Get difference between two lists with Unique Entries
list, performance, python, set, set-difference
Solution
To get elements which are in `temp1` but not in `temp2` (assuming uniqueness of the elements in each list):
In [5]: list(set(temp1) - set(temp2))
Out[5]: ['Four', 'Three']
Beware that it is asymmetric :
In [5]: set([1, 2]) - set([2, 3])
Out[5]: set([1])
where you might expect/want it to equal `set([1, 3])`. If you do want `set([1, 3])` as your answer, you can use `set([1, 2]).symmetric_difference(set([2, 3]))`.
Problem
I have two lists in Python: ``` temp1 = ['One', 'Two', 'Three', 'Four'] temp2 = ['One', 'Two'] ``` Assuming the elements in each list are unique, I want to create a third list with items from the first list which are not in the second list: ``` temp3 = ['Three', 'Four'] ``` Are there any fast ways without cycles and checking?