python中迭代器（iterator）用法实例分析

#---------------------------------------
#      Name: iterators.py
#     Author: Kevin Harris
# Last Modified: 03/11/04
# Description: This Python script demonstrates how to use iterators.
#---------------------------------------
myTuple = (1, 2, 3, 4)
myIterator = iter( myTuple )
print( next( myIterator ) )
print( next( myIterator ) )
print( next( myIterator ) )
print( next( myIterator ) )
# Becareful, one more call to next() 
# and this script will throw an exception!
#print myIterator.next() 
print( " " )
#---------------------------------------
# If you have no idea how many items 
# can be safely accesd via the iterator,
# use a try/except block to keep your script from crashing.
myTuple2 = ( "one", "two", "three", "four" )
myIterator2 = iter( myTuple2 )
while 1:
  try:
    print( next( myIterator2 ) )
  except StopIteration:
    print( "Exception caught! Iterator must be empty!" )
    break
input( '\n\nPress Enter to exit...' )