render_data_uri fails with TypeError: a bytes-like object is required, not 'str'

[rouilj]

Running:

        elif self.output_type == 'data:':
            image = chart.render_data_uri(is_unicode=True)

results in a traceback (with or without is_unicode being passed). Here is the traceback:

[/usr/lib/python3.6/base64.py](file://usr/lib/python3.6/base64.py) in b64encode(s='<svg xmlns:xlink="http://www.w3.org/1999/xlink" ...gends" transform="translate(390, 82)"/></g></svg>', altchars=None)
   56     application to e.g. generate url or filesystem safe Base64 strings.
   57     """
   58     encoded = binascii.b2a_base64(s, newline=False)
      encoded = undefined, global binascii = <module 'binascii' (built-in)>, global b2a_base64 = undefined, s = '<svg xmlns:xlink="http://www.w3.org/1999/xlink" ...gends" transform="translate(390, 82)"/></g></svg>', global newline = undefined
   59     if altchars is not None:
   60         assert len(altchars) == 2, repr(altchars)

[/usr/local/lib/python3.6/dist-packages/pygal/graph/public.py](file://usr/local/lib/python3.6/dist-packages/pygal/graph/public.py) in render_data_uri(self=<pygal.graph.pie.Pie object>, **kwargs={'force_uri_protocol': 'https', 'is_unicode': True})
  105         return "data:image/svg+xml;charset=utf-8;base64,%s" % (
  106             base64.b64encode(
  107                 self.render(**kwargs)
      self = <pygal.graph.pie.Pie object>, global render = undefined, kwargs = {'force_uri_protocol': 'https', 'is_unicode': True}
  108             ).decode('utf-8').replace('\n', '')
  109         )

looks like self.render() is returning a string when it needs to be bytes??

[GarrettPetersen]

Just wanted to chime in to say I have the same issue. It's easy enough to make a workaround, but we should fix this in pygal.