Python多进程并发(multiprocessing)用法实例详解
本文实例讲述了Python多进程并发(multiprocessing)用法。分享给大家供大家参考。具体分析如下：
由于Python设计的限制(我说的是咱们常用的CPython)。最多只能用满1个CPU核心。
Python提供了非常好用的多进程包multiprocessing，你只需要定义一个函数，Python会替你完成其他所有事情。借助这个包，可以轻松完成从单进程到并发执行的转换。
1、新建单一进程
如果我们新建少量进程，可以如下：
import multiprocessing
import time
def func(msg):
for i in xrange(3):
print msg
time.sleep(1)
if __name__ == "__main__":
p = multiprocessing.Process(target=func, args=("hello", ))
p.start()
p.join()
print "Sub-process done."2、使用进程池
是的，你没有看错，不是线程池。它可以让你跑满多核CPU，而且使用方法非常简单。
注意要用apply_async，如果落下async，就变成阻塞版本了。
processes=4是最多并发进程数量。
import multiprocessing
import time
def func(msg):
for i in xrange(3):
print msg
time.sleep(1)
if __name__ == "__main__":
pool = multiprocessing.Pool(processes=4)
for i in xrange(10):
msg = "hello %d" %(i)
pool.apply_async(func, (msg, ))
pool.close()
pool.join()
print "Sub-process(es) done."3、使用Pool，并需要关注结果
更多的时候，我们不仅需要多进程执行，还需要关注每个进程的执行结果，如下：
import multiprocessing
import time
def func(msg):
for i in xrange(3):
print msg
time.sleep(1)
return "done " + msg
if __name__ == "__main__":
pool = multiprocessing.Pool(processes=4)
result = []
for i in xrange(10):
msg = "hello %d" %(i)
result.append(pool.apply_async(func, (msg, )))
pool.close()
pool.join()
for res in result:
print res.get()
print "Sub-process(es) done."希望本文所述对大家的Python程序设计有所帮助。
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1670
14
1428
52
1329
25
1274
29
1256
24
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
Choosing Between PHP and Python: A Guide
Apr 18, 2025 am 12:24 AM
PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.
How to run sublime code python
Apr 16, 2025 am 08:48 AM
To run Python code in Sublime Text, you need to install the Python plug-in first, then create a .py file and write the code, and finally press Ctrl B to run the code, and the output will be displayed in the console.
PHP and Python: A Deep Dive into Their History
Apr 18, 2025 am 12:25 AM
PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.
Python vs. JavaScript: The Learning Curve and Ease of Use
Apr 16, 2025 am 12:12 AM
Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
Golang vs. Python: Performance and Scalability
Apr 19, 2025 am 12:18 AM
Golang is better than Python in terms of performance and scalability. 1) Golang's compilation-type characteristics and efficient concurrency model make it perform well in high concurrency scenarios. 2) Python, as an interpreted language, executes slowly, but can optimize performance through tools such as Cython.
Where to write code in vscode
Apr 15, 2025 pm 09:54 PM
Writing code in Visual Studio Code (VSCode) is simple and easy to use. Just install VSCode, create a project, select a language, create a file, write code, save and run it. The advantages of VSCode include cross-platform, free and open source, powerful features, rich extensions, and lightweight and fast.
How to run python with notepad
Apr 16, 2025 pm 07:33 PM
Running Python code in Notepad requires the Python executable and NppExec plug-in to be installed. After installing Python and adding PATH to it, configure the command "python" and the parameter "{CURRENT_DIRECTORY}{FILE_NAME}" in the NppExec plug-in to run Python code in Notepad through the shortcut key "F6".
