Python 创建进程的三种方式-昊天SEO

# -*- coding: utf-8 -*-
"""
@Time: 2018/1/20
@Author: songhao
@微信公众号: zero<span class='wp_keywordlink_affiliate'><a href="https://www.168seo.cn/tag/python" title="View all posts in python" target="_blank">python</a></span>
@File: jincheng.py
"""
# 第一种方式：使用<span class='wp_keywordlink_affiliate'><a href="https://www.168seo.cn/tag/os" title="View all posts in os" target="_blank">os</a></span>模块中的fork方式实现多进程
import <span class='wp_keywordlink_affiliate'><a href="https://www.168seo.cn/tag/os" title="View all posts in os" target="_blank">os</a></span>
if __name__ == '__main__':
    print('current Process ({}) start ...'.format(<span class='wp_keywordlink_affiliate'><a href="https://www.168seo.cn/tag/os" title="View all posts in os" target="_blank">os</a></span>.getpid()))
    pid = os.fork()
    if pid < 0:
        print('error in fork')
    elif pid == 0:
        print('I am child process({0}) and my parent process is ({1})'.format(os.getpid(), os.getppid()))
    else:
        print('I({0}) created a chlid process ({1}).'.format(os.getpid(),pid))

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

# -*- coding: utf-8 -*-

"""

@Time: 2018/1/20

@Author: songhao

@微信公众号: zeropython

@File: jincheng.py

"""

# 第一种方式：使用os模块中的fork方式实现多进程

import os

if __name__ == '__main__':

print('current Process ({}) start ...'.format(os.getpid()))

pid = os.fork()

if pid < 0:

print('error in fork')

elif pid == 0:

print('I am child process({0}) and my parent process is ({1})'.format(os.getpid(), os.getppid()))

else:

print('I({0}) created a chlid process ({1}).'.format(os.getpid(),pid))

import os
from <span class='wp_keywordlink_affiliate'><a href="https://www.168seo.cn/tag/multiprocessing" title="View all posts in multiprocessing" target="_blank">multiprocessing</a></span> import Process
# 子进程要执行的代码
def run_proc(name):
    print('Child process {0} ({1}) Running...'.format(name, os.getpid()))
if __name__ == '__main__':
    print('Parent process %s.' % os.getpid())
    p_list=[]
    for i in range(5):
        p = Process(target=run_proc, args=(str(i),))
        p_list.append(p)
        print('Process will start.')
        p_list[i].start()
    for p in p_list:
        p.join()
    print('Process end.')

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

import os

from multiprocessing import Process

# 子进程要执行的代码

def run_proc(name):

print('Child process {0} ({1}) Running...'.format(name, os.getpid()))

if __name__ == '__main__':

print('Parent process %s.' % os.getpid())

p_list=[]

for i in range(5):

p = Process(target=run_proc, args=(str(i),))

p_list.append(p)

print('Process will start.')

p_list[i].start()

for p in p_list:

p.join()

print('Process end.')

from multiprocessing import Pool
import os, time, random

def run_task(name):
    print 'Task %s (pid = %s) is running...' % (name, os.getpid())
    time.sleep(random.random() * 3)
    print 'Task %s end.' % name

if __name__=='__main__':
    print 'Current process %s.' % os.getpid()
    p = Pool(processes=3)
    for i in range(5):
        p.apply_async(run_task, args=(i,))
    print 'Waiting for all subprocesses done...'
    p.close()
    p.join()
    print 'All subprocesses done.'

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

from multiprocessing import Pool

import os, time, random

def run_task(name):

print 'Task %s (pid = %s) is running...' % (name, os.getpid())

time.sleep(random.random() * 3)

print 'Task %s end.' % name

if __name__=='__main__':

print 'Current process %s.' % os.getpid()

p = Pool(processes=3)

for i in range(5):

p.apply_async(run_task, args=(i,))

print 'Waiting for all subprocesses done...'

p.close()

p.join()

print 'All subprocesses done.'

