Undefined name detected in `__all__`PYL-E0603

__all__ is a list of strings defining what objects in a module will be exported when from <module> import * is used on the module. Hence, all the object names mentioned in __all__ shall be defined in the module.

This issue is raised because __all__ contains atleast one name (See issue title for the exact name) which is not defined in the module. When a wildcard import is attempted on the module with this guilty code, Python will throw an AttributeError while trying to import the undefined object.

Here is an example:

guilty.py

def my_awesome_function():
    print("This is my awesome function.")

__all__ = ["my_awesome_function", "something_undefined"]

foo.py

from guilty import *

my_awesome_function()

When foo.py is run, Python will throw this error: AttributeError: module 'guilty' has no attribute 'something_undefined'

Note: During autofixing this issue, DeepSource will remove all the undefined name. If the there's a missing comma which implicitly concatenate the names, DeepSource will separate all the concatenated strings.

Bad practice

In the following snippet, connection and frame is undefined. There's also a missing comma between predict and "ClearMap".

...
__all__ = ["connection", "predict" "ClearMap", "frame"]

Recommended

The autofix will remove undefined connection and frame and add a comma between predict and "ClearMap".

...
__all__ = ["predict", "ClearMap"]