can't send non-None value to a just-started generator

 can't send non-None value to a just-started generator   第一次调用生成器不会复制

 1 def foo():
 2     print('OK')
 3 
 4     count=yield 1
 5     print(count)
 6 
 7     # print('OK2')
 8     # yield 2
 9 b=foo()
10 # print(next(b))
11 b.send(None) # 这句代码等同于   next(b)
12 # next(b)
13 # b.send(8)

结果：

"D:\Program Files (x86)\python36\python.exe" F:/python从入门到放弃/7.2/生成器2.py
OK

Process finished with exit code 0

出现报警现象是第一次调用就开始赋值：

 1 def foo():
 2     print('OK')
 3 
 4     count=yield 1
 5     print(count)
 6 
 7     # print('OK2')
 8     # yield 2
 9 b=foo()
10 # print(next(b))
11 # b.send(None) # 这句代码等同于   next(b)
12 # next(b)
13 b.send(8)

结果：

"D:\Program Files (x86)\python36\python.exe" F:/python从入门到放弃/7.2/生成器2.py
Traceback (most recent call last):
  File "F:/python从入门到放弃/7.2/生成器2.py", line 13, in <module>
    b.send(8)
TypeError: can't send non-None value to a just-started generator

Process finished with exit code 1

 

posted @ 2018-07-02 15:52  巨兽~墨菲特  阅读(442)  评论(0)  编辑  收藏  举报