enumerate

e.g.

t = [1, 3, 7, 10]

for e in enumerate(t):
    print(e) #튜플 형대로 반환

for i, e in enumerate(t):
    print(i, e)

출력

(0,1)
(1,3)
(2,7)
(3,10)

0 1
1 3
2 7
3 10