Basics python --- iterator

Iteration is one of the most powerful features of Python is a way to access the collection elements. 

Iterator can remember the object is a traverse position. 

Iterator object began a visit from the first element of the collection until all the elements are accessed session is over. Iterator can only move forward not backward. 

Iterator has two basic methods: iter () and next (). 

: Strings, a list of tuples or objects can be used to create iterators

 List = [1,2,3,4 ]
 IT = ITER (List)     # Create iterator object 
 Print (Next (IT))    # when the output of the iterator an element 
>>>. 1 Print (Next (IT))
 >>> 2 
iterator object may be used for a conventional traversing statement: 
List = [1,2,3,4 ] 
IT = ITER (List)     # Create iterator object for X in IT:
     Print (X, End = " " ) 
performing the above procedure, the output results are as follows: 1 2 3 4
 




 






May also be used next () function: 
Import sys          # incorporated sys module 
 
List = [1,2,3,4 ] 
IT = ITER (List)     # Create iterator object 
 
the while True:
     the try :
         Print (Next (IT))
     the except the StopIteration : 
        the sys.exit () 
performing the above procedure, the output results are as follows:

 . 1 
2 
. 3 
. 4