⚡️ Speed up function fignum_exists by 7%

lib/matplotlib/_pylab_helpers.py

@@ -68,8 +68,14 @@ def destroy(cls, num):
     @classmethod
     def destroy_fig(cls, fig):
         """Destroy figure *fig*."""
-        num = next((manager.num for manager in cls.figs.values()
-                    if manager.canvas.figure == fig), None)
+        num = next(
+            (
+                manager.num
+                for manager in cls.figs.values()
+                if manager.canvas.figure == fig
+            ),
+            None,
+        )
         if num is not None:
             cls.destroy(num)
 
@@ -106,7 +112,8 @@ def _set_new_active_manager(cls, manager):
         """Adopt *manager* into pyplot and make it the active manager."""
         if not hasattr(manager, "_cidgcf"):
             manager._cidgcf = manager.canvas.mpl_connect(
-                "button_press_event", lambda event: cls.set_active(manager))
+                "button_press_event", lambda event: cls.set_active(manager)
+            )
         fig = manager.canvas.figure
         fig.number = manager.num
         label = fig.get_label()

lib/matplotlib/pyplot.py

@@ -78,6 +78,7 @@
 from matplotlib.colors import _color_sequences, Colormap
 
 import numpy as np
+import matplotlib.backends
 
 if TYPE_CHECKING:
     from collections.abc import Callable, Hashable, Iterable, Sequence
@@ -1088,7 +1089,7 @@ def fignum_exists(num: int | str) -> bool:
     return (
         _pylab_helpers.Gcf.has_fignum(num)
         if isinstance(num, int)
-        else num in get_figlabels()
+        else num in _figlabels_set()
     )
 
 
@@ -4492,3 +4493,10 @@ def nipy_spectral() -> None:
     image if there is one. See ``help(colormaps)`` for more information.
     """
     set_cmap("nipy_spectral")
+
+
+def _figlabels_set() -> set[Any]:
+    """Helper for fast membership check of string figure labels."""
+    return {
+        m.canvas.figure.get_label() for m in _pylab_helpers.Gcf.get_all_fig_managers()
+    }