Get difference between two lists

Question

I have two lists in Python, like these:

temp1 = [\'One\', \'Two\', \'Three\', \'Four\']
temp2 = [\'One\', \'Two\']

I need to create a third

Answer 1

You could use a naive method if the elements of the difflist are sorted and sets.

list1=[1,2,3,4,5]
list2=[1,2,3]

print list1[len(list2):]

or with native set methods:

subset=set(list1).difference(list2)

print subset

import timeit
init = 'temp1 = list(range(100)); temp2 = [i * 2 for i in range(50)]'
print "Naive solution: ", timeit.timeit('temp1[len(temp2):]', init, number = 100000)
print "Native set solution: ", timeit.timeit('set(temp1).difference(temp2)', init, number = 100000)

Naive solution: 0.0787101593292

Native set solution: 0.998837615564