Core Python Programming

6.12. Built-in Functions

6.12.1. Standard Type Functions

cmp()

In Section 4.6.1, we introduced the cmp() built-in function with examples of comparing numbers and strings. But how would cmp() work with other objects such as lists and tuples, which can contain not only numbers and strings, but other objects like lists, tuples, dictionaries, and even user-created objects?

>>> list1, list2 = [123, 'xyz'], [456, 'abc']
>>> cmp(list1, list2)
-1
>>>
>>> cmp(list2, list1)
1
>>> list3 = list2 + [789]
>>> list3
[456, 'abc', 789]
>>>
>>> cmp(list2, list3)
-1

Compares are straightforward if we are comparing two objects of the same type. For numbers and strings, the direct values are compared, which is trivial. For sequence types, comparisons are somewhat ...