Queue进程间通信

from multiprocessing import Process, Queue
import os, time, random

# 写数据进程执行的代码:
def proc_write(q,urls):
    print('Process(%s) is writing...' % os.getpid())
    for url in urls:
        q.put(url)
        print('Put %s to queue...' % url)
        time.sleep(random.random())

# 读数据进程执行的代码:
def proc_read(q):
    print('Process(%s) is reading...' % os.getpid())
    while True:

        url = q.get(True)
        print('Get %s from queue.' % url)

if __name__=='__main__':
    # 父进程创建Queue，并传给各个子进程：
    q = Queue()
    proc_writer1 = Process(target=proc_write, args=(q,['url_1', 'url_2', 'url_3']))
    proc_writer2 = Process(target=proc_write, args=(q,['url_4','url_5','url_6']))
    proc_reader = Process(target=proc_read, args=(q,))
    # 启动子进程proc_writer，写入:
    proc_writer1.start()
    proc_writer2.start()
    # 启动子进程proc_reader，读取:
    proc_reader.start()
    # 等待proc_writer结束:
    proc_writer1.join()
    proc_writer2.join()
    # proc_reader进程里是死循环，无法等待其结束，只能强行终止:
    proc_reader.terminate()

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

Queue进程间通信

from multiprocessing import Process, Queue

import os, time, random

# 写数据进程执行的代码:

def proc_write(q,urls):

print('Process(%s) is writing...' % os.getpid())

for url in urls:

q.put(url)

print('Put %s to queue...' % url)

time.sleep(random.random())

# 读数据进程执行的代码:

def proc_read(q):

print('Process(%s) is reading...' % os.getpid())

while True:

url = q.get(True)

print('Get %s from queue.' % url)

if __name__=='__main__':

# 父进程创建Queue，并传给各个子进程：

q = Queue()

proc_writer1 = Process(target=proc_write, args=(q,['url_1', 'url_2', 'url_3']))

proc_writer2 = Process(target=proc_write, args=(q,['url_4','url_5','url_6']))

proc_reader = Process(target=proc_read, args=(q,))

# 启动子进程proc_writer，写入:

proc_writer1.start()

proc_writer2.start()

# 启动子进程proc_reader，读取:

proc_reader.start()

# 等待proc_writer结束:

proc_writer1.join()

proc_writer2.join()

# proc_reader进程里是死循环，无法等待其结束，只能强行终止:

proc_reader.terminate()

import multiprocessing
import random
import time,os

def proc_send(pipe,urls):
    for url in urls:
        print "Process(%s) send: %s" %(os.getpid(),url)
        pipe.send(url)
        time.sleep(random.random())

def proc_recv(pipe):
    while True:
        print "Process(%s) rev:%s" %(os.getpid(),pipe.recv())
        time.sleep(random.random())

1

2

3

4

5

6

7

8

9

10

11

12

13

14

import multiprocessing

import random

import time,os

def proc_send(pipe,urls):

for url in urls:

print "Process(%s) send: %s" %(os.getpid(),url)

pipe.send(url)

time.sleep(random.random())

def proc_recv(pipe):

while True:

print "Process(%s) rev:%s" %(os.getpid(),pipe.recv())

time.sleep(random.random())

Python 创建进程的三种方式

scrapy PipeLines 存储数据这一篇就够了

做爬虫你不会不知道Grequests库吧？（异步请求）

发表评论点击这里取消回复。

Python 创建进程的三种方式

scrapy PipeLines 存储数据这一篇就够了

做爬虫你不会不知道Grequests库吧？（异步请求）

猜你喜欢

百度输入法的词库 bdict 转 txt

Python 根据字符串调用本地函数

安卓 uiautomator设备测试 和选择器~Python详解

python描述符详解

Python3 getattr, getattrubute 区别和应用场景

python使用@property @x.setter @x.deleter

发表评论 点击这里取消回复。

关注我们的公众号

安卓 uiautomator设备测试和选择器~Python详解

发表评论点击这里取消回复。