, but they
+            # can be casted to strings by python. The arrow way is faster, but
+            # if it fails, register a python udf and try again
+            def py_str(_ctx: Any, arr: pa.Array) -> str | pa.Array | pa.ChunkedArray:
+                return pa.array([str(el) for el in arr], type=pa.string())
+
+            udf_name = f"tfdt_pystr_{arr.type}"
+            with suppress(pal.ArrowKeyError):  # already registered
+                pc.register_scalar_function(
+                    py_str,
+                    function_name=udf_name,
+                    function_doc={"summary": "str", "description": "built-in str"},
+                    in_types={"arr": arr.type},
+                    out_type=pa.string(),
+                )
+
+            arr = pc.call_function(udf_name, [arr])
+
+        # next, try to measure the UTF-encoded string length of each cell,
+        # then take the max
+        try:
+            width: int = pc.max(pc.utf8_length(arr.fill_null("")).fill_null(0)).as_py()
+        except OverflowError:
+            width = 10
+        return width
+
+
+if _HAS_POLARS:
+
+    class PolarsBackend(DataTableBackend[pl.DataFrame]):
+        @classmethod
+        def from_file_path(
+            cls, path: Path, max_rows: int | None = None, has_header: bool = True
+        ) -> "PolarsBackend":
+            if path.suffix in [".arrow", ".feather"]:
+                tbl = pl.read_ipc(path)
+            elif path.suffix == ".arrows":
+                tbl = pl.read_ipc_stream(path)
+            elif path.suffix == ".json":
+                tbl = pl.read_json(path)
+            elif path.suffix == ".csv":
+                tbl = pl.read_csv(path, has_header=has_header)
+            else:
+                raise TypeError(
+                    f"Dont know how to load file type {path.suffix} for {path}"
+                )
+            return cls(tbl, max_rows=max_rows)
+
+        @classmethod
+        def from_pydict(
+            cls, pydict: Mapping[str, Sequence[Any]], max_rows: int | None = None
+        ) -> "PolarsBackend":
+            return cls(pl.from_dict(pydict), max_rows=max_rows)
+
+        @classmethod
+        def from_dataframe(
+            cls, frame: pl.DataFrame, max_rows: int | None = None
+        ) -> "PolarsBackend":
+            return cls(frame, max_rows=max_rows)
+
+        def __init__(self, data: pl.DataFrame, max_rows: int | None = None) -> None:
+            self._source_data = data
+
+            # Arrow allows duplicate field names, but a table's to_pylist() and
+            # to_pydict() methods will drop duplicate-named fields!
+            field_names: list[str] = []
+            for field in data.columns:
+                n = 0
+                while field in field_names:
+                    field = f"{field}{n}"
+                    n += 1
+                field_names.append(field)
+            data.columns = field_names
+
+            self._source_row_count = len(data)
+            if max_rows is not None and max_rows < self._source_row_count:
+                self.data = data.slice(offset=0, length=max_rows)
+            else:
+                self.data = data
+            self._console = Console()
+            self._column_content_widths: list[int] = []
+
+        @property
+        def source_data(self) -> pl.DataFrame:
+            return self._source_data
+
+        @property
+        def source_row_count(self) -> int:
+            return self._source_row_count
+
+        @property
+        def row_count(self) -> int:
+            return len(self.data)
+
+        @property
+        def column_count(self) -> int:
+            return len(self.data.columns)
+
+        @property
+        def columns(self) -> Sequence[str]:
+            return self.data.columns
+
+        def get_row_at(self, index: int) -> Sequence[Any]:
+            if index < 0 or index >= len(self.data):
+                raise IndexError(
+                    f"Cannot get row={index} in table with {len(self.data)} rows "
+                    f"and {len(self.data.columns)} cols"
+                )
+            return list(self.data.slice(index, length=1).to_dicts()[0].values())
+
+        def get_column_at(self, column_index: int) -> Sequence[Any]:
+            if column_index < 0 or column_index >= len(self.data.columns):
+                raise IndexError(
+                    f"Cannot get column={column_index} in table with {len(self.data)} "
+                    f"rows and {len(self.data.columns)} cols."
+                )
+            return list(self.data.to_series(column_index))
+
+        def get_cell_at(self, row_index: int, column_index: int) -> Any:
+            if (
+                row_index >= len(self.data)
+                or row_index < 0
+                or column_index < 0
+                or column_index >= len(self.data.columns)
+            ):
+                raise IndexError(
+                    f"Cannot get cell at row={row_index} col={column_index} in table "
+                    f"with {len(self.data)} rows and {len(self.data.columns)} cols"
+                )
+            return self.data.to_series(column_index)[row_index]
+
+        def drop_row(self, row_index: int) -> None:
+            if row_index < 0 or row_index >= self.row_count:
+                raise IndexError(f"Can't drop row {row_index} of {self.row_count}")
+            above = self.data.slice(0, row_index)
+            below = self.data.slice(row_index + 1)
+            self.data = pl.concat([above, below])
+            self._reset_content_widths()
+
+        def append_rows(self, records: Iterable[Iterable[Any]]) -> list[int]:
+            rows_to_add = pl.from_dicts(
+                [dict(zip(self.data.columns, row)) for row in records]
+            )
+            indicies = list(range(self.row_count, self.row_count + len(rows_to_add)))
+            self.data = pl.concat([self.data, rows_to_add])
+            self._reset_content_widths()
+            return indicies
+
+        def append_column(self, label: str, default: Any | None = None) -> int:
+            """
+            Returns column index
+            """
+            self.data = self.data.with_columns(
+                pl.Series([default])
+                .extend_constant(default, self.row_count - 1)
+                .alias(label)
+            )
+            if self._column_content_widths:
+                self._column_content_widths.append(
+                    measure_width(default, self._console)
+                )
+            return len(self.data.columns) - 1
+
+        def _reset_content_widths(self) -> None:
+            self._column_content_widths = []
+
+        def update_cell(self, row_index: int, column_index: int, value: Any) -> None:
+            if row_index >= len(self.data) or column_index >= len(self.data.columns):
+                raise IndexError(
+                    f"Cannot update cell at row={row_index} col={column_index} in "
+                    f"table with {len(self.data)} rows and "
+                    f"{len(self.data.columns)} cols"
+                )
+            col_name = self.data.columns[column_index]
+            self.data = self.data.with_columns(
+                self.data.to_series(column_index)
+                .scatter(row_index, value)
+                .alias(col_name)
+            )
+            if self._column_content_widths:
+                self._column_content_widths[column_index] = max(
+                    measure_width(value, self._console),
+                    self._column_content_widths[column_index],
+                )
+
+        @property
+        def column_content_widths(self) -> list[int]:
+            if not self._column_content_widths:
+                measurements = [
+                    self._measure(self.data[arr]) for arr in self.data.columns
+                ]
+                # pc.max returns None for each column without rows; we need to return 0
+                # instead.
+                self._column_content_widths = [cw or 0 for cw in measurements]
+
+            return self._column_content_widths
+
+        def _measure(self, arr: pl.Series) -> int:
+            # with some types we can measure the width more efficiently
+            dtype = arr.dtype
+            if dtype == pld.Categorical():
+                return self._measure(arr.cat.get_categories())
+
+            if dtype.is_decimal() or dtype.is_float() or dtype.is_integer():
+                col_max = arr.max()
+                col_min = arr.min()
+                return max(
+                    [measure_width(el, self._console) for el in [col_max, col_min]]
+                )
+            if dtype.is_temporal():
+                try:
+                    value = arr.drop_nulls()[0]
+                except IndexError:
+                    return 0
+                else:
+                    return measure_width(value, self._console)
+            if dtype.is_(pld.Boolean()):
+                return 7
+
+            # for everything else, we need to compute it
+
+            arr = arr.cast(
+                pl.Utf8(),
+                strict=False,
+            )
+            width = arr.fill_null("<null>").str.len_chars().max()
+            assert isinstance(width, int)
+            return width
+
+        def sort(
+            self, by: list[tuple[str, Literal["ascending", "descending"]]] | str
+        ) -> None:
+            """
+            by: str sorts table by the data in the column with that name (asc).
+            by: list[tuple] sorts the table by the named column(s) with the directions
+                indicated.
