python多进程与多线程一

2018年5月7日22:33:43 发表评论 1,313 views

1、启动一个进程
2、启动多个进程

mutilprocessing

1、启动一个进程

#encoding:utf8

import os
import time
from multiprocessing import Process

__author__ = 'quanjie'

def run_proc(name):
    time.sleep(3)
    print('Child process %s(%s) Running ...'%(name,os.getpid()))

if __name__ == '__main__':
    print('Parent process %s.'%os.getpid())
    p = Process(target=run_proc,args=("multiprocessing",))#************
    print('Process will start.')
    p.start()
    p.join()#****************
    print('Process end.')

#encoding:utf8

import os

import time

from multiprocessing import Process

__author__ = 'quanjie'

def run_proc(name):

time.sleep(3)

print('Child process %s(%s) Running ...'%(name,os.getpid()))

if __name__ == '__main__':

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

p = Process(target=run_proc,args=("multiprocessing",))#************

print('Process will start.')

p.start()

p.join()#****************

print('Process end.')

a、Process(函数名，参数),参数以元组的形式给出。

b、p.join()等待子进程运行完了，父进程才继续向下运行。

2、启动多个进程

(1)、不使用pool

def run_proc(name):
    time.sleep(3)
    print('Child process %s(%s) Running ...'%(name,os.getpid()))

if __name__ == '__main__':

    print('Parent process %s.'%os.getpid())
    for i in range(5):
        p = Process(target=run_proc,args=(str(i),))
        print('Process will start.')
        p.start()
    p.join()
    print('Process end.')

def run_proc(name):

time.sleep(3)

print('Child process %s(%s) Running ...'%(name,os.getpid()))

if __name__ == '__main__':

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

for i in range(5):

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

print('Process will start.')

p.start()

p.join()

print('Process end.')

结果：

Parent process 6428.
Process will start.
Process will start.
Process will start.
Process will start.
Process will start.
Child process 0(6429) Running ...
Child process 1(6430) Running ...
Child process 2(6431) Running ...
Child process 3(6432) Running ...
Child process 4(6433) Running ...
Process end.

Parent process 6428.

Process will start.

Child process 0(6429) Running ...

Child process 1(6430) Running ...

Child process 2(6431) Running ...

Child process 3(6432) Running ...

Child process 4(6433) Running ...

Process end.

(2)、使用pool来管理和启动线程

if __name__ == '__main__':

    print('Parent process %s.'%os.getpid())
    p = Pool(processes=3)
    for i in range(5):
        p.apply_async(run_proc,args=(str(i),))

    p.close()
    p.join()
    print('All subprocesses done.')

if __name__ == '__main__':

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

p = Pool(processes=3)

for i in range(5):

p.apply_async(run_proc,args=(str(i),))

p.close()

p.join()

print('All subprocesses done.')

结果：

Parent process 6549.
Child process 0(6550) Running ...
Child process 1(6551) Running ...
Child process 2(6552) Running ...
Child process 3(6550) Running ...
Child process 4(6551) Running ...
All subprocesses done.

Parent process 6549.

Child process 0(6550) Running ...

Child process 1(6551) Running ...

Child process 2(6552) Running ...

Child process 3(6550) Running ...

Child process 4(6551) Running ...

All subprocesses done.

threading

(1)、创建一个线程(函数)

#encoding:utf8
__author__ = 'quanjie'
import random
import threading
import time

def thread_run(urls):
    print('Current %s is running...' % threading.current_thread().getName())
    for url in urls:
        print('%s ------>> %s'%(threading.current_thread().name,url))
        time.sleep(random.random())
    print('%s ended'%threading.current_thread().name)

if __name__ == '__main__':
    print('%s is running......'% threading.current_thread().name)
    print(threading.current_thread().getName())
    print()
    t1 = threading.Thread(target=thread_run,name='Thread_1',args=(['url_1','url_2','url_3'],))
    t2 = threading.Thread(target=thread_run,name='Thread_2',args=(['url_4','url_5','url_6'],))

    t1.start()
    t2.start()
    t1.join()
    t2.join()
    print('%s ended.'%threading.current_thread().name)

