Lambdas

lambda_expr        ::=  "lambda" [parameter_list]: expression
lambda_expr_nocond ::=  "lambda" [parameter_list]: expression_nocond

Lambda expressions (sometimes called lambda forms) are used to create anonymous functions. The expression lambda arguments: expression yields a function object. The unnamed object behaves like a function object defined with

def <lambda>(arguments):
    return expression

See section Function definitions for the syntax of parameter lists. Note that functions created with lambda expressions cannot contain statements or annotations.