Certain classes of identifiers (besides keywords) have special
meanings. These classes are identified by the patterns of leading and
trailing underscore characters:
Not imported by "from module import *". 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 section 6.12, ``The import statement.''
The name "_" is often used in conjunction with
internationalization; refer to the documentation for the
gettext module for more
information on this convention.
System-defined names. These names are defined by the interpreter
and its implementation (including the standard library);
applications should not expect to define additional names using this
convention. The set of names of this class defined by Python may be
extended in future versions.
See section 3.4, ``Special method names.''
Class-private names. Names in this category, when used within the
context of a class definition, are re-written to use a mangled form
to help avoid name clashes between ``private'' attributes of base
and derived classes.
See section 5.2.1, ``Identifiers (Names).''