Flask 2.0 uses implicit reexports which mypy complains about

[scottbelden]

Now that flask 2.0.0 has a py.typed file, the flask types are preferred over the typeshed hints. When running mypy on my code, I now see errors like the following:

 app.py:6: error: Module 'flask' does not explicitly export attribute 'Flask'; implicit reexport disabled
 app.py:6: error: Module 'flask' does not explicitly export attribute 'render_template'; implicit reexport disabled
 app.py:6: error: Module 'flask' does not explicitly export attribute 'request'; implicit reexport disabled
 app.py:6: error: Module 'flask' does not explicitly export attribute 'flash'; implicit reexport disabled
 app.py:6: error: Module 'flask' does not explicitly export attribute 'send_file'; implicit reexport disabled

In flask/__init__.py there are lines like this:

flask/src/flask/__init__.py

Line 7 in d575de5

from .app import Flask

However, mypy expects that these reexports should either have an __all__ to explicitly say which variables are being reexported, or to change the import to from .app import Flask as Flask

In typeshed there is an example of how this was done before flask including typing: https://github.com/python/typeshed/blob/6bb1d885c696914e5900329c3d0b6bf2bfefee81/stubs/Flask/flask/__init__.pyi

Environment:

• Python version: 3.9
• Flask version: 2.0.0

[davidism]

Duplicate of pallets/jinja#1426

See python/mypy#10198 for discussion on changing this behavior.