matplotlib · oscargus · May 19, 2025 · May 19, 2025
diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -459,6 +459,7 @@ def __init__(
            labels = [*reversed(labels)]
            handles = [*reversed(handles)]

+        handles = list(handles)
        if len(handles) < 2:
            ncols = 1
        self._ncols = ncols if ncols != 1 else ncol

diff --git a/lib/matplotlib/tests/test_legend.py b/lib/matplotlib/tests/test_legend.py
@@ -42,6 +42,18 @@ def test_legend_ordereddict():
              loc='center left', bbox_to_anchor=(1, .5))


+def test_legend_generator():
+    # smoketest that generator inputs work
+    fig, ax = plt.subplots()
+    ax.plot([0, 1])
+    ax.plot([0, 2])
+
+    handles = (line for line in ax.get_lines())
+    labels = (label for label in ['spam', 'eggs'])
+
+    ax.legend(handles, labels, loc='upper left')
+
+
 @image_comparison(['legend_auto1.png'], remove_text=True)
 def test_legend_auto1():
    """Test automatic legend placement"""