The sum of the list

a = [1,2,3]
b = [4,5,6]

Seeking a and b is added to the corresponding elements

1 a = [1,2,3]
2 b = [4,5,6]
3 for i in range(0,3):
4     print(a[i]+b[i])

But only for traversal achieved by adding only the corresponding elements, but the result is not a list:

It needs to be improved:

1 #方法一
2 a = [1,2,3]
3 b = [4,5,6]
4 ls = []
5 for i in range(0,3):
6     ls.append(a[i]+b[i])
7 print(ls)

 List of Formula

# Method II 
A = [l, 2,3 ] 
B = [4,5,6 ] 
LS = [I + J for (I, J) in ZIP (A, B)]     # for the front of a space, not a comma 
Print (LS)

 supplement:

(1) zip () usage:

zip (a, b) is a

Not a + b (this is only two splice list)

also can not:

1 a = [1,2,3]
2 b = [4,5,6]
3 for i in a:
4     for j in b:
5     print(i+j)

Because Layer cycle, after each traversed for the inner loop, only the outer layer out to a for loop. The case of i = 1, j = 4,5,6, rather than just equal to 4; when i = 2, then j = 4,5,6, rather than equal to 5