2011/10/22 Know Your Time Complexities

• by Ryan J. O’Neil
• rzoz on #pylaides

Whole bunch of data

Remove duplicates from a large system and remove dupes

import random

choices = range(100000)
x = [random.choice(choices) for i in xrange(1000000)]

The Bad Way

order = []
for i in x:
    if i not in order:
        order.append(i)

The Good Way

order = []
seen = set()
for i in x:
    if i not in seen:
        seen.add(i)
        order.append(i)