OddOccurrencesInArray 2 python

// find element without pair in array
def solution(A):
    A.sort()
    for index in range(0,len(A),2):
        if A[index] != A[index+1]:
            return A[index]
B = [5,6,2,9,2,3,6,7,3,1,7,9,1]
print(solution(B))

Hey, I don't know whether you have modified yours or not but I have tried to modified yours and it is now giving 100% correct result according to codility

def solution(A):
A.sort()
for index in range(0,len(A),2):
boundary = len(A)-2
if index <boundary:
if A[index] != A[index+1]:
return A[index]
else:
return A[-1]

cheers !!! happy coding

from collections import Counter

def solution(A):

oc  = Counter(A)
for o in oc.keys():
    if oc[o] % 2 ==1:
        return o

Hey, I don't know whether you have modified yours or not but I have tried to modified yours and it is now giving 100% correct result according to codility

def solution(A):
A.sort()
for index in range(0,len(A),2):
boundary = len(A)-2
if index <boundary:
if A[index] != A[index+1]:
return A[index]
else:
return A[-1]

cheers !!! happy coding

Can you explain to me?