+            """
+            if isinstance(by, str):
+                cols = [by]
+                typs = [False]
+            else:
+                cols = [x for x, _ in by]
+                typs = [x == "descending" for _, x in by]
+            self.data = self.data.sort(cols, descending=typs)
--- a/src/textual_fastdatatable/column.py
+++ b/src/textual_fastdatatable/column.py
@ -0,0 +1,47 @@
+from __future__ import annotations
+
+import re
+from dataclasses import dataclass
+
+from rich.text import Text
+
+CELL_X_PADDING = 2
+
+SNAKE_ID_PROG = re.compile(r"(\b|_)id\b", flags=re.IGNORECASE)
+CAMEL_ID_PROG = re.compile(r"[a-z]I[dD]\b")
+
+
+@dataclass
+class Column:
+    """Metadata for a column in the DataTable."""
+
+    label: Text
+    width: int = 0
+    content_width: int = 0
+    auto_width: bool = False
+    max_content_width: int | None = None
+
+    def __post_init__(self) -> None:
+        self._is_id: bool | None = None
+
+    @property
+    def render_width(self) -> int:
+        """Width in cells, required to render a column."""
+        # +2 is to account for space padding either side of the cell
+        if self.auto_width and self.max_content_width is not None:
+            return (
+                min(max(len(self.label), self.content_width), self.max_content_width)
+                + CELL_X_PADDING
+            )
+        elif self.auto_width:
+            return max(len(self.label), self.content_width) + CELL_X_PADDING
+        else:
+            return self.width + CELL_X_PADDING
+
+    @property
+    def is_id(self) -> bool:
+        if self._is_id is None:
+            snake_id = SNAKE_ID_PROG.search(str(self.label)) is not None
+            camel_id = CAMEL_ID_PROG.search(str(self.label)) is not None
+            self._is_id = snake_id or camel_id
+        return self._is_id
--- a/src/textual_fastdatatable/data_table.py
+++ b/src/textual_fastdatatable/data_table.py
--- a/src/textual_fastdatatable/formatter.py
+++ b/src/textual_fastdatatable/formatter.py
@ -0,0 +1,101 @@
+from __future__ import annotations
+
+from datetime import date, datetime, time, timedelta
+from decimal import Decimal
+from typing import cast
+
+from rich.align import Align
+from rich.console import Console, RenderableType
+from rich.errors import MarkupError
+from rich.markup import escape
+from rich.protocol import is_renderable
+from rich.text import Text
+
+from textual_fastdatatable.column import Column
+
+
+def cell_formatter(
+    obj: object, null_rep: Text, col: Column | None = None, render_markup: bool = True
+) -> RenderableType:
+    """Convert a cell into a Rich renderable for display.
+
+    For correct formatting, clients should call `locale.setlocale()` first.
+
+    Args:
+        obj: Data for a cell.
+        col: Column that the cell came from (used to compute width).
+
+    Returns:
+        A renderable to be displayed which represents the data.
+    """
+    if obj is None:
+        return Align(null_rep, align="center")
+
+    elif isinstance(obj, str) and render_markup:
+        try:
+            rich_text: Text | str = Text.from_markup(obj)
+        except MarkupError:
+            rich_text = escape(obj)
+        return rich_text
+
+    elif isinstance(obj, str):
+        return escape(obj)
+
+    elif isinstance(obj, bool):
+        return Align(
+            f"[dim]{'✓' if obj else 'X'}[/] {obj}{' ' if obj else ''}",
+            style="bold" if obj else "",
+            align="right",
+        )
+
+    elif isinstance(obj, (float, Decimal)):
+        return Align(f"{obj:n}", align="right")
+
+    elif isinstance(obj, int):
+        if col is not None and col.is_id:
+            # no separators in ID fields
+            return Align(str(obj), align="right")
+        else:
+            return Align(f"{obj:n}", align="right")
+
+    elif isinstance(obj, (datetime, time)):
+
+        def _fmt_datetime(obj: datetime | time) -> str:
+            return obj.isoformat(timespec="milliseconds").replace("+00:00", "Z")
+
+        if obj in (datetime.max, datetime.min):
+            return Align(
+                (
+                    f"[bold]{'∞ ' if obj == datetime.max else '-∞ '}[/]"
+                    f"[dim]{_fmt_datetime(obj)}[/]"
+                ),
+                align="right",
+            )
+
+        return Align(_fmt_datetime(obj), align="right")
+
+    elif isinstance(obj, date):
+        if obj in (date.max, date.min):
+            return Align(
+                (
+                    f"[bold]{'∞ ' if obj == date.max else '-∞ '}[/]"
+                    f"[dim]{obj.isoformat()}[/]"
+                ),
+                align="right",
+            )
+
+        return Align(obj.isoformat(), align="right")
+
+    elif isinstance(obj, timedelta):
+        return Align(str(obj), align="right")
+
+    elif not is_renderable(obj):
+        return str(obj)
+
+    else:
+        return cast(RenderableType, obj)
+
+
+def measure_width(obj: object, console: Console) -> int:
+    renderable = cell_formatter(obj, null_rep=Text(""))
+    return console.measure(renderable).maximum
--- a/src/textual_fastdatatable/py.typed
+++ b/src/textual_fastdatatable/py.typed
--- a/stubs/pyarrow/init.pyi
+++ b/stubs/pyarrow/init.pyi
@ -0,0 +1,166 @@
+from __future__ import annotations
+
+from typing import Any, Iterable, Iterator, Literal, Mapping, Sequence, Type, TypeVar
+
+import pandas as pd
+
+from .compute import CastOptions
+
+class DataType: ...
+class Date32Type(DataType): ...
+class Date64Type(DataType): ...
+class TimestampType(DataType): ...
+
+def string() -> DataType: ...
+def null() -> DataType: ...
+def bool_() -> DataType: ...
+def int8() -> DataType: ...
+def int16() -> DataType: ...
+def int32() -> DataType: ...
+def int64() -> DataType: ...
+def uint8() -> DataType: ...
+def uint16() -> DataType: ...
+def uint32() -> DataType: ...
+def uint64() -> DataType: ...
+def float16() -> DataType: ...
+def float32() -> DataType: ...
+def float64() -> DataType: ...
+def date32() -> DataType: ...
+def date64() -> DataType: ...
+def binary(length: int = -1) -> DataType: ...
+def large_binary() -> DataType: ...
+def large_string() -> DataType: ...
+def month_day_nano_interval() -> DataType: ...
+def time32(unit: Literal["s", "ms", "us", "ns"]) -> DataType: ...
+def time64(unit: Literal["s", "ms", "us", "ns"]) -> DataType: ...
+def timestamp(
+    unit: Literal["s", "ms", "us", "ns"], tz: str | None = None
+) -> DataType: ...
+def duration(unit: Literal["s", "ms", "us", "ns"]) -> DataType: ...
+
+class MemoryPool: ...
+class Schema: ...
+class Field: ...
+class NativeFile: ...
+class MonthDayNano: ...
+
+class Scalar:
+    def as_py(self) -> Any: ...
+    @property
+    def type(self) -> DataType: ...
+
+A = TypeVar("A", bound="_PandasConvertible")
+
+class _PandasConvertible:
+    @property
+    def type(self) -> DataType: ...  # noqa: A003
+    def cast(
+        self: A,
+        target_type: DataType | None = None,
+        safe: bool = True,
+        options: CastOptions | None = None,
+    ) -> A: ...
+    def __getitem__(self, index: int) -> Scalar: ...
+    def __iter__(self) -> Any: ...
+    def to_pylist(self) -> list[Any]: ...
+    def fill_null(self: A, fill_value: Any) -> A: ...
+    def drop_null(self: A) -> A: ...
+
+class Array(_PandasConvertible): ...
+class ChunkedArray(_PandasConvertible): ...
+
+class StructArray(Array):
+    def flatten(self, memory_pool: MemoryPool | None = None) -> list[Array]: ...
+
+T = TypeVar("T", bound="_Tabular")
+
+class _Tabular:
+    @classmethod
+    def from_arrays(
+        cls: Type[T],
+        arrays: list[_PandasConvertible],
+        names: list[str] | None = None,
+        schema: Schema | None = None,
+        metadata: Mapping | None = None,
+    ) -> T: ...
+    @classmethod
+    def from_pydict(
+        cls: Type[T],
+        mapping: Mapping,
+        schema: Schema | None = None,
+        metadata: Mapping | None = None,
+    ) -> T: ...
+    def __getitem__(self, index: int) -> _PandasConvertible: ...
