Add multiple label support for Axes.plot()

yozhikoff · yozhikoff · commit b99c8ac3dfa9 · 2020-12-23T22:56:26.000+03:00
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -448,8 +448,9 @@ def _plot_args(self, tup, kwargs, return_kwargs=False):
         if ncx > 1 and ncy > 1 and ncx != ncy:
             raise ValueError(f"x has {ncx} columns but y has {ncy} columns")
 
-        if ('label' in kwargs and isinstance(kwargs['label'], Iterable)
-                        and not isinstance(kwargs['label'], str)):
+        if ('label' in kwargs and max(ncx, ncy) > 1
+                    and isinstance(kwargs['label'], Iterable)
+                    and not isinstance(kwargs['label'], str)):
             if len(kwargs['label']) != max(ncx, ncy):
                 raise ValueError(f"if label is iterable label and input data"
                                  f" must have same length, but have lengths "
