iter() sample

the iter() is more like generator, it will return an item every time you call it. here is the different output by using list and iter()

it = range(10)
print it
b = zip(it, it)
print b

it = iter(range(10))
b = zip(it, it)
print b

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
[(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6), (7, 7), (8, 8), (9, 9)]
[(0, 1), (2, 3), (4, 5), (6, 7), (8, 9)]