1、迭代器使用itertools
2、迭代器的属性包括：
3、使用itertools.product()生成参数：
import itertools
a = (1, 2, 3)
b = (‘A’, ‘B’, ‘C’)
c = itertools.product(a,b)
for elem in c:
print elem
(1, ‘A’)
(1, ‘B’)
(1, ‘C’)
(2, ‘A’)
(2, ‘B’)
(2, ‘C’)
(3, ‘A’)
(3, ‘B’)
(3, ‘C’)
