Python iterator Zatan

Builder is an iterator, the iterator is not necessarily a generator

Iterables: list, tuple, dict, string, Iterable

What is an iterator?

Satisfy two conditions: 1, there iter method; 2, the next method

1 I=[1,2,3,4]
2 d=iter(I)
3 print(d)
4 print(next(d))
5 print(next(d))

 

for internal circulation three things

1, an iterative method calls iter object, returns an iterator object

2, continue to call the iterator object's next method

3, the processing exception StopIteration