search
HomeBackend DevelopmentPython TutorialSummary of two methods of executing shell in python

1. Use python’s built-in commands module to execute the shell

commands encapsulates Python’s os.popen(), uses the SHELL command string as its parameter, and returns the result data of the command and the status of the command execution. ;

This command is currently abandoned and replaced by subprocess;

# coding=utf-8
'''
Created on 2013年11月22日
  
@author: crazyant.net
'''
import commands
import pprint
  
def cmd_exe(cmd_String):
  print "will exe cmd,cmd:"+cmd_String
  return commands.getstatusoutput(cmd_String)
  
if __name__=="__main__":
  pprint.pprint(cmd_exe("ls -la"))

2. Use python’s latest subprocess module to execute the shell

Python has currently Abandoned os.system, os.spawn*, os.popen*, popen2.*, commands.* to execute commands in other languages, subprocesss is the recommended method;

subprocess allows you to create many subprocesses When creating a process, you can specify the subprocess and the input, output, and error output pipes of the subprocess. After execution, you can obtain the output results and execution status.

# coding=utf-8
'''
Created on 2013年11月22日
  
@author: crazyant.net
'''
import shlex
import datetime
import subprocess
import time
  
def execute_command(cmdstring, cwd=None, timeout=None, shell=False):
  """执行一个SHELL命令
      封装了subprocess的Popen方法, 支持超时判断,支持读取stdout和stderr
      参数:
    cwd: 运行命令时更改路径,如果被设定,子进程会直接先更改当前路径到cwd
    timeout: 超时时间,秒,支持小数,精度0.1秒
    shell: 是否通过shell运行
  Returns: return_code
  Raises: Exception: 执行超时
  """
  if shell:
    cmdstring_list = cmdstring
  else:
    cmdstring_list = shlex.split(cmdstring)
  if timeout:
    end_time = datetime.datetime.now() + datetime.timedelta(seconds=timeout)
   
  #没有指定标准输出和错误输出的管道,因此会打印到屏幕上;
  sub = subprocess.Popen(cmdstring_list, cwd=cwd, stdin=subprocess.PIPE,shell=shell,bufsize=4096)
   
  #subprocess.poll()方法:检查子进程是否结束了,如果结束了,设定并返回码,放在subprocess.returncode变量中
  while sub.poll() is None:
    time.sleep(0.1)
    if timeout:
      if end_time <= datetime.datetime.now():
        raise Exception("Timeout:%s"%cmdstring)
       
  return str(sub.returncode)
  
if __name__=="__main__":
  print execute_command("ls")

You can also specify stdin and stdout as a variable in Popen, so that you can directly receive the output variable value.

Summary

It is sometimes necessary to execute SHELL in python, such as using Python's thread mechanism to start different shell processes. Currently, subprocess is the officially recommended method of Python, and its supported functions It is also the most popular and is recommended for everyone to use.

Okay, that’s the entire content of this article. I hope the content of this article can be of some help to everyone’s study or work. If you have any questions, you can leave a message to communicate.

For more related articles summarizing the two methods of executing shell in python, please pay attention to the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
How to Use Python to Find the Zipf Distribution of a Text FileHow to Use Python to Find the Zipf Distribution of a Text FileMar 05, 2025 am 09:58 AM

This tutorial demonstrates how to use Python to process the statistical concept of Zipf's law and demonstrates the efficiency of Python's reading and sorting large text files when processing the law. You may be wondering what the term Zipf distribution means. To understand this term, we first need to define Zipf's law. Don't worry, I'll try to simplify the instructions. Zipf's Law Zipf's law simply means: in a large natural language corpus, the most frequently occurring words appear about twice as frequently as the second frequent words, three times as the third frequent words, four times as the fourth frequent words, and so on. Let's look at an example. If you look at the Brown corpus in American English, you will notice that the most frequent word is "th

Image Filtering in PythonImage Filtering in PythonMar 03, 2025 am 09:44 AM

Dealing with noisy images is a common problem, especially with mobile phone or low-resolution camera photos. This tutorial explores image filtering techniques in Python using OpenCV to tackle this issue. Image Filtering: A Powerful Tool Image filter

How Do I Use Beautiful Soup to Parse HTML?How Do I Use Beautiful Soup to Parse HTML?Mar 10, 2025 pm 06:54 PM

This article explains how to use Beautiful Soup, a Python library, to parse HTML. It details common methods like find(), find_all(), select(), and get_text() for data extraction, handling of diverse HTML structures and errors, and alternatives (Sel

How to Perform Deep Learning with TensorFlow or PyTorch?How to Perform Deep Learning with TensorFlow or PyTorch?Mar 10, 2025 pm 06:52 PM

This article compares TensorFlow and PyTorch for deep learning. It details the steps involved: data preparation, model building, training, evaluation, and deployment. Key differences between the frameworks, particularly regarding computational grap

Introduction to Parallel and Concurrent Programming in PythonIntroduction to Parallel and Concurrent Programming in PythonMar 03, 2025 am 10:32 AM

Python, a favorite for data science and processing, offers a rich ecosystem for high-performance computing. However, parallel programming in Python presents unique challenges. This tutorial explores these challenges, focusing on the Global Interprete

How to Implement Your Own Data Structure in PythonHow to Implement Your Own Data Structure in PythonMar 03, 2025 am 09:28 AM

This tutorial demonstrates creating a custom pipeline data structure in Python 3, leveraging classes and operator overloading for enhanced functionality. The pipeline's flexibility lies in its ability to apply a series of functions to a data set, ge

Serialization and Deserialization of Python Objects: Part 1Serialization and Deserialization of Python Objects: Part 1Mar 08, 2025 am 09:39 AM

Serialization and deserialization of Python objects are key aspects of any non-trivial program. If you save something to a Python file, you do object serialization and deserialization if you read the configuration file, or if you respond to an HTTP request. In a sense, serialization and deserialization are the most boring things in the world. Who cares about all these formats and protocols? You want to persist or stream some Python objects and retrieve them in full at a later time. This is a great way to see the world on a conceptual level. However, on a practical level, the serialization scheme, format or protocol you choose may determine the speed, security, freedom of maintenance status, and other aspects of the program

Mathematical Modules in Python: StatisticsMathematical Modules in Python: StatisticsMar 09, 2025 am 11:40 AM

Python's statistics module provides powerful data statistical analysis capabilities to help us quickly understand the overall characteristics of data, such as biostatistics and business analysis. Instead of looking at data points one by one, just look at statistics such as mean or variance to discover trends and features in the original data that may be ignored, and compare large datasets more easily and effectively. This tutorial will explain how to calculate the mean and measure the degree of dispersion of the dataset. Unless otherwise stated, all functions in this module support the calculation of the mean() function instead of simply summing the average. Floating point numbers can also be used. import random import statistics from fracti

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
1 months agoBy尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.

EditPlus Chinese cracked version

EditPlus Chinese cracked version

Small size, syntax highlighting, does not support code prompt function

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft