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Stick with the phrase "default parameter value" (GH-21590)

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Andre Delfino 2020-07-22 20:58:19 -03:00 • committed by GitHub
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Doc/reference/compound_stmts.rst
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@ -571,9 +571,9 @@ value --- this is a syntactic restriction that is not expressed by the grammar.
**Default parameter values are evaluated from left to right when the function **Default parameter values are evaluated from left to right when the function
definition is executed.** This means that the expression is evaluated once, when definition is executed.** This means that the expression is evaluated once, when
the function is defined, and that the same "pre-computed" value is used for each the function is defined, and that the same "pre-computed" value is used for each
call. This is especially important to understand when a default parameter is a call. This is especially important to understand when a default parameter value is a
mutable object, such as a list or a dictionary: if the function modifies the mutable object, such as a list or a dictionary: if the function modifies the
object (e.g. by appending an item to a list), the default value is in effect object (e.g. by appending an item to a list), the default parameter value is in effect
modified. This is generally not what was intended. A way around this is to use modified. This is generally not what was intended. A way around this is to use
``None`` as the default, and explicitly test for it in the body of the function, ``None`` as the default, and explicitly test for it in the body of the function,
e.g.:: e.g.::