➜
This issue tracker has been migrated to GitHub,
and is currently read-only.
For more information,
see the GitHub FAQs in the Python's Developer Guide.
Created on 2017-11-14 10:25 by ncoghlan, last changed 2022-04-11 14:58 by admin. This issue is now closed.
| Pull Requests | |||
|---|---|---|---|
| URL | Status | Linked | Edit |
| PR 4400 | merged | serhiy.storchaka, 2017-11-15 08:53 | |
| Messages (2) | |||
|---|---|---|---|
| msg306197 - (view) | Author: Alyssa Coghlan (ncoghlan) *  |
Date: 2017-11-14 10:25 | |
The compiler currently allows parentheses to be omitted if a generator expression is the sole entry in a base class list:
>>> class C(x for x in []): pass
...
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: cannot create 'generator' instances
The language reference states that the parentheses around a generator expression are only optional for "calls with only one argument": https://docs.python.org/3/reference/expressions.html#generator-expressions
A base class list is not a call, so this should be treated as a syntax error, rather than being handled as equivalent to `class C((x for x in [])): pass`
|
|||
| msg306275 - (view) | Author: Serhiy Storchaka (serhiy.storchaka) * |
Date: 2017-11-15 15:39 | |
New changeset ddbce1378644f9d5ad0651e1c9035bd8c6502edc by Serhiy Storchaka in branch 'master': bpo-32023: Disallow genexprs without parenthesis in class definitions. (#4400) https://github.com/python/cpython/commit/ddbce1378644f9d5ad0651e1c9035bd8c6502edc |
|||