Compare elements in two lists in python

Question

I have two lists as below:

a = ['abc','def', 'ghi'], b=['ZYX','WVU']

and want to confirm whether union of both lists is equal to superset

c = ['ZYX', 'def', 'WVU', 'ghi', 'abc']

I have tried following:

>>> print (c == list(set(b).union(c)))
>>> False

Can anybody show what I am missing here?

Mihai Alexandru-Ionut · Accepted Answer · 2018-05-05T06:37:41.953

2

Just use set method because the items order in the lists are different and that's why you've received False as result.

print (set(c) == set(list(set(b).union(c))))

Another solution is to use Counter class. The Counter approach should be more efficient for big lists since it has linear time complexity (i.e. O(n))

from collections import Counter
Counter(c) == Counter(list(set(b).union(c))))

edited May 05 '18 at 06:37

answered May 05 '18 at 06:21

Mihai Alexandru-Ionut

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...or use sets on both side to spare the expensive sorting. – Klaus D. May 05 '18 at 06:24
Thank you. I missed `set` method. I can `print (set(c) == set(b).union(c))` too. – abhi1610 May 05 '18 at 06:29
@abhi1610, you're welcome. You can also use `Counter` method as in my answer. – Mihai Alexandru-Ionut May 05 '18 at 06:33

Compare elements in two lists in python

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