At least close ']' for lists of lists. Sorry, lists of lists of lists.

Also, you have to ensure that the sublist is longer than "[...]".
Where "..." == end.

Otherwise, you might end up with: ", ...]". Where we're closing
something that we no longer open!

Author: theengineear

Diff for: plotly/graph_objs/graph_objs_tools.py

@@ -36,6 +36,8 @@ def curtail_val_repr(val, max_chars, add_delim=False):
         if isinstance(val, six.string_types):
             # TODO: can we assume this ends in "'"
             r = r[:max_chars - len(end + "'")] + end + "'"
+        elif isinstance(val, list) and max_chars >= len("[{end}]".format(end)):
+            r = r[:max_chars - len(end + ']')] + end + ']'
         else:
             r = r[:max_chars - len(end)] + end
     if add_delim: