Django 2.0へのアップデート (Removed support for bytestrings編) ref: https://qiita.com/tnir/items/27a9ecd20c7c7f2e9aee

file0.txt

>>> from polls.models import Choice
>>> bytes_text = some_func() # => b'Just hacking'
>>> Choice(choice_text=str(bytes_text)).save()
>>> Choice.objects.filter(choice_text=bytes_text) # => NG
<QuerySet []>
>>> Choice.objects.filter(choice_text=bytes_text.decode()) # => OK
<QuerySet [<Choice: Just hacking>]>

file1.txt

python manage.py test

file2.txt

python -bb manage.py test