Merge pull request #9596 from matplotlib/auto-backport-of-pr-9589

QuLogic · web-flow · commit e9fcb97b46ff · 2017-10-27T18:10:13.000-04:00
Backport PR #9589 on branch v2.1.x
diff --git a/lib/matplotlib/mlab.py b/lib/matplotlib/mlab.py
@@ -2330,7 +2330,7 @@ def rec_append_fields(rec, names, arrs, dtypes=None):
     values themselves.
     """
     if (not isinstance(names, six.string_types) and cbook.iterable(names)
-            and len(names) and isinstance(names[0]), six.string_types):
+            and len(names) and isinstance(names[0], six.string_types)):
         if len(names) != len(arrs):
             raise ValueError("number of arrays do not match number of names")
     else:  # we have only 1 name and 1 array
