Name mangling occurs during the evaluation of a class statement. In the case of Bar, the __cache attribute is not defined as part of the class, but rather added to a specific object after the fact. (Actually, that may not be entirely correct. Name mangling may occur during the evaluation of the __new__ method; I … Read more
From the Python PEP 8 — Style Guide for Python Code: Descriptive: Naming Styles The following special forms using leading or trailing underscores are recognized (these can generally be combined with any case convention): _single_leading_underscore: weak “internal use” indicator. E.g. from M import * does not import objects whose name starts with an underscore. single_trailing_underscore_: … Read more
In C, symbols starting with an underscore followed by either an upper-case letter or another underscore are reserved for the implementation. You as a user of C should not create any symbols that start with the reserved sequences. In C++, the restriction is more stringent; you the user may not create a symbol containing a … Read more