Python--30 iterators

Iterators

A dictionary of iterator sequences (list tuple strings) that we typically contact

You typically use the For statement to iterate

Python offers two bif

ITER ()

__ITER__ ()

Next ()

__next__ ()

 for inch ' Junjie ' :...      Print (i) ... Junjie

 for inch Links:      ... Print (StackOverflow,%s, '%s' )

>>> string ='Junjie'>>> it =iter (String)>>>Next (IT)'J'>>>Next (IT)'u'>>>Next (IT)'N'>>>Next (IT)'J'>>>Next (IT)'I'>>>Next (IT)'e'>>>Next (IT) Traceback (most recent): File"<stdin>", Line 1,inch<module>stopiteration

 >>> string =  " junjie   " >>> it = iter (string)  >>> while   True: ...  try  : ... each  = next (it) ...  except   stopiteration: ...  break   ...  print   

 for inch string:      ... Print (each) ... Junjie

Magic method

>>>classFibs: ...def __init__(self): ... self.a=0 ... self.b= 1...     def __iter__(self): ...returnSelf ...def __next__(self): ... self.a,self.b= self.b,self.a+self.b ...returnself.a ...>>> foreachinchfibs: ...ifEach < 20:...             Print(each) ...Else:...              Break... 11235813

>>>classFibs: ...def __init__(self,n=10): ... self.a=0 ... self.b= 1. .. self.n=n . ...def __iter__(self): ...returnSelf ...def __next__(self): ... self.a,self.b= SELF.B,SELF.A +self.b ...ifSELF.A >SELF.N: ...Raisestopiteration ...returnself.a ...>>> fibs =Fibs ()>>> foreachinchfibs: ...Print(each) ...112358

Python--30 iterators