Python min function with a list of objects

Question

How can use the key argument for the min function to compare a list of objects\'s 1 attribute?

Example

class SpecialNumber:         


        

Answer 1

the getattr version is faster

import random
from operator import attrgetter

class Test:
    def __init__(self):
        self.a = random.random()

t = [Test() for i in range(10000)]

%timeit min(t, key=lambda x: x.a)
1000 loops, best of 3: 790 µs per loop

%timeit min(t,key=attrgetter('a'))
1000 loops, best of 3: 582 µs per loop