+    def __len__(self) -> int: ...
+    @property
+    def column_names(self) -> list[str]: ...
+    @property
+    def columns(self) -> list[_PandasConvertible]: ...
+    @property
+    def num_rows(self) -> int: ...
+    @property
+    def num_columns(self) -> int: ...
+    @property
+    def schema(self) -> Schema: ...
+    def append_column(
+        self: T, field_: str | Field, column: Array | ChunkedArray
+    ) -> T: ...
+    def column(self, i: int | str) -> _PandasConvertible: ...
+    def equals(self: T, other: T, check_metadata: bool = False) -> bool: ...
+    def itercolumns(self) -> Iterator[_PandasConvertible]: ...
+    def rename_columns(self: T, names: list[str]) -> T: ...
+    def select(self: T, columns: Sequence[str | int]) -> T: ...
+    def set_column(
+        self: T, i: int, field_: str | Field, column: Array | ChunkedArray
+    ) -> T: ...
+    def slice(  # noqa: A003
+        self: T,
+        offset: int = 0,
+        length: int | None = None,
+    ) -> T: ...
+    def sort_by(
+        self: T,
+        sorting: str | list[tuple[str, Literal["ascending", "descending"]]],
+        **kwargs: Any,
+    ) -> T: ...
+    def to_pylist(self) -> list[dict[str, Any]]: ...
+
+class RecordBatch(_Tabular): ...
+
+class Table(_Tabular):
+    @classmethod
+    def from_batches(
+        cls,
+        batches: Iterable[RecordBatch],
+        schema: Schema | None = None,
+    ) -> "Table": ...
+    def to_batches(self) -> list[RecordBatch]: ...
+
+def scalar(value: Any, type: DataType) -> Scalar: ...  # noqa: A002
+def array(
+    obj: Iterable,
+    type: DataType | None = None,  # noqa: A002
+    mask: Array | None = None,
+    size: int | None = None,
+    from_pandas: bool | None = None,
+    safe: bool = True,
+    memory_pool: MemoryPool | None = None,
+) -> Array | ChunkedArray: ...
+def concat_arrays(
+    arrays: Iterable[Array], memory_pool: MemoryPool | None = None
+) -> Array: ...
+def nulls(
+    size: int,
+    type: DataType | None = None,  # noqa: A002
+    memory_pool: MemoryPool | None = None,
+) -> Array: ...
+def table(
+    data: pd.DataFrame
+    | Mapping[str, _PandasConvertible | list]
+    | list[_PandasConvertible],
+    names: list[str] | None = None,
+    schema: Schema | None = None,
+    metadata: Mapping | None = None,
+    nthreads: int | None = None,
+) -> Table: ...
+def set_timezone_db_path(path: str) -> None: ...
--- a/stubs/pyarrow/compute.pyi
+++ b/stubs/pyarrow/compute.pyi
@ -0,0 +1,64 @@
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Any, Callable, Literal
+
+from . import DataType, MemoryPool, Scalar, _PandasConvertible
+
+class Expression: ...
+class ScalarAggregateOptions: ...
+
+class CastOptions:
+    def __init__(
+        self,
+        target_type: DataType | None = None,
+        allow_int_overflow: bool | None = None,
+        allow_time_truncate: bool | None = None,
+        allow_time_overflow: bool | None = None,
+        allow_decimal_truncate: bool | None = None,
+        allow_float_truncate: bool | None = None,
+        allow_invalid_utf8: bool | None = None,
+    ) -> None: ...
+
+def max(  # noqa: A001
+    array: _PandasConvertible,
+    /,
+    *,
+    skip_nulls: bool = True,
+    min_count: int = 1,
+    options: ScalarAggregateOptions | None = None,
+    memory_pool: MemoryPool | None = None,
+) -> Scalar: ...
+def min(  # noqa: A001
+    array: _PandasConvertible,
+    /,
+    *,
+    skip_nulls: bool = True,
+    min_count: int = 1,
+    options: ScalarAggregateOptions | None = None,
+    memory_pool: MemoryPool | None = None,
+) -> Scalar: ...
+def utf8_length(
+    strings: _PandasConvertible, /, *, memory_pool: MemoryPool | None = None
+) -> _PandasConvertible: ...
+def register_scalar_function(
+    func: Callable,
+    function_name: str,
+    function_doc: dict[Literal["summary", "description"], str],
+    in_types: dict[str, DataType],
+    out_type: DataType,
+    func_registry: Any | None = None,
+) -> None: ...
+def call_function(
+    function_name: str, target: list[_PandasConvertible]
+) -> _PandasConvertible: ...
+def assume_timezone(
+    timestamps: _PandasConvertible | Scalar | datetime,
+    /,
+    timezone: str,
+    *,
+    ambiguous: Literal["raise", "earliest", "latest"] = "raise",
+    nonexistent: Literal["raise", "earliest", "latest"] = "raise",
+    options: Any | None = None,
+    memory_pool: MemoryPool | None = None,
+) -> _PandasConvertible: ...
--- a/stubs/pyarrow/dataset.pyi
+++ b/stubs/pyarrow/dataset.pyi
@ -0,0 +1 @@
+class Partitioning: ...
--- a/stubs/pyarrow/fs.pyi
+++ b/stubs/pyarrow/fs.pyi
@ -0,0 +1 @@
+class FileSystem: ...
--- a/stubs/pyarrow/lib.pyi
+++ b/stubs/pyarrow/lib.pyi
@ -0,0 +1,32 @@
+from . import Date32Type, Date64Type, Scalar, TimestampType
+
+class ArrowException(Exception): ...
+class ArrowInvalid(ValueError, ArrowException): ...
+class ArrowMemoryError(MemoryError, ArrowException): ...
+class ArrowKeyError(KeyError, Exception): ...
+class ArrowTypeError(TypeError, Exception): ...
+class ArrowNotImplementedError(NotImplementedError, ArrowException): ...
+class ArrowCapacityError(ArrowException): ...
+class ArrowIndexError(IndexError, ArrowException): ...
+class ArrowSerializationError(ArrowException): ...
+class ArrowCancelled(ArrowException): ...
+
+ArrowIOError = IOError
+
+class Date32Scalar(Scalar):
+    @property
+    def type(self) -> Date32Type: ...
+    @property
+    def value(self) -> int: ...
+
+class Date64Scalar(Scalar):
+    @property
+    def type(self) -> Date64Type: ...
+    @property
+    def value(self) -> int: ...
+
+class TimestampScalar(Scalar):
+    @property
+    def type(self) -> TimestampType: ...
+    @property
+    def value(self) -> int: ...
--- a/stubs/pyarrow/parquet.pyi
+++ b/stubs/pyarrow/parquet.pyi
@ -0,0 +1,60 @@
+from __future__ import annotations
+
+from typing import Any, BinaryIO, Literal
+
+from . import NativeFile, Schema, Table
+from .compute import Expression
+from .dataset import Partitioning
+from .fs import FileSystem
+
+class FileMetaData: ...
+
+def read_table(
+    source: str | NativeFile | BinaryIO,
+    *,
+    columns: list | None = None,
+    use_threads: bool = True,
+    metadata: FileMetaData | None = None,
+    schema: Schema | None = None,
+    use_pandas_metadata: bool = False,
+    read_dictionary: list | None = None,
+    memory_map: bool = False,
+    buffer_size: int = 0,
+    partitioning: Partitioning | str | list[str] = "hive",
+    filesystem: FileSystem | None = None,
+    filters: Expression | list[tuple] | list[list[tuple]] | None = None,
+    use_legacy_dataset: bool = False,
+    ignore_prefixes: list | None = None,
+    pre_buffer: bool = True,
+    coerce_int96_timestamp_unit: str | None = None,
+    decryption_properties: Any | None = None,
+    thrift_string_size_limit: int | None = None,
+    thrift_container_size_limit: int | None = None,
+) -> Table: ...
