Help in understanding a line in python 3 solution provided


#1

class Solution:
# @param A : tuple of integers
# @return an integer
def hammingDistance(self, A):
array=[]
total=0
for i in A:
array.append(’{0:032b}’.format(i))
array=list(zip(*array))
for i in array:
a=i.count(“0”)
**

total+=2a(len(i)-a)

**
return total%1000000007

can someone explain how this particular line of the code works in the python 3 solution provided
how is the total calculated ?
total+=2a(len(i)-a)