Merge pull request #17717 from meeseeksmachine/auto-backport-of-pr-17705-on-v3.3.x

tacaswell · web-flow · commit aa13340cb81c · 2020-06-22T13:26:40.000-04:00
Backport PR #17705 on branch v3.3.x (Keep cachedRenderer as None when pickling Figure.)
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -2108,8 +2108,10 @@ def __getstate__(self):
         # The canvas cannot currently be pickled, but this has the benefit
         # of meaning that a figure can be detached from one canvas, and
         # re-attached to another.
-        for attr_to_pop in ('canvas', '_cachedRenderer'):
-            state.pop(attr_to_pop, None)
+        state.pop("canvas")
+
+        # Set cached renderer to None -- it can't be pickled.
+        state["_cachedRenderer"] = None
 
         # add version information to the state
         state['__mpl_version__'] = _mpl_version
