Python 2 includes a cmp function which allows you to determine if one object is less than, equal to, or greater than another object. This function can be used to pick a choice out of a list based on one of those three options.

Suppose you need to print 'greater than' if x > y, 'less than' if x < y and 'equal' if x == y.

['equal', 'greater than', 'less than', ][cmp(x,y)]

# x,y = 1,1 output: 'equal'
# x,y = 1,2 output: 'less than'
# x,y = 2,1 output: 'greater than'

cmp(x,y) returns the following values

| Comparison | Result |
|————|––––|
| x \\< y | -1 |
| x == y | 0 |
| x > y | 1 |

This function is removed on Python 3. You can use the [cmp_to_key(func)](<https://docs.python.org/3/library/functools.html#functools.cmp_to_key>) helper function located in [functools](<http://stackoverflow.com/documentation/python/2492/functools#t=201608152305056538775>) in Python 3 to convert old comparison functions to key functions.