Python协程实战：手动切换与gevent自动调度详解

# pip install gevent
from greenlet import greenlet

def test():
  print('He ')
  gr2.switch() # 切换到test2
  print('a ')
  gr2.switch()

def test2():
  print('is ')
  gr1.switch()
  print('student.')

gr1 = greenlet(test)  # 创建一个协程
gr2 = greenlet(test2)
gr1.switch()  # 切换到gr1，也就是运行它

import gevent
from gevent import monkey; monkey.patch_all()  # 导入monkey，给所有支持的模块打上补丁，变成非阻塞模块，也就是使其能够进行协程操作
def test1(n):
  print("I'm doing my homework.")
  gevent.sleep(n)     # 模拟I/O操作，gevent自动切换
  print('Keep doing my homework.')

def test2(n):
  print("I have no time to watch TV.")
  gevent.sleep(n)
  print('Stop thinking!')

def test3():
  print("Life is hard.")

# 等待 greenlets 全部结束
gevent.joinall([
  gevent.spawn(test1,3), # 创建一个新的greeenlet对象，并规划它去执行 test1(3)
  gevent.spawn(test2,1),
  gevent.spawn(test3),
])

import socket
import gevent
from gevent import monkey
monkey.patch_all()  # 打补丁，让所有支持的模块变成非阻塞的方法

def server(ip,port):
  s = socket.socket()  # 生成socket对象
  s.bind((ip, port))  # 绑定ip和端口
  s.listen()      # 设置监听
  while True:
    cli, addr = s.accept()       # 等待连接
    gevent.spawn(handle_request, cli)  # 对每一个连接，使用协程的方法生成greenlet

def handle_request(conn):
  try:
    while True:
      data = conn.recv(1024)  # 接收数据
      print("recv:", data)
      new = 'Hello '+ data.decode().title()
      conn.send(new.encode('utf8'))      # 返回数据
      if not data:
        conn.shutdown(socket.SHUT_WR)
  except Exception as e:
    print(e)
  finally:
    conn.close()
if __name__ == '__main__':
  server('localhost',9999)

import socket
client = socket.socket()
client.connect(('localhost',9999))
while True:
  con = input('>>>:').strip()
  if len(con) ==0: continue
  client.send(con.encode('utf-8'))
  data = client.recv(1024)
  print(data.decode())
client.close()