matplotlib/matplotlib: REL: v3.7.0

Highlights of this release include:

• Plotting and Annotation improvements
  • hatch parameter for pie
  • Polar plot errors drawn in polar coordinates
  • Additional format string options in ~matplotlib.axes.Axes.bar_label
  • ellipse boxstyle option for annotations
  • The extent of imshow can now be expressed with units
  • Reversed order of legend entries
  • pcolormesh accepts RGB(A) colors
  • View current appearance settings for ticks, tick labels, and gridlines
  • Style files can be imported from third-party packages
• Improvements to 3D Plotting
  • 3D plot pan and zoom buttons
  • adjustable keyword argument for setting equal aspect ratios in 3D
  • Poly3DCollection supports shading
  • rcParam for 3D pane color
• Figure and Axes Layout
  • colorbar now has a location keyword argument
  • Figure legends can be placed outside figures using constrained_layout
  • Per-subplot keyword arguments in subplot_mosaic
  • subplot_mosaic no longer provisional
• Widget Improvements
  • Custom styling of button widgets
  • Blitting in Button widgets
• Other Improvements
  • Source links can be shown or hidden for each Sphinx plot directive
  • Figure hooks
• New & Improved Narrative Documentation
  • Brand new :doc:Animations </tutorials/introductory/animation_tutorial> tutorial.
  • New grouped and stacked bar chart <../../gallery/index.html#lines_bars_and_markers>_ examples.
  • New section for new contributors and reorganized git instructions in the :ref:contributing guide<contributing>.
  • Restructured :doc:/tutorials/text/annotations tutorial.