from collections import Iterable
isinstance({}, Iterable) --> True
isinstance((), Iterable) --> True
isinstance(100, Iterable) --> False

from collections import Iterator
isinstance({}, Iterator) --> False
isinstance((), Iterator) --> False
isinstance( (x for x in range(10)), Iterator) --> True

for x in [1,2,3,4,5]:
 pass

#先获取iterator对象
it = iter([1,2,3,4,5])
while True:
 try:
  #获取下一个值
  x = next(it);
 except StopIteration:
  # 遇到StopIteration就退出循环
  break