From af5a862e65c6f4633e099c5edf259a2072a6d2e2 Mon Sep 17 00:00:00 2001 From: Jake Wallin Date: Tue, 20 Oct 2026 01:39:44 +0000 Subject: [PATCH] gh-156675: Exclude annotations from the documented lambda grammar --- Doc/reference/expressions.rst | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst index 2e0b6621eb11c8..153f51edaae790 100644 --- a/Doc/reference/expressions.rst +++ b/Doc/reference/expressions.rst @@ -2440,7 +2440,16 @@ Lambdas single: : (colon); lambda expression .. productionlist:: python-grammar - lambda_expr: "lambda" [`parameter_list`] ":" `expression` + lambda_expr: "lambda" [`lambda_parameter_list`] ":" `expression` + lambda_parameter_list: `lambda_defparameter` ("," `lambda_defparameter`)* "," "/" ["," [`lambda_parameter_list_no_posonly`]] + : | `lambda_parameter_list_no_posonly` + lambda_parameter_list_no_posonly: `lambda_defparameter` ("," `lambda_defparameter`)* ["," [`lambda_parameter_list_starargs`]] + : | `lambda_parameter_list_starargs` + lambda_parameter_list_starargs: "*" `identifier` ("," `lambda_defparameter`)* ["," [`lambda_parameter_star_kwargs`]] + : | "*" ("," `lambda_defparameter`)+ ["," [`lambda_parameter_star_kwargs`]] + : | `lambda_parameter_star_kwargs` + lambda_parameter_star_kwargs: "**" `identifier` [","] + lambda_defparameter: `identifier` ["=" `expression`] Lambda expressions (sometimes called lambda forms) are used to create anonymous functions. The expression ``lambda parameters: expression`` yields a function @@ -2451,9 +2460,9 @@ object. The unnamed object behaves like a function object defined with: def (parameters): return expression -See section :ref:`function` for the syntax of parameter lists. Note that -functions created with lambda expressions cannot contain statements or -annotations. +The rules for parameter lists are the same as for :ref:`function definitions +`, except that annotations are not allowed. Functions created with +lambda expressions cannot contain statements or annotations. .. index::