"Python learning" iterator iterator little exercise

Http://anandology.com/python-practice-book/iterators.html

Problem 1: Write an iterator class reverse_iter , which takes a list and iterates it from the reverse direction.::

>>>It=Reverse_iter([1,2,3,4])>>>it.  Next()4>>> it.  Next()3>>> it.  Next()2>>> it.  Next()1>>> it.  Next()Traceback (most recent): File ' <stdin> ', line 1, in <module>  Stopiteration                 

Wrote one, but realized, do not know whether the world's lowest efficiency.

Class Reverse_iter:
"" "DocString for ClassName" ""
def __init__ (Self,target):
self.current = 0
Self.target = target
Self.len = Len (target)
Print Self.len
Def next (self):
If Self.current < self.len:
Self.current+=1
return Self.target[self.len-self.current]
Else
Raise Stopiteration ()
def __iter__ (self):
return self

RI = Reverse_iter ([1,2,3,4])
Print Ri.next ()
Print Ri.next ()
Print Ri.next ()
Print Ri.next ()
Print Ri.next ()

"Python learning" iterator iterator little exercise