+def write_table(
+    table: Table,
+    where: str | NativeFile,
+    row_group_size: int | None = None,
+    version: Literal["1.0", "2.4", "2.6"] = "2.6",
+    use_dictionary: bool | list = True,
+    compression: Literal["none", "snappy", "gzip", "brotli", "lz4", "zstd"]
+    | dict[str, Literal["none", "snappy", "gzip", "brotli", "lz4", "zstd"]] = "snappy",
+    write_statistics: bool | list = True,
+    use_deprecated_int96_timestamps: bool | None = None,
+    coerce_timestamps: str | None = None,
+    allow_truncated_timestamps: bool = False,
+    data_page_size: int | None = None,
+    flavor: Literal["spark"] | None = None,
+    filesystem: FileSystem | None = None,
+    compression_level: int | dict | None = None,
+    use_byte_stream_split: bool | list = False,
+    column_encoding: str | dict | None = None,
+    data_page_version: Literal["1.0", "2.0"] = "1.0",
+    use_compliant_nested_type: bool = True,
+    encryption_properties: Any | None = None,
+    write_batch_size: int | None = None,
+    dictionary_pagesize_limit: int | None = None,
+    store_schema: bool = True,
+    write_page_index: bool = False,
+    **kwargs: Any,
+) -> None: ...
--- a/stubs/pyarrow/types.pyi
+++ b/stubs/pyarrow/types.pyi
@ -0,0 +1,27 @@
+from __future__ import annotations
+
+from . import DataType, Date32Type, Date64Type, TimestampType
+
+def is_null(t: DataType) -> bool: ...
+def is_struct(t: DataType) -> bool: ...
+def is_boolean(t: DataType) -> bool: ...
+def is_integer(t: DataType) -> bool: ...
+def is_floating(t: DataType) -> bool: ...
+def is_decimal(t: DataType) -> bool: ...
+def is_temporal(t: DataType) -> bool: ...
+def is_date(t: DataType) -> bool: ...
+def is_date32(t: DataType) -> bool:
+    if isinstance(t, Date32Type):
+        return True
+    return False
+
+def is_date64(t: DataType) -> bool:
+    if isinstance(t, Date64Type):
+        return True
+    return False
+
+def is_time(t: DataType) -> bool: ...
+def is_timestamp(t: DataType) -> bool:
+    if isinstance(t, TimestampType):
+        return True
+    return False
--- a/tests/conftest.py
+++ b/tests/conftest.py
@ -0,0 +1,34 @@
+from __future__ import annotations
+
+from typing import Sequence, Type
+
+import pytest
+from textual_fastdatatable.backend import ArrowBackend, DataTableBackend, PolarsBackend
+
+
+@pytest.fixture
+def pydict() -> dict[str, Sequence[str | int]]:
+    return {
+        "first column": [1, 2, 3, 4, 5],
+        "two": ["a", "b", "c", "d", "asdfasdf"],
+        "three": ["foo", "bar", "baz", "qux", "foofoo"],
+    }
+
+
+@pytest.fixture
+def records(pydict: dict[str, Sequence[str | int]]) -> list[tuple[str | int, ...]]:
+    header = tuple(pydict.keys())
+    cols = list(pydict.values())
+    num_rows = len(cols[0])
+    data = [tuple([col[i] for col in cols]) for i in range(num_rows)]
+    return [header, *data]
+
+
+@pytest.fixture(params=[ArrowBackend, PolarsBackend])
+def backend(
+    request: Type[pytest.FixtureRequest], pydict: dict[str, Sequence[str | int]]
+) -> DataTableBackend:
+    backend_cls = request.param
+    assert issubclass(backend_cls, (ArrowBackend, PolarsBackend))
+    backend: ArrowBackend | PolarsBackend = backend_cls.from_pydict(pydict)
+    return backend
--- a/tests/data/lap_times_100.parquet
+++ b/tests/data/lap_times_100.parquet
--- a/tests/data/lap_times_1000.parquet
+++ b/tests/data/lap_times_1000.parquet
--- a/tests/data/lap_times_10000.parquet
+++ b/tests/data/lap_times_10000.parquet
--- a/tests/data/lap_times_100000.parquet
+++ b/tests/data/lap_times_100000.parquet
--- a/tests/data/lap_times_538121.parquet
+++ b/tests/data/lap_times_538121.parquet
--- a/tests/data/wide_10000.parquet
+++ b/tests/data/wide_10000.parquet
--- a/tests/data/wide_100000.parquet
+++ b/tests/data/wide_100000.parquet
--- a/tests/snapshot_tests/LICENSE
+++ b/tests/snapshot_tests/LICENSE
@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Will McGugan
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
--- a/tests/snapshot_tests/snapshots/test_snapshots.ambr
+++ b/tests/snapshot_tests/snapshots/test_snapshots.ambr
--- a/tests/snapshot_tests/_snapshots_backup/test_snapshots.ambr
+++ b/tests/snapshot_tests/_snapshots_backup/test_snapshots.ambr
--- a/tests/snapshot_tests/snapshot_apps/auto-table.py
+++ b/tests/snapshot_tests/snapshot_apps/auto-table.py
@ -0,0 +1,185 @@
+from textual.app import App
+from textual.containers import Container, Horizontal, ScrollableContainer, Vertical
+from textual.screen import Screen
+from textual.widgets import Header, Label
+from textual_fastdatatable import ArrowBackend, DataTable
+
+
+class LabeledBox(Container):
+    DEFAULT_CSS = """
+    LabeledBox {
+        layers: base_ top_;
+        width: 100%;
+        height: 100%;
+    }
+
+    LabeledBox > Container {
+        layer: base_;
+        border: round $primary;
+        width: 100%;
+        height: 100%;
+        layout: vertical;
+    }
+
+    LabeledBox > Label {
+        layer: top_;
+        offset-x: 2;
+    }
+    """
+
+    def __init__(self, title, *args, **kwargs):
+        self.__label = Label(title)
+
+        super().__init__(self.__label, Container(*args, **kwargs))
+
+    @property
+    def label(self):
+        return self.__label
+
+
+class StatusTable(DataTable):
+    def __init__(self) -> None:
+        backend = ArrowBackend.from_pydict(
+            {
+                "Foo": ["ABCDEFGH"] * 50,
+                "Bar": ["0123456789"] * 50,
+                "Baz": ["IJKLMNOPQRSTUVWXYZ"] * 50,
+            }
+        )
+        super().__init__(backend=backend)
+
+        self.cursor_type = "row"
+        self.show_cursor = False
+
+
+class Status(LabeledBox):
+    DEFAULT_CSS = """
+    Status {
+        width: auto;
+    }
+
+    Status Container {
+        width: auto;
+    }
+
+    Status StatusTable {
+        width: auto;
+        height: 100%;
+        margin-top: 1;
+        scrollbar-gutter: stable;
+        overflow-x: hidden;
+    }
+    """
+
+    def __init__(self, name: str):
+        self.__name = name
+        self.__table = StatusTable()
+
+        super().__init__(f" {self.__name} ", self.__table)
+
+    @property
+    def name(self) -> str:
+        return self.__name
+
+    @property
+    def table(self) -> StatusTable:
+        return self.__table
+
+
+class Rendering(LabeledBox):
+    DEFAULT_CSS = """
+    #issue-info {
+        height: auto;
+        border-bottom: dashed #632CA6;
+    }
+
+    #statuses-box {
+        height: 1fr;
+        width: auto;
+    }
+    """
+
+    def __init__(self):
+        self.__info = Label("test")
+
+        super().__init__(
+            "",
+            ScrollableContainer(
+                Horizontal(self.__info, id="issue-info"),
+                Horizontal(*[Status(str(i)) for i in range(4)], id="statuses-box"),
+                id="issues-box",
+            ),
+        )
+
+    @property
+    def info(self) -> Label:
+        return self.__info
+
+
+class Sidebar(LabeledBox):
+    DEFAULT_CSS = """
+    #sidebar-status {
+        height: auto;
+        border-bottom: dashed #632CA6;
+    }
+
+    #sidebar-options {
+        height: 1fr;
+    }
+    """
+
+    def __init__(self):
+        self.__status = Label("ok")
+        self.__options = Vertical()
+
+        super().__init__(
+            "",
+            Container(self.__status, id="sidebar-status"),
+            Container(self.__options, id="sidebar-options"),
+        )
+
+    @property
+    def status(self) -> Label:
+        return self.__status
+
+    @property
+    def options(self) -> Vertical:
+        return self.__options
+
+
+class MyScreen(Screen):
+    DEFAULT_CSS = """
+    #main-content {
+        layout: grid;
+        grid-size: 2;
+        grid-columns: 1fr 5fr;
+        grid-rows: 1fr;
+    }
+
+    #main-content-sidebar {
+        height: 100%;
+    }
+
+    #main-content-rendering {
+        height: 100%;
+    }
+    """
+
+    def compose(self):
+        yield Header()
+        yield Container(
+            Container(Sidebar(), id="main-content-sidebar"),
+            Container(Rendering(), id="main-content-rendering"),
+            id="main-content",
+        )
+
+
+class MyApp(App):
+    async def on_mount(self):
+        self.install_screen(MyScreen(), "myscreen")
+        await self.push_screen("myscreen")
+
+
+if __name__ == "__main__":
+    app = MyApp()
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table.py
@ -0,0 +1,26 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+ROWS = [
+    ("lane", "swimmer", "country", "time"),
+    (4, "Joseph Schooling", "Singapore", 50.39),
+    (2, "Michael Phelps", "United States", 51.14),
+    (5, "Chad le Clos", "South Africa", 51.14),
+    (6, "László Cseh", "Hungary", 51.14),
+    (3, "Li Zhuhao", "China", 51.26),
+    (8, "Mehdy Metella", "France", 51.58),
+    (7, "Tom Shields", "United States", 51.73),
+    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
+    (10, "Darren Burns", "Scotland", 51.84),
+]
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        backend = ArrowBackend.from_records(ROWS, has_header=True)
+        yield DataTable(backend=backend)
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_add_column.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_add_column.py
@ -0,0 +1,36 @@
+from textual.app import App, ComposeResult
+from textual.binding import Binding
+from textual_fastdatatable import ArrowBackend, DataTable
+
+MOVIES = [
+    "Severance",
+    "Foundation",
+    "Dark",
+    "The Boys",
+    "The Last of Us",
+    "Lost in Space",
+    "Altered Carbon",
+]
+
+
+class AddColumn(App):
+    BINDINGS = [
+        Binding(key="c", action="add_column", description="Add Column"),
+    ]
+
+    def compose(self) -> ComposeResult:
+        backend = ArrowBackend.from_pydict({"Movies": MOVIES})
+        table = DataTable(backend=backend)
+
+        column_idx = table.add_column("No Default")
+        table.add_column("With Default", default="ABC")
+        table.add_column("Long Default", default="01234567890123456789")
+
+        # Ensure we can update a cell
+        table.update_cell(2, column_idx, "Hello!")
