Module does not explicitly export attribute [attr-defined]

In bar.py foo is imported

# bar.py
from path import foo

In my current file bar is imported and I use the get_id function of foo:

from path import bar
bar.foo.get_id()

Mypy is complaining

error: Module "bar" does not explicitly export attribute "foo"  [attr-defined]

Solution

Is it your own module?

Use one of these two options that are suggested in the mypy docs; the __all__ is generally preferred

# This will re-export it as bar and allow other modules to import it
from foo import bar as bar

# This will also re-export bar
from foo import bar
__all__ = ['bar']

If its a 3rd party; but also valid for your on modules

Not all modules are designed and follow these suggestions you can disable/not check for the error, but first check:

Is is more valid to use foo directly?
```
from path import foo
foo.get_id()
```
I argue that the usage of module.non_child_module.function is often not justified. Also when writing your own modules it's more likely to create import-cycles when you put an unnecessary intermediate module in between.
If you think keeping bar.foo is more valid than using foo directly you can either add a # type: ignore[attr-defined]
Do not check for the error at all and use --no-implicit-reexport / implicit_reexport=False as many modules