Don't support passing None instead of "none" as errorbar format.

anntzer · anntzer · commit b3aa6674a3d4 · 2017-12-25T20:39:00.000-08:00
diff --git a/doc/api/api_changes/2017-09-22-AL-removal-of-deprecated-features.rst b/doc/api/api_changes/2017-09-22-AL-removal-of-deprecated-features.rst
@@ -17,3 +17,6 @@ The ``spectral`` colormap has been removed.  The ``Vega*`` colormaps, which
 were aliases for the ``tab*`` colormaps, have been removed.
 
 ``mencoder`` can no longer be used to encode animations.
+
+Passing ``None`` instead of ``"none"`` as format to `~.Axes.errorbar` is no
+longer supported.
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -2857,13 +2857,6 @@ def errorbar(self, x, y, yerr=None, xerr=None,
         holdstate = self._hold
         self._hold = True
 
-        if fmt is None:
-            fmt = 'none'
-            msg = ('Use of None object as fmt keyword argument to ' +
-                   'suppress plotting of data values is deprecated ' +
-                   'since 1.4; use the string "none" instead.')
-            warnings.warn(msg, mplDeprecation, stacklevel=1)
-
         plot_line = (fmt.lower() != 'none')
         label = kwargs.pop("label", None)
 
