19-python-iterators

First, recursive iteration

Iteration: The next set of data is provided by the next method, which can only go backwards and not move forward.

In the list, the method a=l.__iter__ () makes the list conform to the iterator protocol, which can be converted to an iterative object using the A.next () method to fetch the list data

　　

Second, the principle of iterating the object with a for loop

　　

1 #-*-coding:utf-8-*-2 3s=[1,2,3,4,5,6,7]4Iter_s=s.__iter__()5  whileTrue:6     Try:7         Print(iter_s.__next__())8     exceptstopiteration:9         Print("Traversal End")Ten          Break

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19-python-iterators