gh-153568: Don't materialize parser token text that is never read#153576
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pablogsal wants to merge 2 commits into
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gh-153568: Don't materialize parser token text that is never read#153576pablogsal wants to merge 2 commits into
pablogsal wants to merge 2 commits into
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Only tokens whose text is actually consumed get a bytes object; operators and structural tokens no longer allocate one.
maurycy
reviewed
Jul 11, 2026
Co-authored-by: Maurycy Pawłowski-Wieroński <maurycy@maurycy.com>
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The parser created a bytes object for every token, but only identifiers, keywords, numbers, strings and type comments ever have their text read. Operators and structural tokens now skip the allocation entirely.
Benchmark (parsing 8 of the largest stdlib files, 1.3 MB, 20 times per run with
_PyParser_ASTFromString— parser only, no AST-to-Python conversion; pyperf, interleaved runs):