协程

通过生成器可以实现协程

协程

协程是一种并发运行机制，适用于I/O密集场景，有时候也称为微线程

协程就是利用生成器实现

协程应用举例

import os

# 装饰器，使生成器指向第一个yield
def coroutine(func):
    def start(*args, **kwargs):
        g = func(*args, **kwargs)
        g.__next__()
        return g
    return start

@coroutine
def find_files(target):
    while True:
        topdir = yield
        for path, dirname, filelist in os.walk(topdir):
            for name in filelist:
                if name.endswith(".py"):
                    print(name)
                    target.send(os.path.join(path, name))

@coroutine
def opener(target):
    while True:
        filename = yield
        with open(filename,"r") as f:
            for line in f.readlines():
                target.send(line)

@coroutine
def grepline():
    while True:
        line = yield
        print(line)


f_generate = find_files(opener(grepline()))
f_generate.send(".")