Short timing example between dict, list and set in python.

test.py

from time import time
from random import random

# Without checking the dictionary
x = {}
s = time()
for i in range(10000000):
    x[round(random(), 6)] = True
e = time()
print(e-s, len(x), 'Using dict() for inserts')

s = time()
for i in range(10000000):
    if i in x: pass
e = time()
print(e-s, 'dict() time spent looking through the data')

# Using set()
x = set()
s = time()
for i in range(10000000):
    num = round(random(), 6)
    if not num in x:
        x.add(num)
e = time()
print(e-s, len(x), 'Using set() for inserts')

s = time()
for i in range(10000000):
    if i in x: pass
    e = time()
print(e-s, 'set() time spent looking through the data')

# Using lists
x = []
s = time()
for i in range(10000000): # Half the ammount 5M instead of 10M
    num = round(random(), 6)
    if not num in x:
        x.append(num)
e = time()
print(e-s, len(x), 'Using list()')