+        yield table
+
+
+app = AddColumn()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_add_row_auto_height.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_add_row_auto_height.py
@ -0,0 +1,24 @@
+from rich.panel import Panel
+from rich.text import Text
+from textual.app import App
+from textual_fastdatatable import DataTable
+
+
+class AutoHeightRowsApp(App[None]):
+    def compose(self):
+        table = DataTable()
+        self.column = table.add_column("N")
+        table.add_column("Column", width=10)
+        table.add_row(3, "hey there", height=None)
+        table.add_row(1, Text("hey there"), height=None)
+        table.add_row(5, Text("long string", overflow="fold"), height=None)
+        table.add_row(2, Panel.fit("Hello\nworld"), height=None)
+        table.add_row(4, "1\n2\n3\n4\n5\n6\n7", height=None)
+        yield table
+
+    def key_s(self):
+        self.query_one(DataTable).sort(self.column)
+
+
+if __name__ == "__main__":
+    AutoHeightRowsApp().run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_column_cursor.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_column_cursor.py
@ -0,0 +1,35 @@
+import csv
+import io
+
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+CSV = """lane,swimmer,country,time
+4,Joseph Schooling,Singapore,50.39
+2,Michael Phelps,United States,51.14
+5,Chad le Clos,South Africa,51.14
+6,László Cseh,Hungary,51.14
+3,Li Zhuhao,China,51.26
+8,Mehdy Metella,France,51.58
+7,Tom Shields,United States,51.73
+1,Aleksandr Sadovnikov,Russia,51.84"""
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        rows = csv.reader(io.StringIO(CSV))
+        labels = next(rows)
+        data = [row for row in rows]
+        backend = ArrowBackend.from_pydict(
+            {label: [row[i] for row in data] for i, label in enumerate(labels)}
+        )
+        table = DataTable(
+            backend=backend, cursor_type="column", fixed_columns=1, fixed_rows=1
+        )
+        table.focus()
+        yield table
+
+
+if __name__ == "__main__":
+    app = TableApp()
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_max_width.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_max_width.py
@ -0,0 +1,35 @@
+import csv
+import io
+
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+CSV = """lane,swimmer,country,time
+4,Joseph Schooling,Singapore,50.39
+2,Michael Phelps,United States,51.14
+5,Chad le Clos,South Africa,51.14
+6,László Cseh,Hungary,51.14
+3,Li Zhuhao,China,51.26
+8,Mehdy Metella,France,51.58
+7,Tom Shields,United States,51.73
+1,Aleksandr Sadovnikov,Russia,51.84"""
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        rows = csv.reader(io.StringIO(CSV))
+        labels = next(rows)
+        data = [row for row in rows]
+        backend = ArrowBackend.from_pydict(
+            {label: [row[i] for row in data] for i, label in enumerate(labels)}
+        )
+        table = DataTable(
+            backend=backend, cursor_type="range", max_column_content_width=8
+        )
+        table.focus()
+        yield table
+
+
+if __name__ == "__main__":
+    app = TableApp()
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_no_render_markup.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_no_render_markup.py
@ -0,0 +1,26 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+ROWS = [
+    ("lane", "swimmer", "country", "time"),
+    (4, "[Joseph Schooling]", "Singapore", 50.39),
+    (2, "[red]Michael Phelps[/]", "United States", 51.14),
+    (5, "[bold]Chad le Clos[/]", "South Africa", 51.14),
+    (6, "László Cseh", "Hungary", 51.14),
+    (3, "Li Zhuhao", "China", 51.26),
+    (8, "Mehdy Metella", "France", 51.58),
+    (7, "Tom Shields", "United States", 51.73),
+    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
+    (10, "Darren Burns", "Scotland", 51.84),
+]
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        backend = ArrowBackend.from_records(ROWS, has_header=True)
+        yield DataTable(backend=backend, render_markup=False)
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_null_mixed_cols.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_null_mixed_cols.py
@ -0,0 +1,22 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+ROWS = [
+    ("lane", "swimmer", "country", "time"),
+    (3, "Li Zhuhao", "China", 51.26),
+    ("eight", None, "France", 51.58),
+    ("seven", "Tom Shields", "United States", None),
+    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
+    (None, "Darren Burns", "Scotland", 51.84),
+]
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        backend = ArrowBackend.from_records(ROWS, has_header=True)
+        yield DataTable(backend=backend, null_rep="[dim]∅ null[/]")
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_range_cursor.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_range_cursor.py
@ -0,0 +1,33 @@
+import csv
+import io
+
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+CSV = """lane,swimmer,country,time
+4,Joseph Schooling,Singapore,50.39
+2,Michael Phelps,United States,51.14
+5,Chad le Clos,South Africa,51.14
+6,László Cseh,Hungary,51.14
+3,Li Zhuhao,China,51.26
+8,Mehdy Metella,France,51.58
+7,Tom Shields,United States,51.73
+1,Aleksandr Sadovnikov,Russia,51.84"""
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        rows = csv.reader(io.StringIO(CSV))
+        labels = next(rows)
+        data = [row for row in rows]
+        backend = ArrowBackend.from_pydict(
+            {label: [row[i] for row in data] for i, label in enumerate(labels)}
+        )
+        table = DataTable(backend=backend, cursor_type="range")
+        table.focus()
+        yield table
+
+
+if __name__ == "__main__":
+    app = TableApp()
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_remove_row.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_remove_row.py
@ -0,0 +1,45 @@
+from textual.app import App, ComposeResult
+from textual.binding import Binding
+from textual_fastdatatable import ArrowBackend, DataTable
+
+ROWS = [
+    ("lane", "swimmer", "country", "time"),
+    (5, "Chad le Clos", "South Africa", 51.14),
+    (4, "Joseph Schooling", "Singapore", 50.39),
+    (2, "Michael Phelps", "United States", 51.14),
+    (6, "László Cseh", "Hungary", 51.14),
+    (3, "Li Zhuhao", "China", 51.26),
+    (8, "Mehdy Metella", "France", 51.58),
+    (7, "Tom Shields", "United States", 51.73),
+    (10, "Darren Burns", "Scotland", 51.84),
+    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
+]
+
+
+class TableApp(App):
+    """Snapshot app for testing removal of rows.
