Common elements between two lists not using sets in Python

Question

I want count the same elements of two lists. Lists can have duplicate elements, so I can\'t convert this to sets and use & operator.

a=[2,2,1,1]
b=[1,1,3         


        

Answer 1

SilentGhost, Mark Dickinson and Lo'oris are right, Thanks very much for report this problem - I need common part of lists, so for:

a=[1,1,1,2]

b=[1,1,3,3]

result should be [1,1]

Sorry for comment in not suitable place - I have registered today.

I modified yours solutions:

def count_common(l1,l2):
        l2_copy=list(l2)
        counter=0
        for i in l1:
            if i in l2_copy:
                counter+=1
                l2_copy.remove(i)
        return counter

l1=[1,1,1]
l2=[1,2]
print count_common(l1,l2)

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1