How to get the number of same matches between two lists in Python?

Question

How do I extract the number of the same elements between two lists? Most of the answers I've searched for usually are related to finding common elements using set operation, but I'm looking for something like this:

list1 = [1, 2, 3, 4, 5, 6, 7, 8]
list2 = [1, 2, 3, 0, 0, 0, 0, 0]

The elements 1, 2, and 3 are the same, and so we return 3.

I understand that I could simply make a loop and increment a counter, but I'm wondering if there's any method that's more concise or efficient. Thanks in advance.

The accepted answer on the duplicate uses set intersection, but there are other answers which do not. — tripleee, Oct 22 '19 at 03:53
When you say "the same", do you mean in addition having the same value, they are also in the same position? — smac89, Oct 22 '19 at 03:54

score 1 · Answer 1 · answered Oct 22 '19 at 03:48

Try this:

print (sum(list1[i] == list2[i] for i in range(min(len(list1), len(list2)))))

Example

>>> list1 = [1, 2, 3, 4, 5, 6, 7, 8]
>>> list2 = [1, 2, 3, 0, 0, 0, 0, 0]
>>> print (sum(list1[i] == list2[i] for i in range(min(len(list1), len(list2)))))
3

score 1 · Answer 2 · answered Oct 22 '19 at 03:53

1

This works for me:

>>> list1 = [1, 2, 3, 4, 5, 6, 7, 8]
>>> list2 = [1, 2, 3, 0, 0, 0, 0, 0]
>>> sum( 1 for a,b in zip(list1,list2) if a == b )
3

Instead of sum() you may use len() -- same result.

answered Oct 22 '19 at 03:53

lenik

23,228
4
34
43

OP is asking for just the values to be the same, not necessarily their position – smac89 Oct 22 '19 at 03:58
1

@smac89 Yes, I mean positions that have the same element. Sorry for the confusion. – Sean Oct 22 '19 at 04:19

How to get the number of same matches between two lists in Python?

2 Answers2