+    Removes several rows, so we can check that the display of the
+    DataTable updates as expected."""
+
+    BINDINGS = [
+        Binding("r", "remove_row", "Remove Row"),
+    ]
+
+    def compose(self) -> ComposeResult:
+        backend = ArrowBackend.from_records(ROWS, has_header=True)
+        yield DataTable(backend=backend)
+
+    def on_mount(self) -> None:
+        table = self.query_one(DataTable)
+        table.focus()
+
+    def action_remove_row(self):
+        table = self.query_one(DataTable)
+        table.remove_row(2)
+        table.remove_row(4)
+        table.remove_row(6)
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_row_cursor.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_row_cursor.py
@ -0,0 +1,36 @@
+import csv
+import io
+
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+CSV = """lane,swimmer,country,time
+4,Joseph Schooling,Singapore,50.39
+2,Michael Phelps,United States,51.14
+5,Chad le Clos,South Africa,51.14
+6,László Cseh,Hungary,51.14
+3,Li Zhuhao,China,51.26
+8,Mehdy Metella,France,51.58
+7,Tom Shields,United States,51.73
+1,Aleksandr Sadovnikov,Russia,51.84"""
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        rows = csv.reader(io.StringIO(CSV))
+        labels = next(rows)
+        data = [row for row in rows]
+        backend = ArrowBackend.from_pydict(
+            {label: [row[i] for row in data] for i, label in enumerate(labels)}
+        )
+        table = DataTable(backend=backend)
+        table.focus()
+        table.cursor_type = "row"
+        table.fixed_columns = 1
+        table.fixed_rows = 1
+        yield table
+
+
+if __name__ == "__main__":
+    app = TableApp()
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_row_labels.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_row_labels.py
@ -0,0 +1,37 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import DataTable
+
+ROWS = [
+    ("lane", "swimmer", "country", "time"),
+    (5, "Chad le Clos", "South Africa", 51.14),
+    (4, "Joseph Schooling", "Singapore", 50.39),
+    (2, "Michael Phelps", "United States", 51.14),
+    (6, "László Cseh", "Hungary", 51.14),
+    (3, "Li Zhuhao", "China", 51.26),
+    (8, "Mehdy Metella", "France", 51.58),
+    (7, "Tom Shields", "United States", 51.73),
+    (10, "Darren Burns", "Scotland", 51.84),
+    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
+]
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable()
+
+    def on_mount(self) -> None:
+        table = self.query_one(DataTable)
+        table.fixed_rows = 1
+        table.fixed_columns = 1
+        table.focus()
+        rows = iter(ROWS)
+        column_labels = next(rows)
+        for column in column_labels:
+            table.add_column(column, key=column)
+        for index, row in enumerate(rows):
+            table.add_row(*row, label=str(index))
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_sort.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_sort.py
@ -0,0 +1,40 @@
+from textual.app import App, ComposeResult
+from textual.binding import Binding
+from textual_fastdatatable import ArrowBackend, DataTable
+
+# Shuffled around a bit to exercise sorting.
+ROWS = [
+    ("lane", "swimmer", "country", "time"),
+    (5, "Chad le Clos", "South Africa", 51.14),
+    (4, "Joseph Schooling", "Singapore", 50.39),
+    (2, "Michael Phelps", "United States", 51.14),
+    (6, "László Cseh", "Hungary", 51.14),
+    (3, "Li Zhuhao", "China", 51.26),
+    (8, "Mehdy Metella", "France", 51.58),
+    (7, "Tom Shields", "United States", 51.73),
+    (10, "Darren Burns", "Scotland", 51.84),
+    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
+]
+
+
+class TableApp(App):
+    BINDINGS = [
+        Binding("s", "sort", "Sort"),
+    ]
+
+    def compose(self) -> ComposeResult:
+        backend = ArrowBackend.from_records(ROWS, has_header=True)
+        yield DataTable(backend=backend)
+
+    def on_mount(self) -> None:
+        table = self.query_one(DataTable)
+        table.focus()
+
+    def action_sort(self):
+        table = self.query_one(DataTable)
+        table.sort([("time", "ascending"), ("lane", "ascending")])
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/data_table_style_order.py
+++ b/tests/snapshot_tests/snapshot_apps/data_table_style_order.py
@ -0,0 +1,65 @@
+from __future__ import annotations
+
+from textual.app import App, ComposeResult
+from textual.widgets import Label
+from textual_fastdatatable import ArrowBackend, DataTable
+from typing_extensions import Literal
+
+data = [
+    "Severance",
+    "Foundation",
+    "Dark",
+]
+
+
+def make_datatable(
+    foreground_priority: Literal["css", "renderable"],
+    background_priority: Literal["css", "renderable"],
+) -> DataTable:
+    backend = ArrowBackend.from_pydict(
+        {"Movies": [f"[red on blue]{row}" for row in data]}
+    )
+    table = DataTable(
+        backend=backend,
+        cursor_foreground_priority=foreground_priority,
+        cursor_background_priority=background_priority,
+    )
+    table.zebra_stripes = True
+    return table
+
+
+class DataTableCursorStyles(App):
+    """Regression test snapshot app which ensures that styles
+    are layered on top of each other correctly in the DataTable.
+    In this example, the colour of the text in the cells under
+    the cursor should not be red, because the CSS should be applied
+    on top."""
+
+    CSS = """
+    DataTable {margin-bottom: 1;}
+    DataTable > .datatable--cursor {
+        color: $secondary;
+        background: $success;
+        text-style: bold italic;
+    }
+"""
+
+    def compose(self) -> ComposeResult:
+        priorities: list[
+            tuple[Literal["css", "renderable"], Literal["css", "renderable"]]
+        ] = [
+            ("css", "css"),
+            ("css", "renderable"),
+            ("renderable", "renderable"),
+            ("renderable", "css"),
+        ]
+        for foreground, background in priorities:
+            yield Label(f"Foreground is {foreground!r}, background is {background!r}:")
+            table = make_datatable(foreground, background)
+            yield table
+
+
+app = DataTableCursorStyles()
+
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/datatable_hot_reloading.py
+++ b/tests/snapshot_tests/snapshot_apps/datatable_hot_reloading.py
@ -0,0 +1,58 @@
+from pathlib import Path
+
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+CSS_PATH = (Path(__file__) / "../datatable_hot_reloading.tcss").resolve()
+
+# Write some CSS to the file before the app loads.
+# Then, the test will clear all the CSS to see if the
+# hot reloading applies the changes correctly.
