New submission from Michael Cuthbert <cuthb...@mit.edu>:
The What's New in Python 3.10 docs demonstrates a richer SyntaxError for this
set comprehension:
>>> {x,y for x,y in range(100)}
File "<stdin>", line 1
{x,y for x,y in range(100)}
^
SyntaxError: did you forget parentheses around the comprehension target?
The problem (at least for beginners) is that there are two errors in the line.
Parenthesizing the comprehension target gets "TypeError: cannot unpack
non-iterable int object" since "x,y in range(...)" does not work. I think it
would be better to illustrate with code that works if not for the missing
parentheses. Something like this:
>>> {x,y for x,y in zip('abcd', 'efgh')}
File "<stdin>", line 1
{x,y for x,y in zip('abcd', 'efgh')}
^
SyntaxError: did you forget parentheses around the comprehension target?
Thanks for the great work on making error messages better! This prof. who often
has to help students with Python errors heartily approves!
----------
assignee: docs@python
components: Documentation
messages: 393704
nosy: docs@python, mscuthbert
priority: normal
severity: normal
status: open
title: Unparenthesized tuple doc bug in what's new
type: behavior
versions: Python 3.10
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Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue44139>
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