Certain classes of identifiers (besides keywords) have special
meanings. These are:
Form
Meaning
Notes
_*
Not imported by "from module import *"
(1)
__*__
System-defined name
__*
Class-private name mangling
(XXX need section references here.)
Note:
(1)
The special identifier "_" is used in the interactive
interpreter to store the result of the last evaluation; it is stored
in the __builtin__ module. When not in interactive mode,
"_" has no special meaning and is not defined.