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Update the grammar for f-strings on "Lexical analysis" page #116580
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I'm not sure whether this is the way to go.
The full grammar specification is generated from the grammar file itself (although stripped down quite a bit).In the lexical analysis page, there's grammars for many different syntactic constructs of the language that are directed to humans and are written in a way that should reflect that. They're also all consistent in the syntax they use, so changing only one place and have it written in PEG feels a bit odd.
If all you care about is being able to link to the f-string grammar for other people to read, then that grammar in the lexical analysis page is certainly good enough and covers what the real PEG grammar should be able to cover as well. If you want to link to the real grammar that's used at runtime, linking to https://github.com/python/cpython/blob/main/Grammar/python.gram#L912-L927 is probably good enough?
Yeah, I'm giving a bit of time each week to generating docs from the actual grammar, and hope to do it by 3.13. But i want to look at f-strings (and other topics that need touch lexical docs) last.
They're also all consistent in the syntax they use, so changing only one place and have it written in PEG feels a bit odd.
Yeah, I agree. I wasn't aware of that.
If you want to link to the real grammar that's used at runtime, linking to
main/Grammar/python.gram#L912-L927 is probably good enough?It should be good enough although I would still prefer have it link to the language reference to include any contextual information as well.
@encukou Thank you! If there's a tracking issue for the same, we can merge this into it otherwise I leave it at your discretion to keep this open or not. I'm fine closing it.
No issue yet, just discussion.
I'll assign this to myself: it might be a few months before I get to this, but do talk to me if you want to start working on it earlier :)Reacted by Dhruv Manilawala- linked a pull request that will close this issuegh-135676: Reword the f-string (and t-string) section #137469
on Aug 22, 2025
Documentation
Apologies if this is tracked somewhere else, I couldn't find it.
I'm looking at the f-string section in the "Lexical analysis" page and the grammar is not yet updated with the implementation of PEP 701: https://docs.python.org/3.12/reference/lexical_analysis.html#formatted-string-literals while it is so on the "Full Grammar specification" page: https://docs.python.org/3.13/reference/grammar.html.
The main use case for this is to link to the f-string grammar. It's difficult to do so on the "Full Grammar specification" page but it's easy on an individual section.