MNT: Don't rely on RcParams being a dict subclass in internal code

timhoffm · timhoffm · commit 7f5afe3afd2f · 2024-08-15T16:52:54.000+02:00
Eventually, we want to be able to remove the dict subclassing from RcParams, which will allow better initialization and handling. We've publically announced that people should not rely on dict in https://matplotlib.org/stable/api/prev_api_changes/api_changes_3.7.0.html#rcparams-type This is an internal cleanup step to remove the dict-assumption and a preparation for further refactoring.
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
@@ -410,7 +410,7 @@ def switch_backend(newbackend: str) -> None:
             switch_backend("agg")
             rcParamsOrig["backend"] = "agg"
             return
-    old_backend = rcParams._get('backend')  # prevents triggering backend resolution
+    old_backend = rcParams._get('backend')  # get without triggering backend resolution
 
     module = backend_registry.load_backend_module(newbackend)
     canvas_class = module.FigureCanvas
