Backport PR #12572: Fix singleton hist labels (#12594)

meeseeksmachine · timhoffm · commit 83f03e6dde59 · 2018-10-24T19:54:28.000+02:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -6759,6 +6759,8 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
             labels = [None]
         elif isinstance(label, str):
             labels = [label]
+        elif not np.iterable(label):
+            labels = [str(label)]
         else:
             labels = [str(lab) for lab in label]
 
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -3065,6 +3065,21 @@ def test_hist_emptydata():
     ax.hist([[], range(10), range(10)], histtype="step")
 
 
+def test_hist_labels():
+    # test singleton labels OK
+    fig, ax = plt.subplots()
+    l = ax.hist([0, 1], label=0)
+    assert l[2][0].get_label() == '0'
+    l = ax.hist([0, 1], label=[0])
+    assert l[2][0].get_label() == '0'
+    l = ax.hist([0, 1], label=None)
+    assert l[2][0].get_label() == '_nolegend_'
+    l = ax.hist([0, 1], label='0')
+    assert l[2][0].get_label() == '0'
+    l = ax.hist([0, 1], label='00')
+    assert l[2][0].get_label() == '00'
+
+
 @image_comparison(baseline_images=['transparent_markers'], remove_text=True)
 def test_transparent_markers():
     np.random.seed(0)
