diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst index a8a4ca42007..24dc65d563c 100644 --- a/Doc/library/functions.rst +++ b/Doc/library/functions.rst @@ -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 ` (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 ` (non-locals) in the enclosing + environment. The return value is the result of the evaluated expression. Syntax errors are reported as exceptions. Example: