PEP 8 says: “If your public attribute name collides with a reserved keyword, append a single trailing underscore to your attribute name.  This is preferable to an abbreviation or corrupted spelling.” e.g. “class_” is used for an HTML class. “(However, notwithstanding this rule, 'cls' is the preferred spelling for any variable or argument which is known to be a class, especially the first argument to a class method.)” I’d like this recommendation to be followed, even if it’s in an internal function.