Altair

Enhancements

- Several documentation cleanups & new examples

Bug Fixes

- Fix incompatibility with pandas version 0.24 (1315)

Includes many reworked examples in the example gallery.

Enhancements

- Better errors for non-string column names, as well as automatic conversion of `pandas.RangeIndex` columns to strings (1107)
- Renderers now have `set_embed_options()` method (1203)
- Added kaggle renderer & more HTML output options (1123)


Maintenance

- fix typing requirement in Python 3.6+ (1185)
- Added support & CI testing for Python 3.7 (1008)

Bug fixes

- Selection predicates now recognize all valid entries (1143)
- Python 2 support for `chart.save()` (1134)

Bug Fixes

- fix missing JSON resource in `altair.vega.v4` (1097)

Bug Fixes

- appropriate handling of InlineData in dataset consolidation (1092)

- fix admonition formatting in documentation page (1094)

Enhancements

- better handling of datetimes and timezones (1053)

- all inline datasets are now converted to named datasets and stored at the
top level of the chart. This behavior can be disabled by setting
``alt.data_transformers.consolidate_datasets = False`` (951 & 1046)

- more streamlined shorthand syntax for window transforms (957)

Maintenance

- update from Vega-Lite 2.4.3 to Vega-Lite 2.6.0; see vega-lite change-logs [2.5.0](https://github.com/vega/vega-lite/releases/tag/v2.5.0) [2.5.1](https://github.com/vega/vega-lite/releases/tag/v2.5.1) [2.5.2](https://github.com/vega/vega-lite/releases/tag/v2.5.2) [2.6.0](https://github.com/vega/vega-lite/releases/tag/v2.6.0)

Backward-incompatible changes

- ``alt.SortField`` renamed to ``alt.EncodingSortField`` and
``alt.WindowSortField`` renamed to ``alt.SortField`` (923)

Bug Fixes

- Fixed serialization of logical operands on selections within
``transform_filter()``: (1075)

- Fixed sphinx issue which embedded chart specs twice (1088)

- Avoid Selenium import until it is actually needed (982)

Enhancements

- add a ``scale_factor`` argument to ``chart.save()`` to allow the
size/resolution of saved figures to be adjusted. (918)

- add an ``add_selection()`` method to add selections to charts (832)

- add ``chart.serve()`` and ``chart.display()`` methods for more flexiblity
in displaying charts (831)

- allow multiple fields to be passed to encodings such as ``tooltip``
and ``detail`` (830)

- make ``timeUnit`` specifications more succinct, by parsing them in a manner
similar to aggregates (866)

- make ``to_json()`` and ``to_csv()`` have deterministic filenames, so in json
mode a single datasets will lead to a single on-disk serialization (862)

Breaking Changes

- make ``data`` the first argument for all compound chart types to match the
semantics of ``alt.Chart`` (this includes ``alt.FacetChart``,
``alt.LayerChart``, ``alt.RepeatChart``, ``alt.VConcatChart``, and
``alt.HConcatChart``) (895).

- update vega-lite to version 2.4.3 (836)

- Only API change is internal: ``alt.MarkProperties`` is now ``alt.MarkConfig``

Maintenance

- update vega to v3.3 & vega-embed to v3.11 in html output & colab renderer (838)