gh-129515: Clarify syntax error messages for conditional expressions by sergey-miryanov · Pull Request #129880 · python/cpython · GitHub

Issue: Syntax error on '{z} if z is not None else pass' #129515

Along the suggestion from the original issue, I have added the following rules and messages:
The following expressions will be handled by a=disjunction 'if' b=disjunction 'else' c=invalid_ifexp_orelse_stmt and generate the message "Syntax Error: statement given where 'orelse' expression required" instead of just "Syntax Error: invalid syntax":

1 if True else pass
1 if True else return
1 if True else raise Exception('test')
1 if True else del smth
1 if True else yield 2
1 if True else assert False
1 if True else break
1 if True else continue

The following expressions will be handled by a=invalid_ifexp_body_stmt 'if' b=disjunction 'else' c=expression and generate the message "Syntax Error: statement given where 'body' expression required":

pass if True else 1
break if True else 1
continue if True else 1

The followingexpressions will be handled by a=invalid_ifexp_body_stmt 'if' b=disjunction 'else' c=invalid_ifexp_orelse_stmt and generate the message "Syntax Error: statement given where 'body' expression required":

pass if True else pass
break if True else continue

…sions

test_fstring fails, will dig

…y-miryanov/cpython into pythongh-129515-ifexp-syntax-error

Left some new comments

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

- also reword error messages - move tests to test_syntax - update whatsnew and news

I have made the requested changes; please review again

Thanks for making the requested changes!

@pablogsal: please review the changes made to this pull request.

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>

Ah, this looks MUCH better. Really well done @sergey-miryanov! 👍

…e-129515.3L3vmo.rst Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

…y-miryanov/cpython into pythongh-129515-ifexp-syntax-error

Thank you all for your review! I made the suggested changes, and it is ready now.

Excellent job @sergey-miryanov!

Thanks for your contribution 👌

Thanks!

pythongh-129515 : Clarify syntax error messages for conditional expres…

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…sions

sergey-miryanov requested review from Eclips4, lysnikolaou and pablogsal as code owners February 9, 2025 06:14

bedevere-app Bot added the awaiting review label Feb 9, 2025

bedevere-app Bot mentioned this pull request Feb 9, 2025

Syntax error on '{z} if z is not None else pass' #129515

Closed

sergey-miryanov commented Feb 9, 2025

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