Greenlet

greenlet是一个用C实现的协程模块，相比与python自带的yield，它可以使你在任意函数之间随意切换，而不需把这个函数先声明为generator

from greenlet import greenletdef test1():    print(12)    gr2.switch()    print(34)    gr2.switch()def test2():    print(56) gr1.switch() print(78) gr1 = greenlet(test1) gr2 = greenlet(test2) gr1.switch()

 

 

Gevent 

Gevent 是一个第三方库，可以轻松通过gevent实现并发同步或异步编程，在gevent中用到的主要模式是Greenlet, 它是以C扩展模块形式接入Python的轻量级协程。 Greenlet全部运行在主程序操作系统进程的内部，但它们被协作式地调度。

import geventdef foo():    print('Running in foo')    gevent.sleep(2)    print('Running in foo2')def bar(): print('running bar') gevent.sleep(1) print('running bar2') def func3(): print("running func3 ") gevent.sleep(0) print("running func3 again ")

 

通过gevent实现单线程下的多socket并发

#server side import sysimport socketimport timeimport geventfrom gevent import socket,monkeymonkey.patch_all()def server(port): s = socket.socket() s.bind(('0.0.0.0', port)) s.listen(500) while True: cli, addr = s.accept() gevent.spawn(handle_request, cli) def handle_request(conn): try: while True: data = conn.recv(1024) print("recv:", data) conn.send(data) if not data: conn.shutdown(socket.SHUT_WR) except Exception as ex: print(ex) finally: conn.close() if __name__ == '__main__': server(8001)

#client side 　　import socketHOST = 'localhost'    # The remote hostPORT = 8001           # The same port as used by the servers = socket.socket(socket.AF_INET, socket.SOCK_STREAM)s.connect((HOST, PORT))while True:    msg = bytes(input(">>:"),encoding="utf8")    s.sendall(msg)    data = s.recv(1024) #print(data) print('Received', repr(data)) s.close()