v0.19.0

Changelog

All notable changes to this project will be documented in this file.

Unreleased

0.19.0 - 2026-08-20

• A multi-line cell now ends in a dim …⏎, so a value with lines below the first no
  longer reads as the one line it shows
  (tconbeer/harlequin#635,
  tconbeer/harlequin#771).
• Multi-line cells now get a tooltip.
• Multi-line values are now measured for column width as they are rendered.

0.18.0 - 2026-08-19

• Fixes the flickering tooltip reported in
  tconbeer/harlequin#894. Tooltip
  content is now truncated (with a … (truncated) marker) to at most half the height of
  the screen, so the tooltip can no longer be clamped over the mouse, which caused
  Textual to clear and re-show it indefinitely.
• The backend now measures column widths based on whether or not strings will be
  rendered as Rich markup (#171).
• String columns are now measured in terminal cells instead of counted in characters (#144).
• Column labels are now measured the same way cell values are (#144).

0.17.1 - 2026-08-10

• textual_fastdatatable.backend can now be imported without importing rich, which is
  now imported (with the Console it provides) on the first column-width measurement, so
  consumers that never render skip ~50 modules and ~30ms
  (#168).

0.17.0 - 2026-08-09

• create_backend() (and the backend constructors it dispatches to) now accept a
  column_names argument: the labels the caller has for the data's columns, which are
  applied in place of the ones the data carries or lacks. create_backend(None, column_names=[...]) now builds an empty table with those columns instead of raising,
  and records use those names in place of f0, f1, ...
  (#165).

0.16.1 - 2026-08-07

• textual_fastdatatable.backend can now be imported without importing Textual: the
  DataTable widget is now imported lazily by the package root (PEP 562), so
  from textual_fastdatatable.backend import create_backend no longer drags in the widget
  framework. from textual_fastdatatable import DataTable is unchanged, and still imports
  Textual at the moment the name is accessed.
• pyarrow.parquet is now imported lazily, inside ArrowBackend.from_parquet(), instead
  of at module scope in backend.py.
• Together these cut from textual_fastdatatable.backend import create_backend from 359
  to 186 imported modules on Python 3.10 (measured against this project's required
  dependencies, without the polars extra). There are no API changes.

0.16.0 - 2026-08-05

Features

• DataTable(data=...) and create_backend() now accept a pandas DataFrame, which is
  converted with the ArrowBackend.
• Copying a selection is now bound to super+c (cmd+c) as well as ctrl+c, matching the
  copy bindings Textual added in 7.3.0 for terminals that report the command key.

Dependency Changes (Breaking!)

• Drops support for Python 3.9; the minimum supported version is now Python 3.10.
• Requires Textual >= 7.3.0.
• Drops the numpy and pandas dependencies.
• pyarrow upper bounds have been removed.
• Adds a test that resolves this project's dependencies for every supported Python (3.10 -
  3.14) and platform (Linux, macOS, and Windows, on x86_64 and arm64) with wheels only.
• Declares typing-extensions as a dependency; it was imported but only installed as a
  transitive dependency of Textual.

0.15.0 - 2026-08-03

• Fixes the crash reported in tconbeer/harlequin#933 by forward render_markup in tooltip path (thank you @crossi-dev!).
• Fixes the crash reported in tconbeer/harlequin#974 by escaping and truncating bytes values in cell formatter (thank you @Pawansingh3889!).

0.14.0 - 2025-10-25

• Fixes column rendering bug to make compatible with recent versions of Textual.
• Updates pyarrow and numpy dependencies to provide compatibility with Python 3.14

0.13.0 - 2025-10-16

• Makes dependecies more exact to ensure installations use wheels for large dependencies (numpy, pyarrow, pandas, etc.).

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)

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).
• 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).

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).

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 tab and shift+tab to cycle to the next/prev row if at the end/start of a row or table.
• Fixes a crash from pressing ctrl+c when the cursor type is column.

0.6.0 - 2024-01-05

Features

• Adds keybindings for navigating the cursor in the data table. ctrl+right/left/up/down/home/end (with shift variants), tab, shift+tab, ctrl+a 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 <3.9 for timezone support.
• Fixes a bug where Arrow crashes while casting timestamptz to string (tconbeer/harlequin#382).

Performance

• Vectorizes fallback string casting for datatypes unsupported by pc.cast (#8)

0.5.0 - 2023-12-21

Features

• Adds a range cursor type that will highlight a range of selected cells, like Excel.
• ctrl+c 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).

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).

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).

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).

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).

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.