using del in if clause confuses pyflakes

[David]

code:

----------------------------------------
test = True
if False:
    del(test)
assert(test)
----------------------------------------

pyflakes complains:
[...].py:4: undefined name 'test'

i guess this may be too hard for a static analysier, in which case, how about

----------------------------------------
test = True
if False:
    del(test)
else:
    assert(test)
----------------------------------------

where the usage is in a different else branch to the del

output:
[...].py:5: undefined name 'test'

[Jean-Paul Calderone (exarkun)]

You're welcome to give it a try.

[Marcin Cieślak (saperski)]

I have a code in https://github.com/kevinw/pyflakes/pull/28
(https://github.com/saper/pyflakes/commit/09c52fcfab742b4f67c9d21d18ae389c300b4ea6) to fix another bug https://bugs.launchpad.net/pyflakes/+bug/916264 but there is a code to detect if instructions are on different sides
of "if:" and "else:" or "try:/except:/else:". I think this approach could be applied to this case as well.

More info about how it works here:

https://code.launchpad.net/~dobey/divmod.org/pyflakes-less-redef/+merge/130183/comments/307409

[Florent (florent.x)]

bug #885140 marked as duplicate of this one

[Florent (florent.x)]

bug #1212912, actually

[Adi Roiban (adiroiban)]

Here is my attempt to fix this https://github.com/pyflakes/pyflakes/pull/12

Please take a look. Thanks!