matplotlib · QuLogic · Jan 22, 2021 · Dec 19, 2020
diff --git a/doc/api/next_api_changes/deprecations/19153-LPS.rst b/doc/api/next_api_changes/deprecations/19153-LPS.rst
@@ -0,0 +1,5 @@
+``pyplot.gca()``, ``Figure.gca``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Passing keyword arguments to `.pyplot.gca` or `.figure.Figure.gca` will not be
+supported in a future release.
diff --git a/doc/users/next_whats_new/axes_kwargs_collision.rst b/doc/users/next_whats_new/axes_kwargs_collision.rst
@@ -0,0 +1,21 @@
+Changes to behavior of Axes creation methods (``gca()``, ``add_axes()``, ``add_subplot()``)
+-------------------------------------------------------------------------------------------
+
+The behavior of the functions to create new axes (`.pyplot.axes`,
+`.pyplot.subplot`, `.figure.Figure.add_axes`,
+`.figure.Figure.add_subplot`) has changed. In the past, these functions would
+detect if you were attempting to create Axes with the same keyword arguments as
+already-existing axes in the current figure, and if so, they would return the
+existing Axes. Now, these functions will always create new Axes. A special
+exception is `.pyplot.subplot`, which will reuse any existing subplot with a
+matching subplot spec. However, if there is a subplot with a matching subplot
+spec, then that subplot will be returned, even if the keyword arguments with
+which it was created differ.
+
+Correspondingly, the behavior of the functions to get the current Axes
+(`.pyplot.gca`, `.figure.Figure.gca`) has changed. In the past, these functions
+accepted keyword arguments. If the keyword arguments matched an
+already-existing Axes, then that Axes would be returned, otherwise new Axes
+would be created with those keyword arguments. Now, the keyword arguments are
+only considered if there are no axes at all in the current figure. In a future
+release, these functions will not accept keyword arguments at all.
diff --git a/lib/matplotlib/axes/_subplots.py b/lib/matplotlib/axes/_subplots.py
@@ -1,5 +1,4 @@
 import functools
-import uuid
 
 from matplotlib import _api, docstring
 import matplotlib.artist as martist
@@ -142,16 +141,7 @@ def _make_twin_axes(self, *args, **kwargs):
             # which currently uses this internal API.
             if kwargs["sharex"] is not self and kwargs["sharey"] is not self:
                 raise ValueError("Twinned Axes may share only one axis")
-        # The dance here with label is to force add_subplot() to create a new
-        # Axes (by passing in a label never seen before).  Note that this does
-        # not affect plot reactivation by subplot() as twin axes can never be
-        # reactivated by subplot().
-        sentinel = str(uuid.uuid4())
-        real_label = kwargs.pop("label", sentinel)
-        twin = self.figure.add_subplot(
-            self.get_subplotspec(), *args, label=sentinel, **kwargs)
-        if real_label is not sentinel:
-            twin.set_label(real_label)
+        twin = self.figure.add_subplot(self.get_subplotspec(), *args, **kwargs)
         self.set_adjustable('datalim')
         twin.set_adjustable('datalim')
         self._twinned_axes.join(self, twin)

diff --git a/lib/matplotlib/cbook/__init__.py b/lib/matplotlib/cbook/__init__.py
@@ -606,6 +606,9 @@ def __len__(self):
     def __getitem__(self, ind):
         return self._elements[ind]
 
+    def as_list(self):
+        return list(self._elements)
+
     def forward(self):
         """Move the position forward and return the current element."""
         self._pos = min(self._pos + 1, len(self._elements) - 1)