#encoding:utf8

__author__ = 'quanjie'

import random

import threading

import time

def thread_run(urls):

print('Current %s is running...' % threading.current_thread().getName())

for url in urls:

print('%s ------>> %s'%(threading.current_thread().name,url))

time.sleep(random.random())

print('%s ended'%threading.current_thread().name)

if __name__ == '__main__':

print('%s is running......'% threading.current_thread().name)

print(threading.current_thread().getName())

print()

t1 = threading.Thread(target=thread_run,name='Thread_1',args=(['url_1','url_2','url_3'],))

t2 = threading.Thread(target=thread_run,name='Thread_2',args=(['url_4','url_5','url_6'],))

t1.start()

t2.start()

t1.join()

t2.join()

print('%s ended.'%threading.current_thread().name)

结果：

MainThread is running......
MainThread

Current Thread_1 is running...
Thread_1 ------>> url_1
Current Thread_2 is running...
Thread_2 ------>> url_4
Thread_2 ------>> url_5
Thread_1 ------>> url_2
Thread_2 ------>> url_6
Thread_2 ended
Thread_1 ------>> url_3
Thread_1 ended
MainThread ended.

MainThread is running......

MainThread

Current Thread_1 is running...

Thread_1 ------>> url_1

Current Thread_2 is running...

Thread_2 ------>> url_4

Thread_2 ------>> url_5

Thread_1 ------>> url_2

Thread_2 ------>> url_6

Thread_2 ended

Thread_1 ------>> url_3

Thread_1 ended

MainThread ended.

a、threading.current_thread().getName()和threading.current_thread().name同样的作用。

b、t.join()的作用是等待当前线程执行完了，才往下执行。

(2)、创建一个线程(类)

class myThread(threading.Thread):
    def __init__(self,name,urls):
        threading.Thread.__init__(self,name=name)#********参数self，不能少
        self.urls = urls
    def run(self):
        print('Current %s is running...' % threading.current_thread().getName())
        for url in self.urls:
            print('%s ------>> %s'%(threading.current_thread().name,url))
            time.sleep(random.random())
        print('%s ended'%threading.current_thread().name)
if __name__ == '__main__':
    print('%s is running......'% threading.current_thread().name)
    print(threading.current_thread().getName())
    print()
    t1 = myThread(name='Thread_1',urls =['url_1','url_2','url_3'])
    t2 = myThread('Thread_2',['url_4','url_5','url_6'])

    t1.start()
    t2.start()
    print('%s ended.'%threading.current_thread().name)

class myThread(threading.Thread):

def __init__(self,name,urls):

threading.Thread.__init__(self,name=name)#********参数self，不能少

self.urls = urls

def run(self):

print('Current %s is running...' % threading.current_thread().getName())

for url in self.urls:

print('%s ------>> %s'%(threading.current_thread().name,url))

time.sleep(random.random())

print('%s ended'%threading.current_thread().name)

if __name__ == '__main__':

print('%s is running......'% threading.current_thread().name)

print(threading.current_thread().getName())

print()

t1 = myThread(name='Thread_1',urls =['url_1','url_2','url_3'])

t2 = myThread('Thread_2',['url_4','url_5','url_6'])

t1.start()

t2.start()

print('%s ended.'%threading.current_thread().name)

结果(这是没有join的结果)：

MainThread is running......
MainThread

Current Thread_1 is running...
Thread_1 ------>> url_1
Current Thread_2 is running...
MainThread ended.
Thread_2 ------>> url_4
Thread_2 ------>> url_5
Thread_1 ------>> url_2
Thread_2 ------>> url_6
Thread_2 ended
Thread_1 ------>> url_3
Thread_1 ended