operator.py

#sort a list of object based on an attribute or a method of the object

from operator import attrgetter, methodcaller

class Person(object):
    def __init__(self, name, age):
        self.age = age
        self.name = name


p1 = Person('Trijn', 101)
p2 = Person('Jaap', 45)
p3 = Person('Marie', 68)

l = [p1, p2, p3]

ls = sorted(l, key = attrgetter('age'))

for i in ls:
    print i.name