[New-bugs-announce] [issue36798] := breaks f-strings

[Eric V. Smith]

New submission from Eric V. Smith <eric at trueblade.com>:

The walrus operator breaks f-strings, because the f-string scanner sees the colon as the end of the expression.

>>> x = '10'
>>> f'{x:=10}'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: '=' alignment not allowed in string format specifier

This becomes: format(x, '=10'), which is an error if x is a string.

----------
assignee: eric.smith
components: Interpreter Core
messages: 341413
nosy: eric.smith, larry, lukasz.langa
priority: release blocker
severity: normal
status: open
title: := breaks f-strings
versions: Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue36798>
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