+CSS_PATH.write_text(
+    """\
+DataTable > .datatable--cursor {
+    background: purple;
+}
+
+DataTable > .datatable--fixed {
+    background: red;
+}
+
+DataTable > .datatable--fixed-cursor {
+    background: blue;
+}
+
+DataTable > .datatable--header {
+    background: yellow;
+}
+
+DataTable > .datatable--odd-row {
+    background: pink;
+}
+
+DataTable > .datatable--even-row {
+    background: brown;
+}
+"""
+)
+
+
+class DataTableHotReloadingApp(App[None]):
+    CSS_PATH = CSS_PATH
+
+    def compose(self) -> ComposeResult:
+        data = {
+            # orig test set A width=10, we fake it with spaces
+            "A         ": ["one", "three", "five"],
+            "B": ["two", "four", "six"],
+        }
+        backend = ArrowBackend.from_pydict(data)
+        yield DataTable(backend, zebra_stripes=True, cursor_type="row", fixed_columns=1)
+
+    def on_mount(self) -> None:
+        self.query_one(DataTable)
+
+
+if __name__ == "__main__":
+    app = DataTableHotReloadingApp()
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/datatable_hot_reloading.tcss
+++ b/tests/snapshot_tests/snapshot_apps/datatable_hot_reloading.tcss
@ -0,0 +1 @@
+/* This file is purposefully empty. */
--- a/tests/snapshot_tests/snapshot_apps/empty.py
+++ b/tests/snapshot_tests/snapshot_apps/empty.py
@ -0,0 +1,12 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import DataTable
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable()
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/empty_add_col.py
+++ b/tests/snapshot_tests/snapshot_apps/empty_add_col.py
@ -0,0 +1,17 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import DataTable
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable()
+
+    def on_mount(self) -> None:
+        table = self.query_one(DataTable)
+        table.add_column("Foo")
+        table.add_rows([("1",), ("2",)])
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/from_parquet.py
+++ b/tests/snapshot_tests/snapshot_apps/from_parquet.py
@ -0,0 +1,16 @@
+from pathlib import Path
+
+from textual.app import App, ComposeResult
+from textual_fastdatatable import DataTable
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable(
+            data=Path(__file__).parent.parent.parent / "data" / "lap_times_100.parquet"
+        )
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/from_pydict_with_col_labels.py
+++ b/tests/snapshot_tests/snapshot_apps/from_pydict_with_col_labels.py
@ -0,0 +1,20 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import DataTable
+
+DATA = {
+    "Foo": list(range(50)),
+    "Bar": ["0123456789"] * 50,
+    "Baz": ["IJKLMNOPQRSTUVWXYZ"] * 50,
+}
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable(
+            data=DATA, column_labels=["[red]Not Foo[/red]", "Zig", "[reverse]Zag[/]"]
+        )
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/from_records.py
+++ b/tests/snapshot_tests/snapshot_apps/from_records.py
@ -0,0 +1,25 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import DataTable
+
+ROWS = [
+    ("lane", "swimmer", "country", "time"),
+    (4, "Joseph Schooling", "Singapore", 50.39),
+    (2, "Michael Phelps", "United States", 51.14),
+    (5, "Chad le Clos", "South Africa", 51.14),
+    (6, "László Cseh", "Hungary", 51.14),
+    (3, "Li Zhuhao", "China", 51.26),
+    (8, "Mehdy Metella", "France", 51.58),
+    (7, "Tom Shields", "United States", 51.73),
+    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
+    (10, "Darren Burns", "Scotland", 51.84),
+]
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable(data=ROWS)
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/no_rows.py
+++ b/tests/snapshot_tests/snapshot_apps/no_rows.py
@ -0,0 +1,12 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import DataTable
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable(column_labels=["foo [red]foo[/red]", "bar"])
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/snapshot_apps/no_rows_empty_sequence.py
+++ b/tests/snapshot_tests/snapshot_apps/no_rows_empty_sequence.py
@ -0,0 +1,12 @@
+from textual.app import App, ComposeResult
+from textual_fastdatatable import DataTable
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable(column_labels=["foo [red]foo[/red]", "bar"])
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()
--- a/tests/snapshot_tests/test_snapshots.py
+++ b/tests/snapshot_tests/test_snapshots.py
@ -0,0 +1,119 @@
+from pathlib import Path
+from typing import Callable
+
+import pytest
+
+# These paths should be relative to THIS directory.
+SNAPSHOT_APPS_DIR = Path("./snapshot_apps")
+
+
+def test_auto_table(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "auto-table.py", terminal_size=(120, 40))
+
+
+def test_datatable_render(snap_compare: Callable) -> None:
+    press = ["down", "down", "right", "up", "left"]
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table.py", press=press)
+
+
+def test_datatable_row_cursor_render(snap_compare: Callable) -> None:
+    press = ["up", "left", "right", "down", "down"]
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_row_cursor.py", press=press)
+
+
+def test_datatable_no_render_markup(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_no_render_markup.py")
+
+
+def test_datatable_null_mixed_cols(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_null_mixed_cols.py")
+
+
+def test_datatable_range_cursor_render(snap_compare: Callable) -> None:
+    press = ["right", "down", "shift+right", "shift+down", "shift+down"]
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_range_cursor.py", press=press)
+
+
+def test_datatable_column_cursor_render(snap_compare: Callable) -> None:
+    press = ["left", "up", "down", "right", "right"]
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_column_cursor.py", press=press)
+
+
+def test_datatable_max_width_render(snap_compare: Callable) -> None:
+    press = ["right", "down", "shift+right", "shift+down", "shift+down"]
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_max_width.py", press=press)
+
+
+def test_datatable_sort_multikey(snap_compare: Callable) -> None:
+    press = ["down", "right", "s"]  # Also checks that sort doesn't move cursor.
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_sort.py", press=press)
+
+
+def test_datatable_remove_row(snap_compare: Callable) -> None:
+    press = ["r"]
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_remove_row.py", press=press)
+
+
+@pytest.mark.skip(reason="Don't support row labels.")
+def test_datatable_labels_and_fixed_data(snap_compare: Callable) -> None:
+    # Ensure that we render correctly when there are fixed rows/cols and labels.
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_row_labels.py")
+
+
+# skip, don't xfail; see: https://github.com/Textualize/pytest-textual-snapshot/issues/6
+@pytest.mark.skip(
+    reason=(
+        "The data in this test includes markup; the backend doesn't"
+        "know these have zero width, so we draw the column wider than we used to"
+    )
+)
+def test_datatable_style_ordering(snap_compare: Callable) -> None:
+    # Regression test for https -> None://github.com/Textualize/textual/issues/2061
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_style_order.py")
+
+
+def test_datatable_add_column(snap_compare: Callable) -> None:
+    # Checking adding columns after adding rows
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_add_column.py")
+
+
+@pytest.mark.skip(reason="No multi-height rows. No Rich objects.")
+def test_datatable_add_row_auto_height(snap_compare: Callable) -> None:
+    # Check that rows added with auto height computation look right.
+    assert snap_compare(SNAPSHOT_APPS_DIR / "data_table_add_row_auto_height.py")
+
+
+@pytest.mark.skip(reason="No multi-height rows. No Rich objects.")
+def test_datatable_add_row_auto_height_sorted(snap_compare: Callable) -> None:
+    # Check that rows added with auto height computation look right.
+    assert snap_compare(
+        SNAPSHOT_APPS_DIR / "data_table_add_row_auto_height.py", press=["s"]
+    )
+
+
+def test_datatable_empty(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "empty.py")
+
+
+def test_datatable_empty_add_col(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "empty_add_col.py")
+
+
+def test_datatable_no_rows(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "no_rows.py")
+
+
+def test_datatable_no_rows_empty_sequence(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "no_rows_empty_sequence.py")
+
+
+def test_datatable_from_parquet(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "from_parquet.py")
+
+
+def test_datatable_from_records(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "from_records.py")
+
+
+def test_datatable_from_pydict(snap_compare: Callable) -> None:
+    assert snap_compare(SNAPSHOT_APPS_DIR / "from_pydict_with_col_labels.py")
--- a/tests/unit_tests/test_arrow_backend.py
+++ b/tests/unit_tests/test_arrow_backend.py
@ -0,0 +1,94 @@
+from __future__ import annotations
+
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+from typing import Sequence
+
+import pyarrow as pa
+from textual_fastdatatable import ArrowBackend
+
+
+def test_from_records(records: list[tuple[str | int, ...]]) -> None:
+    backend = ArrowBackend.from_records(records, has_header=True)
+    assert backend.column_count == 3
+    assert backend.row_count == 5
+    assert tuple(backend.columns) == records[0]
+
+
+def test_from_records_no_header(records: list[tuple[str | int, ...]]) -> None:
+    backend = ArrowBackend.from_records(records[1:], has_header=False)
+    assert backend.column_count == 3
+    assert backend.row_count == 5
+    assert tuple(backend.columns) == ("f0", "f1", "f2")
+
+
+def test_from_pydict(pydict: dict[str, Sequence[str | int]]) -> None:
+    backend = ArrowBackend.from_pydict(pydict)
+    assert backend.column_count == 3
+    assert backend.row_count == 5
+    assert backend.source_row_count == 5
+    assert tuple(backend.columns) == tuple(pydict.keys())
+
+
+def test_from_pydict_with_limit(pydict: dict[str, Sequence[str | int]]) -> None:
+    backend = ArrowBackend.from_pydict(pydict, max_rows=2)
+    assert backend.column_count == 3
+    assert backend.row_count == 2
+    assert backend.source_row_count == 5
+    assert tuple(backend.columns) == tuple(pydict.keys())
+
+
+def test_from_parquet(pydict: dict[str, Sequence[str | int]], tmp_path: Path) -> None:
+    tbl = pa.Table.from_pydict(pydict)
+    p = tmp_path / "test.parquet"
+    pa.parquet.write_table(tbl, str(p))
+
+    backend = ArrowBackend.from_parquet(p)
+    assert backend.data.equals(tbl)
+
+
+def test_empty_query() -> None:
+    data: dict[str, list] = {"a": []}
+    backend = ArrowBackend.from_pydict(data)
+    assert backend.column_content_widths == [0]
+
+
+def test_dupe_column_labels() -> None:
+    arr = pa.array([0, 1, 2, 3])
+    tab = pa.table([arr] * 3, names=["a", "a", "a"])
+    backend = ArrowBackend(data=tab)
+    assert backend.column_count == 3
+    assert backend.row_count == 4
+    assert backend.get_row_at(2) == [2, 2, 2]
+
+
+def test_timestamp_with_tz() -> None:
+    """
+    Ensure datetimes with offsets but no names do not crash the data table
+    when casting to string.
