生成器 迭代器学习

def f1():
    print(11)
    yield 1

    print(22)
    yield 2

    print(33)
    yield 3
r = f1()
r1 = r.__next__()
print(r1)
r1 = r.__next__()
print(r1)
r1 = r.__next__()
print(r1)

11
1
22
2
33
3

range 生成原理
def f1(n):
   start = 0
   while True:
       if start > n:
           return
       else:
           yield start
           start += 1
r = f1(3)
r1 = r.__next__()
print(r1)
r1 = r.__next__()
print(r1)
r1 = r.__next__()
print(r1)

def f1(n):
   start = 0
   while True:
       if start > n:
           return
       else:
           yield start
           start += 1
for i in f1(3):
    print(i)

0
1
2
3