Flask raises UnicodeEncodeError (latin-1) when send attachment with UTF-8 characters
The problem is that when using as_attachement=True the filename is sent in the headers. Unfortunately it seems that flask does not yet support rfc5987 which specifies how to encode attachment file names in a different encoding other than latin1.
The easiest solution in this case would be to drop as_attachement=True, then it won't be sent with a Content-Disposition header, which avoids this problem.
If you really have to send the Content-Disposition header you could try the code posted in the related issue:
response = make_response(send_file(out_file)) basename = os.path.basename(out_file) response.headers["Content-Disposition"] = \ "attachment;" \ "filename*=UTF-8''{utf_filename}".format( utf_filename=quote(basename.encode('utf-8')) ) return responseThis should be fixed in the next release (>0.12)