2.3.2 保留的标识符类型 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.''
不能通过" from moduls import *"导入。
特定标识符"_"在交互式解释器用于存储上次估值的结果. 它位于__buildin__模块之中. 在非交互方式时,"_"没有特殊含义, 且是未定义的
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 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).''