classification
Title: AST unparsing of infinity numbers
Type: behavior Stage:
Components: Interpreter Core Versions: Python 3.8, Python 3.7
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: gvanrossum, lukasz.langa, serhiy.storchaka
Priority: normal Keywords:

Created on 2018-02-21 12:20 by serhiy.storchaka, last changed 2018-02-21 12:20 by serhiy.storchaka.

Messages (1)
msg312492 - (view) Author: Serhiy Storchaka (serhiy.storchaka) * (Python committer) Date: 2018-02-21 12:20
AST unparsing of infinity numbers produces a string which can't be evaluated because inf and infj are not builtins.

>>> from __future__ import annotations
>>> def f(x: A[1e1000, 1e1000j]): pass
... 
>>> f.__annotations__
{'x': 'A[(inf, infj)]'}

See how this problem is handled in Tools/parser/unparse.py.

There is similar problem with NaN. NaN can't be a result of parsing Python sources, but it can be injected manually in AST, and it can be a result of third-party AST optimizer.
History
Date User Action Args
2018-02-21 12:20:59serhiy.storchakacreate