gevent下的协程

安装gevent：

pychrm安装：
file -- settings -- Project: pythonProject -- Python Interpreter -- + -- 搜索gevent -- Install Package

#Greenlet

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

from greenlet import greenlet

def test1():
    print('12')
    gr2.switch()
    print('34')
    gr2.switch()

def test2():
    print('56')
    gr1.switch()
    print('78')

gr1 = greenlet(test1)
print(gr1)  ##<greenlet.greenlet object at 0x000000000212DB90>
# gr2 = greenlet(test2)
# gr1.switch()    #用来完成greenlet对象切换

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py
<greenlet.greenlet object at 0x7f7379ae33b0 (otid=0x7f7379ba4280) pending>

Process finished with exit code 0

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

from greenlet import greenlet

def test1():
    print('12')
    gr2.switch()
    print('34')
    gr2.switch()

def test2():
    print('56')
    gr1.switch()
    print('78')

gr1 = greenlet(test1)
# print(gr1)  ##<greenlet.greenlet object at 0x000000000212DB90>
gr2 = greenlet(test2)
# gr1.switch()    #用来完成greenlet对象切换

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py

Process finished with exit code 0

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

from greenlet import greenlet

def test1():
    print('12')
    gr2.switch()
    print('34')
    gr2.switch()

def test2():
    print('56')
    gr1.switch()
    print('78')

gr1 = greenlet(test1)
# print(gr1)  ##<greenlet.greenlet object at 0x000000000212DB90>
gr2 = greenlet(test2)
gr1.switch()    #用来完成greenlet对象切换

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py
12
56
34
78

Process finished with exit code 0

#Gevent

#Gevent是一个第三方库，可以轻松通过gevent实行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，但它们协作式地调度。

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

import gevent
import time

def foo():
    print('Running in foo',time.ctime())
    gevent.sleep(1) #模拟i/o阻塞,不能使用time.sleep是cpu切换，现在是一个线程切换。
    print('Explicit context switch to foo again',time.ctime())

def bar():
    print('Explicit context to bar',time.ctime())
    gevent.sleep(2)
    print('Implicit context switch back to bar',time.ctime())

gevent.joinall([
    gevent.spawn(foo),
    gevent.spawn(bar),
])

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py
Running in foo Thu May 27 22:01:42 2021
Explicit context to bar Thu May 27 22:01:42 2021
Explicit context switch to foo again Thu May 27 22:01:43 2021
Implicit context switch back to bar Thu May 27 22:01:44 2021

Process finished with exit code 0

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

import gevent
import time

def foo():
    print('Running in foo',time.ctime())
    time.sleep(1) #模拟i/o阻塞,不能使用time.sleep是cpu切换，现在是一个线程切换。
    print('Explicit context switch to foo again',time.ctime())

def bar():
    print('Explicit context to bar',time.ctime())
    time.sleep(2)
    print('Implicit context switch back to bar',time.ctime())

gevent.joinall([
    gevent.spawn(foo),
    gevent.spawn(bar),
])

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py
Running in foo Thu May 27 22:04:37 2021
Explicit context switch to foo again Thu May 27 22:04:38 2021
Explicit context to bar Thu May 27 22:04:38 2021
Implicit context switch back to bar Thu May 27 22:04:40 2021

Process finished with exit code 0

#爬虫

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

from gevent import monkey;

#monkey.patch_all()
import gevent
from urllib.request import urlopen

def f(url):
    print('GET: %s' % url)
    resp = urlopen(url)
    data = resp.read()
    with open('xiaohua.html','wb') as f:
        f.write(data)
    print('%d bytes received from %s.' % (len(data),url))

f('http://www.xiaohuar.com')

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py
GET: http://www.xiaohuar.com
24338 bytes received from http://www.xiaohuar.com.

Process finished with exit code 0

查看xiaohua.html文件

smoke@smoke-GS70-2PC-Stealth:~$ cat 文档/DocumentFile/PycharmProjects/pythonProject/join/xiaohua.html | more
<!doctype html>
<html lang="zh-CN">

        <head>
                <meta charset="utf-8">
                <meta http-equiv="X-UA-Compatible" content="IE=edge">
                <meta name="viewport" content="width=device-width, initial-scale=1">
<title>中国大学生校花网-清纯校花美女图片大全</title>

点击谷歌浏览器按钮可以打开爬下来的页面

通过IO组在时会自动切换任务

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

from gevent import monkey;

#monkey.patch_all()
import gevent
from urllib.request import urlopen
import time

def f(url):
    print('GET: %s' % url)
    resp = urlopen(url)
    data = resp.read()

    print('%d bytes received from %s.' % (len(data),url))

l=['https://www.taobao.com/','https://www.baidu.com/','https://www.qq.com/']

start=time.time()
for url in l:
    f(url)

print(time.time()-start)

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py
GET: https://www.taobao.com/
110268 bytes received from https://www.taobao.com/.
GET: https://www.baidu.com/
227 bytes received from https://www.baidu.com/.
GET: https://www.qq.com/
22125 bytes received from https://www.qq.com/.
5.599690675735474

Process finished with exit code 0

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

from gevent import monkey;

#monkey.patch_all()
import gevent
from urllib.request import urlopen
import time

def f(url):
    print('GET: %s' % url)
    resp = urlopen(url)
    data = resp.read()

    print('%d bytes received from %s.' % (len(data),url))

start=time.time()

gevent.joinall([
    gevent.spawn(f,'https://www.taobao.com/'),
    gevent.spawn(f,'https://www.baidu.com/'),
    gevent.spawn(f,'https://www.qq.com/')
])

print(time.time()-start)

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py
GET: https://www.taobao.com/
110200 bytes received from https://www.taobao.com/.
GET: https://www.baidu.com/
227 bytes received from https://www.baidu.com/.
GET: https://www.qq.com/
22125 bytes received from https://www.qq.com/.
0.5885026454925537

Process finished with exit code 0

#!/usr/bin/env python3.8
# -*- coding: UTF-8 -*-
# __author: smoke
# file: gevent_xiecheng
# time: 2021/05/27

from gevent import monkey;
monkey.patch_all()  #补丁，最大程度监听i/o阻塞
import gevent
from urllib.request import urlopen
import time

def f(url):
    print('GET: %s' % url)
    resp = urlopen(url)
    data = resp.read()

    print('%d bytes received from %s.' % (len(data),url))

start = time.time()

gevent.joinall([
    gevent.spawn(f,'https://www.taobao.com/'),
    gevent.spawn(f,'https://www.baidu.com/'),
    gevent.spawn(f,'https://www.qq.com/')
])

print(time.time()-start)

/home/smoke/文档/DocumentFile/PycharmProjects/选课系统Demo/Jaime/venv/bin/python /home/smoke/文档/DocumentFile/PycharmProjects/pythonProject/join/gevent_xiecheng.py
GET: https://www.taobao.com/
GET: https://www.baidu.com/
GET: https://www.qq.com/
227 bytes received from https://www.baidu.com/.
110200 bytes received from https://www.taobao.com/.
22125 bytes received from https://www.qq.com/.
0.22603464126586914

Process finished with exit code 0

发表于 2021-05-27 22:16 深秋、阅读(87) 评论(0) 收藏举报

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