Failed to recognize comma on exec function on python2.7

Hi,

The parser does not recognize the comma on exec function with python2.7

I did try to create a PR solving this issue, I was doing a function " in_or_comma() " but I realized that the problem would be deeper than this because the visit_exec is treating the exec as a statement instead of function. Am I right?

Here it’s a small reproducible example of the error:

File: exec('x = 10' , {} )

Script:

import pasta
from pasta.augment import rename

path = r'test.py'

with open(path) as file:
        tree = pasta.parse(file.read())

Error:

pasta.base.annotate.AnnotationError: Expected 'in' but found ','
line 1: exec ('x = 10', {})

cc @nicoddemus

[williamjamir]

Just out of curiosity (I know it will not interfere with this problem), this different behavior occurred in the transition from Python 2.7.8 to 2.7.9

Checking the changelog I found this:

• Issue #21591: Correctly handle qualified exec statements in tuple form by moving compatibility layer from run-time to AST transformation.

[soupytwist]

Yes, I see the problem. I’ll need a more generic solution for this, it might also affect a few other places.

Generally, there needs to be support for when multiple children of a node can be parenthesized. Thanks for following up on it. I’ll start working on this when I get a chance.