MNT: add error check if not a number

jklymak · jklymak · commit ef7afc4277da · 2019-02-10T14:07:06.000-08:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -3914,7 +3914,10 @@ def dopatch(xs, ys, **kwargs):
             positions = list(range(1, N + 1))
         elif len(positions) != N:
             raise ValueError(datashape_message.format("positions"))
+
         positions = np.array(positions)
+        if len(positions) > 0 and not isinstance(positions[0], Number):
+            raise TypeError("positions should be an iterable of numbers")
 
         # width
         if widths is None:
