2.3.2 Reserved classes of identifiers
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.''
Note: The name "_"
is often used in conjunction with internationalization; refer to the documentation for
module for more information on this convention.
- System-defined names. These names are defined by the interpreter and it's
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 3.3, ``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 for to help avoid name clashes between
``private'' attributes of base and derived classes. See section 5.2.1, ``Identifiers (Names).''