Clarify eval() doc from library/functions. (GH-22700)

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Antoine 2020-12-16 16:45:19 +01:00 committed by GitHub
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@ -478,14 +478,15 @@ are always available. They are listed here in alphabetical order.
dictionaries as global and local namespace. If the *globals* dictionary is
present and does not contain a value for the key ``__builtins__``, a
reference to the dictionary of the built-in module :mod:`builtins` is
inserted under that key before *expression* is parsed. This means that
*expression* normally has full access to the standard :mod:`builtins`
module and restricted environments are propagated. If the *locals*
dictionary is omitted it defaults to the *globals* dictionary. If both
dictionaries are omitted, the expression is executed with the *globals* and
*locals* in the environment where :func:`eval` is called. Note, *eval()*
does not have access to the :term:`nested scopes <nested scope>` (non-locals) in the
enclosing environment.
inserted under that key before *expression* is parsed. That way you can
control what builtins are available to the executed code by inserting your
own ``__builtins__`` dictionary into *globals* before passing it to
:func:`eval`. If the *locals* dictionary is omitted it defaults to the
*globals* dictionary. If both dictionaries are omitted, the expression is
executed with the *globals* and *locals* in the environment where
:func:`eval` is called. Note, *eval()* does not have access to the
:term:`nested scopes <nested scope>` (non-locals) in the enclosing
environment.
The return value is the result of
the evaluated expression. Syntax errors are reported as exceptions. Example: