异步IO

异步IO

协程

def odd():
    n=1
    while True:
        yield n
        n+=2
odd_num = odd()
count = 0
for o in odd_num:
    if count >=5: break
    print(o)
    count +=1

1
3
5
7
9

help(odd_num)

Help on generator object:

odd = class generator(object)
 |  Methods defined here:
 |  
 |  __del__(...)
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __iter__(self, /)
 |      Implement iter(self).
 |  
 |  __next__(self, /)
 |      Implement next(self).
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  close(...)
 |      close() -> raise GeneratorExit inside generator.
 |  
 |  send(...)
 |      send(arg) -> send 'arg' into generator,
 |      return next yielded value or raise StopIteration.
 |  
 |  throw(...)
 |      throw(typ[,val[,tb]]) -> raise exception in generator,
 |      return next yielded value or raise StopIteration.
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |  
 |  gi_code
 |  
 |  gi_frame
 |  
 |  gi_running
 |  
 |  gi_yieldfrom
 |      object being iterated by yield from, or None

def consumer():
    r=''
    while True:
        n = yield r
        print('[CONSUMER] Consuming %s' %n)
        r='200 OK'
def produce(c):
    #启动generator
    c.send(None)
    n = 0
    while n<5:
        n=n+1
        print('[PRODUCER] Producing %s...' % n)
        #将n传给cosumer()里的n,最后运行返回r
        r = c.send(n)
        print('[PRODUCER] Consumer return: %s' % r)
    c.close()

c = consumer()
produce(c)

[PRODUCER] Producing 1...
[CONSUMER] Consuming 1
[PRODUCER] Consumer return: 200 OK
[PRODUCER] Producing 2...
[CONSUMER] Consuming 2
[PRODUCER] Consumer return: 200 OK
[PRODUCER] Producing 3...
[CONSUMER] Consuming 3
[PRODUCER] Consumer return: 200 OK
[PRODUCER] Producing 4...
[CONSUMER] Consuming 4
[PRODUCER] Consumer return: 200 OK
[PRODUCER] Producing 5...
[CONSUMER] Consuming 5
[PRODUCER] Consumer return: 200 OK

asyncio

def writer():
    # 读取send传进的数据，并模拟写进套接字或文件
    while True:
        w = (yield)    # w接收send传进的数据
        print('>> ', w)
def writer_wrapper(coro):
    # TBD
    pass

w = writer()
wrap = writer_wrapper(w)
w.send(None)  # 生成器准备好接收数据
for i in range(4):
    w.send(i)

>>  0
>>  1
>>  2
>>  3

def writer():
    # 读取send传进的数据，并模拟写进套接字或文件
    while True:
        w = (yield)    # w接收send传进的数据
        print('>> ', w)
def writer_wrapper(coro2):
    #所有发送(send)到wrap的数都被直接发送到coro2
    yield from coro2

w = writer()
wrap = writer_wrapper(w)
wrap.send(None)
for i in range(4):
    wrap.send(i)

>>  0
>>  1
>>  2
>>  3

def writer_wrapper(coro1):
    coro1.send(None)  # 生成器准备好接收数据
    while True:
        try:
            x = (yield)  # x接收send传进的数据
            coro1.send(x)  # 然后将x在send给writer子生成器
        except StopIteration:    # 处理子生成器返回的异常
            pass