实例讲解Python 迭代器与生成器

> list=[1,2,3,4]
> it = iter(list) # 创建迭代器对象
> print (next(it)) # 输出迭代器的下一个元素
1
> print (next(it))
2
>

#!/usr/bin/python3
 
list=[1,2,3,4]
it = iter(list) # 创建迭代器对象
for x in it:
 print (x, end=" ")

#!/usr/bin/python3
 
import sys   # 引入 sys 模块
 
list=[1,2,3,4]
it = iter(list) # 创建迭代器对象
 
while True:
 try:
  print (next(it))
 except StopIteration:
  sys.exit()

class MyNumbers:
 def __iter__(self):
 self.a = 1
 return self
 
 def __next__(self):
 x = self.a
 self.a += 1
 return x
 
myclass = MyNumbers()
myiter = iter(myclass)
 
print(next(myiter))
print(next(myiter))
print(next(myiter))
print(next(myiter))
print(next(myiter))

class MyNumbers:
 def __iter__(self):
 self.a = 1
 return self
 
 def __next__(self):
 if self.a <= 20:
  x = self.a
  self.a += 1
  return x
 else:
  raise StopIteration
 
myclass = MyNumbers()
myiter = iter(myclass)
 
for x in myiter:
 print(x)

#!/usr/bin/python3
 
import sys
 
def fibonacci(n): # 生成器函数 - 斐波那契
 a, b, counter = 0, 1, 0
 while True:
  if (counter > n): 
   return
  yield a
  a, b = b, a + b
  counter += 1
f = fibonacci(10) # f 是一个迭代器，由生成器返回生成
 
while True:
 try:
  print (next(f), end=" ")
 except StopIteration:
  sys.exit()