From 2f19e5d09825cf4b35843c54bf9ff0464cf35837 Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Thu, 6 Aug 2026 22:02:20 +0300 Subject: [PATCH] gh-74366: Fix the documentation of "$" in PyArg_ParseTupleAndKeywords() The keyword-only arguments are not always optional: they are required if "|" was not specified before "$". Document also that "|" cannot be specified after "$", and add examples for "|" and "$". --- Doc/c-api/arg.rst | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst index 58456a36b96c15..a878b20c928ea3 100644 --- a/Doc/c-api/arg.rst +++ b/Doc/c-api/arg.rst @@ -399,13 +399,18 @@ inside nested parentheses. They are: their default value --- when an optional argument is not specified, :c:func:`PyArg_ParseTuple` does not touch the contents of the corresponding C variable(s). + For example, the format string ``"OO|OO"`` corresponds to the Python + signature ``f(a, b, c=None, d=None)``. ``$`` :c:func:`PyArg_ParseTupleAndKeywords` only: Indicates that the remaining arguments in the Python argument list are - keyword-only. Currently, all keyword-only arguments must also be optional - arguments, so ``|`` must always be specified before ``$`` in the format - string. + keyword-only. + They are optional if ``|`` was specified before ``$``, and required otherwise. + ``|`` cannot be specified after ``$``. + For example, the format string ``"O|O$O"`` corresponds to the Python + signature ``f(a, b=None, *, c=None)``, + and the format string ``"OO$OO"`` corresponds to ``f(a, b, *, c, d)``. .. versionadded:: 3.3