Sorting class instances in python

Question

What does python 2.7 use to sort vanilla class instances? I\'m interested in the default sorting behavior.

Suppose I have the class

class S():
    pa         


        

Answer 1

Python's sort algorithm exclusively compares items using a "less than" test, which can be implemented either using the __cmp__() special method (now deprecated) or __lt__() on the class.

In the absence of any specific instruction on how to compare two objects, the id() is used (not the hash) for objects of the same type, as in your case.