+    """
+    dt = datetime(2024, 1, 1, hour=15, tzinfo=timezone(offset=timedelta(hours=-5)))
+    arr = pa.array([dt, dt, dt])
+    tab = pa.table([arr], names=["created_at"])
+    backend = ArrowBackend(data=tab)
+    assert backend.column_content_widths == [29]
+
+
+def test_mixed_types() -> None:
+    data = [(1000,), ("hi",)]
+    backend = ArrowBackend.from_records(records=data)
+    assert backend
+    assert backend.row_count == 2
+    assert backend.get_row_at(0) == ["1000"]
+    assert backend.get_row_at(1) == ["hi"]
+
+
+def test_negative_timestamps() -> None:
+    dt = datetime(1, 1, 1, tzinfo=timezone.utc)
+    arr = pa.array([dt, dt, dt], type=pa.timestamp("s", tz="America/New_York"))
+    tab = pa.table([arr], names=["created_at"])
+    backend = ArrowBackend(data=tab)
+    assert backend.column_content_widths == [26]
+    assert backend.get_column_at(0) == [datetime.min, datetime.min, datetime.min]
+    assert backend.get_row_at(0) == [datetime.min]
+    assert backend.get_cell_at(0, 0) is datetime.min
--- a/tests/unit_tests/test_backends.py
+++ b/tests/unit_tests/test_backends.py
@ -0,0 +1,109 @@
+from __future__ import annotations
+
+import pytest
+from textual_fastdatatable.backend import DataTableBackend
+
+
+def test_column_content_widths(backend: DataTableBackend) -> None:
+    assert backend.column_content_widths == [1, 8, 6]
+
+
+def test_get_row_at(backend: DataTableBackend) -> None:
+    assert backend.get_row_at(0) == [1, "a", "foo"]
+    assert backend.get_row_at(4) == [5, "asdfasdf", "foofoo"]
+    with pytest.raises(IndexError):
+        backend.get_row_at(10)
+    with pytest.raises(IndexError):
+        backend.get_row_at(-1)
+
+
+def test_get_column_at(backend: DataTableBackend) -> None:
+    assert backend.get_column_at(0) == [1, 2, 3, 4, 5]
+    assert backend.get_column_at(2) == ["foo", "bar", "baz", "qux", "foofoo"]
+
+    with pytest.raises(IndexError):
+        backend.get_column_at(10)
+
+
+def test_get_cell_at(backend: DataTableBackend) -> None:
+    assert backend.get_cell_at(0, 0) == 1
+    assert backend.get_cell_at(4, 1) == "asdfasdf"
+    with pytest.raises(IndexError):
+        backend.get_cell_at(10, 0)
+    with pytest.raises(IndexError):
+        backend.get_cell_at(0, 10)
+
+
+def test_append_column(backend: DataTableBackend) -> None:
+    original_table = backend.data
+    backend.append_column("new")
+    assert backend.column_count == 4
+    assert backend.row_count == 5
+    assert backend.get_column_at(3) == [None] * backend.row_count
+
+    backend.append_column("def", default="zzz")
+    assert backend.column_count == 5
+    assert backend.row_count == 5
+    assert backend.get_column_at(4) == ["zzz"] * backend.row_count
+
+    assert backend.data.select(["first column", "two", "three"]).equals(original_table)
+
+
+def test_append_rows(backend: DataTableBackend) -> None:
+    original_table = backend.data
+    backend.append_rows([(6, "w", "x"), (7, "y", "z")])
+    assert backend.column_count == 3
+    assert backend.row_count == 7
+    assert backend.column_content_widths == [1, 8, 6]
+
+    backend.append_rows([(999, "w" * 12, "x" * 15)])
+    assert backend.column_count == 3
+    assert backend.row_count == 8
+    assert backend.column_content_widths == [3, 12, 15]
+
+    assert backend.data.slice(0, 5).equals(original_table)
+
+
+def test_drop_row(backend: DataTableBackend) -> None:
+    backend.drop_row(0)
+    assert backend.row_count == 4
+    assert backend.column_count == 3
+    assert backend.column_content_widths == [1, 8, 6]
+
+    backend.drop_row(3)
+    assert backend.row_count == 3
+    assert backend.column_count == 3
+    assert backend.column_content_widths == [1, 1, 3]
+
+    with pytest.raises(IndexError):
+        backend.drop_row(3)
+
+
+def test_update_cell(backend: DataTableBackend) -> None:
+    backend.update_cell(0, 0, 0)
+    assert backend.get_column_at(0) == [0, 2, 3, 4, 5]
+    assert backend.row_count == 5
+    assert backend.column_count == 3
+    assert backend.column_content_widths == [1, 8, 6]
+
+    backend.update_cell(3, 1, "z" * 50)
+    assert backend.get_row_at(3) == [4, "z" * 50, "qux"]
+    assert backend.row_count == 5
+    assert backend.column_count == 3
+    assert backend.column_content_widths == [1, 50, 6]
+
+
+def test_sort(backend: DataTableBackend) -> None:
+    original_table = backend.data
+    original_col_one = list(backend.get_column_at(0)).copy()
+    original_col_two = list(backend.get_column_at(1)).copy()
+    backend.sort(by="two")
+    assert backend.get_column_at(0) != original_col_one
+    assert backend.get_column_at(1) == sorted(original_col_two)
+
+    backend.sort(by=[("two", "descending")])
+    assert backend.get_column_at(0) != original_col_one
+    assert backend.get_column_at(1) == sorted(original_col_two, reverse=True)
+
+    backend.sort(by=[("first column", "ascending")])
+    assert backend.data.equals(original_table)
--- a/tests/unit_tests/test_create_backend.py
+++ b/tests/unit_tests/test_create_backend.py
@ -0,0 +1,54 @@
+from datetime import date, datetime
+
+import pyarrow as pa
+from textual_fastdatatable.backend import create_backend
+
+MAX_32BIT_INT = 2**31 - 1
+MAX_64BIT_INT = 2**63 - 1
+
+
+def test_empty_sequence() -> None:
+    backend = create_backend(data=[])
+    assert backend
+    assert backend.row_count == 0
+    assert backend.column_count == 0
+    assert backend.columns == []
+    assert backend.column_content_widths == []
+
+
+def test_infinity_timestamps() -> None:
+    from_py = create_backend(
+        data={"dt": [date.max, date.min], "ts": [datetime.max, datetime.min]}
+    )
+    assert from_py
+    assert from_py.row_count == 2
+
+    from_arrow = create_backend(
+        data=pa.table(
+            {
+                "dt32": [
+                    pa.scalar(MAX_32BIT_INT, type=pa.date32()),
+                    pa.scalar(-MAX_32BIT_INT, type=pa.date32()),
+                ],
+                "dt64": [
+                    pa.scalar(MAX_64BIT_INT, type=pa.date64()),
+                    pa.scalar(-MAX_64BIT_INT, type=pa.date64()),
+                ],
+                "ts": [
+                    pa.scalar(MAX_64BIT_INT, type=pa.timestamp("s")),
+                    pa.scalar(-MAX_64BIT_INT, type=pa.timestamp("s")),
+                ],
+                "tns": [
+                    pa.scalar(MAX_64BIT_INT, type=pa.timestamp("ns")),
+                    pa.scalar(-MAX_64BIT_INT, type=pa.timestamp("ns")),
+                ],
+            }
+        )
+    )
+    assert from_arrow
+    assert from_arrow.row_count == 2
+    assert from_arrow.get_row_at(0) == [date.max, date.max, datetime.max, datetime.max]
+    assert from_arrow.get_row_at(1) == [date.min, date.min, datetime.min, datetime.min]
+    assert from_arrow.get_column_at(0) == [date.max, date.min]
+    assert from_arrow.get_column_at(2) == [datetime.max, datetime.min]
+    assert from_arrow.get_cell_at(0, 0) == date.max