Unreported undefined name in __all__

[adhikasp]

Pyflakes was unable to detect undefined name in __all__ when there exist undefined name outside of it. This make me need to use pyflakes 2 times to really detect all the errors.

For example, given this code...

from math import * # contain sin, cos, and csc
__all__ = ['sin', 'cos']
csc(1)

Pyflakes will report

test.py:1: 'from math import *' used; unable to detect undefined names
test.py:5: 'csc' may be undefined, or defined from star imports: math

According to that, the code just have 2 "error", which is usage of * import and csc is undefined.
If I then fix the code

from math import csc
__all__ = ['sin', 'cos']
csc(1)

Then additional error shown up

test.py:3: undefined name 'cos' in __all__
test.py:3: undefined name 'sin' in __all__

Which then could finally fixed by

from math import csc, cos, sin
__all__ = ['sin', 'cos']
csc(1)

[bitglue]

What behavior do you expect? import * could import anything, so what could pyflakes do better than what it does now?

[asmeurer]

He is saying there should be similar messages for sin and cos as the csc message.

[adhikasp]

@bitglue I was expecting that if pyflakes do want to report about that 2 kind of error, do it at the same time, not when the other issue was already gone (issue hidden at first sight)

[bitglue]

It's "hidden" because pyflakes can't know what * imports. It's not until you explicitly declare what's in the namespace that pyflakes can tell you what's not in it.