Plotly

Fixed

- Fix `AttributeError: module 'plotly.graph_objs' has no attribute 'FigureWidget'` exception on `from plotly.graph_objs import *` when `ipywidgets` is not installed. Error also occurred when importing `plotly.figure_factor`. It is now possible to import `plotly.graph_objs.FigureWidget` when `ipywidgets` is not installed, and an informative `ImportError` exception will be raised in the `FigureWidget` constructor ([2443](https://github.com/plotly/plotly.py/issues/2443), [#1111](https://github.com/plotly/plotly.py/issues/1111)).
- Fix `TypeError: unhashable type: 'Template'` during `Figure` construction when `plotly.io.templates.default` is set to a `Template` object rather than a string.

Updated

- Updated Plotly.js to version 1.54.1. See the [plotly.js CHANGELOG](https://github.com/plotly/plotly.js/blob/v1.54.1/CHANGELOG.md) for more information. The main new feature of this version of Plotly.js is the possibility to draw layout shapes, using custom dragmodes and corresponding modebar buttons.
- The sphinx-gallery scraper has been updated to work with different structures of galleries [2149](https://github.com/plotly/plotly.py/pull/2419)

Added

- The `hover_data` parameter of `px` functions can now be a dictionary. This makes it possible to skip hover information for some arguments or to change the formatting of hover information [2377](https://github.com/plotly/plotly.py/pull/2377).
- It's now possible to build a development version of Plotly.py against the build artifacts from a non-`master` branch of Plotly.js, which makes for faster QA and development cycles [2349](https://github.com/plotly/plotly.py/pull/2349). Thanks [zouhairm](https://github.com/zouhairm) for this Pull Request!

Fixed

- Plotly Express trendlines now handle missing data correctly [2357](https://github.com/plotly/plotly.py/pull/2357)

Performance

This version includes several performance improvements ([2368](https://github.com/plotly/plotly.py/pull/2368), [#2403](https://github.com/plotly/plotly.py/pull/2403)).

- Child graph objects (e.g. `figure.layout.xaxis`) are no longer created eagerly during graph object construction. Instead, they are created lazily the first time the property is accessed.
- Property validation is now disabled for select internal operations.
- When used with Python 3.7 and above, plotly.py now takes advantage of [PEP-562](https://www.python.org/dev/peps/pep-0562/) to perform submodule imports lazily. This dramatically improves import times.

Updated

- Updated Plotly.js to version 1.53.0. See the [plotly.js CHANGELOG](https://github.com/plotly/plotly.js/blob/v1.53.0/CHANGELOG.md) for more information on the numerous new features and bug fixes of this release. The main features of the Plotly.js release are
- Introduce range breaks on date axes (for example, to remove week-ends) via `layout.xaxis.rangebreaks`
- Introduce a new unified x (or y) hovermode (`layout.hovermode="x unified"`), in which the hover box shows the information for all traces at a given x (or y) position
- Add `node.customdata` and `link.customdata` to sankey traces
- Updated [contributing notes](https://github.com/plotly/plotly.py/blob/master/contributing.md) for more explanations on how to contribute to plotly.py [#2290](https://github.com/plotly/plotly.py/pull/2290). Please give feedback on these notes!
- Updated documentation examples [2325](https://github.com/plotly/plotly.py/pull/2325), and to show how to color links in Sankey diagrams [#2291](https://github.com/plotly/plotly.py/pull/2291).
- Special thanks to [SylwiaOliwia2](https://github.com/SylwiaOliwia2) and [dangercrow](https://github.com/dangercrow) for improving our documentation!


Added

- `px.imshow` now accepts [`xarray`](http://xarray.pydata.org/) inputs, with metadata being used for axis labels, hover and colorbar [#2166](https://github.com/plotly/plotly.py/pull/2166)


Fixed

- Fixed handling of `opacity` in `px.pie`, `px.funnel_area`, `px.density_mapbox`, `px.funnel` [2317](https://github.com/plotly/plotly.py/pull/2317), with thanks to [tvaucher](https://github.com/tvaucher) for the contribution!

Updated

- The documentation of the API https://plot.ly/python-api-reference/ now
documents the full API [2243](https://github.com/plotly/plotly.py/pull/2243)
- New documentation examples for facets [2235](https://github.com/plotly/plotly.py/pull/2235), legend [#2227](https://github.com/plotly/plotly.py/pull/2227), subplots [#2226](https://github.com/plotly/plotly.py/pull/2226), axes [#2234](https://github.com/plotly/plotly.py/pull/2234) and histograms [#2242](https://github.com/plotly/plotly.py/pull/2242).
Thanks to [SylwiaOliwia2](https://github.com/SylwiaOliwia2) for all these great
examples!

Fixed

- Jupyterlab extension now compatible with both Jupyterlab 1.2 and 2.0 [2261](https://github.com/plotly/plotly.py/pull/2261) with thanks to [consideRatio](https://github.com/consideRatio) for the contribution!
- Fixed a bug when using boolean values for the color argument of px functions [2127](https://github.com/plotly/plotly.py/pull/2127)
- Corrected import bug which was occurring with old versions of ipywidgets [2265](https://github.com/plotly/plotly.py/pull/2265)
- Fixed python 3.8 syntax warning [2262](https://github.com/plotly/plotly.py/pull/2262), with thanks to [sgn](https://github.com/sgn) for the contribution!

Updated

- Removed development dependency on `nose` testing framework [2217](https://github.com/plotly/plotly.py/pull/2217)

Fixed

- JupyterLab extension now compatible with JupyterLab 2.0 [2245](https://github.com/plotly/plotly.py/pull/2245) with thanks to [consideRatio](https://github.com/consideRatio) for the contribution!

Fixed

- Fix build errors in JupyterLab extension by pinning version of `types/plotly.js` [2223](https://github.com/plotly/plotly.py/issues/2223)