Py keyword takes precedence over identifier with the same name

[mark-koch]

What happens if I write

@guppy
def f() -> int:
    py = lambda x: x+1
    return py(2)

?

_Originally posted by @aborgna-q in https://github.com/CQCL/guppylang/pull/515#discussion_r1782506340_

[mark-koch]

In see two options:

• Turn py into an actual function and use a CustomCallChecker
• Disallow naming variables py since it's a "keyword"

[aborgna-q]

I'd say option 1 is the more pythonic. There are no function keywords in python3. From a user perspective, if you can shadow print you should be able to do the same with py.