2.3.2 Reserved classes of identifiers

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

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.

See About this document... for information on suggesting changes.