Hi there.
It is a good idea to share a clone link to your application if possible (a small example to demonstrate the issue). This makes it much easier to debug. Click the 
icon and follow the sharing instructions. Also you can format your code in the forum by wrapping your code in triple backticks, for example:
```python
print(‘nicely formatted code’)
```
One thought is that you may need the u prefix for any non-ASCII string that you are using. Please see here for a possibly related issue, and here from a quick StackOverflow search.
Also, you are missing the newline ('\n') character in your str concatenation, although I don’t think this was the reason for your error above.