避免嵌套的for循环

使用方法

product

x1 = xrange(min1,max1,step1)x2 = xrange(min2,max2,step2)x3 = xrange(min3,max3,step3)...for v1, v2, v3, v4, v5, v6 in itertools.product(x1, x2, x3, x4, x5, x6):    icky_thing(....)

或更紧凑：

ranges = [    xrange(min1,max1,step1),    xrange(min2,max2,step2),    xrange(min3,max3,step3),    ...]for v1, v2, v3, v4, v5, v6 in itertools.product(*ranges):    icky_thing(....)