python 自定义迭代器

def frange(start, stop, increment):
 x = start
 while x < stop:
 yield x
 x += increment
   for n in frange(0, 4, 0.5):
 ...     print(n)
 ...
 0
 0.5
 1.0
 1.5
 2.0
 2.5
 3.0
 3.5
 list(frange(0, 1, 0.125))
 [0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875]