2020-11-07
# 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
2. 自动协程，遇到I/O自动切换
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),
])
结果：
I'm doing my homework.
I have no time to watch TV.
Life is hard.
Stop thinking!
Keep doing my homework.
3. socket 协程实例：
服务器：
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)
客户端：
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()
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
