Python compare words and remove duplicates in two list of lists-CodePudding

I have the following lists:

list_1_test = [['hi','there','how'],['we','are','one']]
list_2_test = [['hi','you','how'],['we','not','one']]

I wish to compare the words in the list and get the following output:

list_3_test = [['there','you'],['are','not']]

I know how to do this in a simple list, for example:

list_1_test = ['hi','there','how']
list_2_test = ['hi','you','how']

list_3_test=[]
for i in list_1_test:
    if i not in list_2_test:
        list_3_test.append(i)

for i in list_2_test:
    if i not in list_1_test:
        list_3_test.append(i)

and the result is

['there', 'you']

But when it comes to list of lists, my brain is fried. The order matters. Any help is much appreciated.

CodePudding user response：

If order doesn't matter, you can use set operations list comprehension:

out = [list(set(l1).union(l2) - set(l1).intersection(l2)) for l1, l2 in zip(list_1_test, list_2_test)]

Output:

[['you', 'there'], ['are', 'not']]

If order matters, you can use dict.fromkeys:

out = []
for l1, l2 in zip(list_1_test, list_2_test):
    one = dict.fromkeys(l1).keys()
    two = dict.fromkeys(l2).keys()
    out.append(list(one - two)   list(two - one))

Output:

[['there', 'you'], ['are', 'not']]

CodePudding user response：

You can use the sets and symetric_difference method (^):

list3 = []
for l1, l2 in zip(list_1_test, list_2_test):
    sym_dif = set(l1)^set(l2)
    list3.append(list(sym_dif))

Previous code in list comprehension format:

list3 = [set(l1)^set(l2) for l1, l2 in zip(list_1_test, list_2_test)]