Get only unique elements from two lists

Question

If I have two lists (may be with different len):

x = [1,2,3,4] f = [1,11,22,33,44,3,4]  result = [11,22,33,44] 

im doing:

for element in f:     if element in x:         f.remove(element) 

I'm getting

result = [11,22,33,44,4] 

Answer 1

UPDATE:

Thanks to @Ahito:

In : list(set(x).symmetric_difference(set(f)))  Out: [33, 2, 22, 11, 44] 

This article has a neat diagram that explains what the symmetric difference does.

OLD answer:

Using this piece of Python's documentation on sets:

>>> # Demonstrate set operations on unique letters from two words ... >>> a = set('abracadabra') >>> b = set('alacazam') >>> a                                  # unique letters in a {'a', 'r', 'b', 'c', 'd'} >>> a - b                              # letters in a but not in b {'r', 'd', 'b'} >>> a | b                              # letters in a or b or both {'a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'} >>> a & b                              # letters in both a and b {'a', 'c'} >>> a ^ b                              # letters in a or b but not both {'r', 'd', 'b', 'm', 'z', 'l'} 

I came up with this piece of code to obtain unique elements from two lists:

(set(x) | set(f)) - (set(x) & set(f)) 

or slightly modified to return list:

list((set(x) | set(f)) - (set(x) & set(f))) #if you need a list 

Here:

1. | operator returns elements in x, f or both
2. & operator returns elements in both x and f
3. - operator subtracts the results of & from | and provides us with the elements that are uniquely presented only in one of the lists