"if PY{2,3} and X" doesn't ignore the X when run in other python version #3156
Description
Simple example:
from six import PY2
if PY2 and any({'foo': 'bar'}.iterkeys()): # error: Dict[str, str] has no attribute "iterkeys" when checking py3
pass
if PY2:
if any({'foo': 'bar'}.iterkeys()): # No error
pass
Note: The same thing applies to PY3 when run with --py2
Sometimes it's cumbersome to split it when you have a series of if, elif, else cases, like this:
if isinstance(node, ast.Name):
...
elif isinstance(node, ast.Num):
...
elif PY3 and isinstance(node, ast.Starred):
...
else:
// unhandled node type!