ImportError: cannot import name 'want_bytes' from 'itsdangerous'

[bschley]

I started a new project with Flask-Session, which raises ImportError: cannot import name 'want_bytes' from 'itsdangerous' (c:\python37\lib\site-packages\itsdangerous\__init__.py).

Traceback (most recent call last):
  File "c:\python37\lib\site-packages\flask\cli.py", line 235, in locate_app
    __import__(module_name)
  File "C:\Users\PC\Desktop\BookLib\application.py", line 4, in <module>
    from flask_session import Session
  File "c:\python37\lib\site-packages\flask_session\__init__.py", line 16, in <module>
    from .sessions import NullSessionInterface, RedisSessionInterface, \
  File "c:\python37\lib\site-packages\flask_session\sessions.py", line 23, in <module>
    from itsdangerous import Signer, BadSignature, want_bytes
ImportError: cannot import name 'want_bytes' from 'itsdangerous' (c:\python37\lib\site-packages\itsdangerous\__init__.py)

The quick fix I did was to downgrade to the previous version, itsdangerous==0.24.

[davidism]

Duplicate of #108, pallets-eco/flask-session#89, pallets/flask#2952

[davidism]

itsdangerous 1.1.0 was just released and contains a fix for this. Flask-Session should still be fixed so it doesn't rely on this, but it won't fail for now. You can upgrade itsdangerous and continue to use Flask-Session.