a = ["fred", "bo", "mary", "xiaobai"]
enumerate(a)
Out[3]: <enumerate at 0x3fa4318>


print enumerate(a)
<enumerate object at 0x0000000003FA4090>


for (x,y) in enumerate(a):
    print (x,y)
    
(0, 'fred')

(1, 'bo')

(2, 'mary')

(3, 'xiaobai')


for (w,t) in enumerate(a):
    print (w,t)
    
(0, 'fred')

(1, 'bo')

(2, 'mary')

(3, 'xiaobai')


z = enumerate(a)
print z
<enumerate object at 0x0000000003FA43F0>


for (index,item) in z:
    print index,item
    
0 fred

1 bo

2 mary

3 xiaobai


for (index,item) in z:
    print index,item
    
# note nothing is printed, we already used the generator z, it is empty