Methods are functions that are called using the attribute notation.
There are two flavors: built-in methods (such as
lists) and class instance methods. Built-in methods are described
with the types that support them.
The implementation adds two special read-only attributes to class
m.im_self is the object whose method this
m.im_func is the function implementing the method.
m(arg-1, arg-2, ...,
arg-n) is completely equivalent to calling
m.im_func(m.im_self, arg-1, arg-2,
(See the Python Reference Manual for more info.)