def on_cmd_test(bot, update):
    f=open('/tmp/test.txt','rb')
    bot.send_document(update.message.chat_id,document=f,caption=u'Привет')
    f.close
    return

2018-07-12 19:28:50,139 telegram.ext.dispatcher ERROR An uncaught error was raised while processing the update
Traceback (most recent call last):
  File "/opt/draw-gpx-bot/lib/telegram/ext/dispatcher.py", line 279, in process_update
    handler.handle_update(update, self)
  File "/opt/draw-gpx-bot/lib/telegram/ext/commandhandler.py", line 173, in handle_update
    return self.callback(dispatcher.bot, update, **optional_args)
  File "./drawgpxbot.py", line 193, in on_cmd_test
    bot.send_document(update.message.chat_id,document=f,caption=u'Привет')
  File "/opt/draw-gpx-bot/lib/telegram/bot.py", line 60, in decorator
    result = func(self, *args, **kwargs)
  File "/opt/draw-gpx-bot/lib/telegram/bot.py", line 85, in decorator
    result = self._request.post(url, data, timeout=kwargs.get('timeout'))
  File "/opt/draw-gpx-bot/lib/telegram/utils/request.py", line 270, in post
    'POST', url, body=data.to_form(), headers=data.headers, **urlopen_kwargs)
  File "/opt/draw-gpx-bot/lib/telegram/files/inputfile.py", line 120, in to_form
    form_boundary, 'Content-Disposition: form-data; name="%s"' % name, '', str(value)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-5: ordinal not in range(128)