Allow handles to be passed as a nparray and not just a Python list

AllisonBrand · web-flow · commit e1c601d8b939 · 2026-04-07T16:20:25.000-07:00
This is a one line edit. 
I replaced "if handles and labels:" with "if handles is not None and labels is not None:"

I ran into an error when I passed the handles as a nparray instead of a Python list: "ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()".

I felt it should work for any iterable that contains the handles, and this tiny edit solved the issue with nparrays.
diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -1363,7 +1363,7 @@ def _parse_legend_args(axs, *args, handles=None, labels=None, **kwargs):
                            f"len(handles) = {len(handles)} "
                            f"len(labels) = {len(labels)}")
     # if got both handles and labels as kwargs, make same length
-    if handles and labels:
+    if handles is not None and labels is not None:
         handles, labels = zip(*zip(handles, labels))
 
     elif handles is not None and labels is None:
