Deprecate the TTFPATH & AFMPATH environment variables.

anntzer · anntzer · commit a5fa73ae3163 · 2019-12-27T19:37:25.000+01:00
These undocumented environment variables allow one to selectively add
paths to the font cache... but only if the font cache doesn't exist yet
(they don't force cache regen).  The font-cache regen API (_rebuild())
is also private (even though one can trigger it "publically" e.g. by
calling `findfont` with a nonexisting font...).

Instead, we now expose `addfont()` which is a documented API for
registering fonts with the font manager.
diff --git a/doc/api/next_api_changes/deprecations.rst b/doc/api/next_api_changes/deprecations.rst
@@ -73,3 +73,9 @@ Revert deprecation \*min, \*max keyword arguments to ``set_x/y/zlim_3d()``
 These keyword arguments  were deprecated in 3.0, alongside with the respective
 parameters in ``set_xlim()`` / ``set_ylim()``. The deprecations of the 2D
 versions were already reverted in in 3.1.
+
+The ``TTFPATH`` and ``AFMPATH`` environment variables
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Support for the (undocumented) ``TTFPATH`` and ``AFMPATH`` environment
+variables is deprecated.  Additional fonts may be registered using
+``matplotlib.font_manager.fontManager.addfont()``.
diff --git a/lib/matplotlib/font_manager.py b/lib/matplotlib/font_manager.py
@@ -974,6 +974,9 @@ def __init__(self, size=None, weight='normal'):
                     paths.extend(ttfpath.split(':'))
                 else:
                     paths.append(ttfpath)
+                cbook.warn_deprecated(
+                    "3.3", name=pathname, obj_type="environment variable",
+                    alternative="FontManager.addfont()")
         _log.debug('font search path %s', str(paths))
         #  Load TrueType fonts and create font dictionary.
 
