8.python Object-oriented (implementation of an iterator protocol via __iter__,__next__) with Fibonacci sequence implementations

In front of the iterator and generator principle, it has been said that the __iter__ method and the role of the __next__ method, here do not repeat the description.

In this complement an example of implementing an iterator protocol.

Example 1: (The iterator generates an infinite value before the exception is thrown stopiteration)

Class C1:

def __init__ (Self,start):

Self.start = Start

def __iter__ (self):

return self

Def next (self):

Self.start + = 1

Return Self.start

O1 = C1 (10)

For I in O1:

Print I

Example 2: (After throwing an stopiteration exception)

Class C1:

def __init__ (self,start,stop):

Self.start = Start

Self.stop = Stop

def __iter__ (self):

return self

Def next (self):

If Self.start >= self.stop:

Raise Stopiteration

n = Self.start

Self.start + = 1

return n

O1 = C1 (1,10)

For I in O1:

Print I

Output:

1

2

3

4

5

6

7

8

9

Fibonacci Sequence:

Class Fib:

def __init__ (self):

Self._a=0

Self._b=1

def __iter__ (self):

return self

def __next__ (self):

Self._a,self._b=self._b,self._a + self._b

Return self._a

F1=FIB ()

This article is from the "Rebirth" blog, make sure to keep this source http://suhaozhi.blog.51cto.com/7272298/1918569

8.python Object-oriented (implementation of an iterator protocol via __iter__,__next__) with Fibonacci sequence implementations