Old-style classes are those declared without a parent
class, or classes that inherit from an existing old-style
Here is an outline of the birth, life, and death of an
old-style class and its instances.
Section 26.1.1, “Defining an old-style class”.
Section 26.1.2, “Instantiation of an old-style class: The
Section 26.1.3, “Attribute references in old-style classes”.
Section 26.1.4, “Method calls in an old-style class”.
Section 26.1.5, “Instance deletion: the destructor, .__del__()”.