


Recently there is a need to execute shell commands on the page.
The first one is os.system.
The code is as follows:
os.system('cat /proc/cpuinfo')
But I found that the page printed The command execution result is 0 or 1, which of course does not meet the requirements.
Try the second solution os.popen()
The code is as follows:
output = os.popen('cat /proc/cpuinfo') print output.read()
What is returned through os.popen() is the file read object, read it Take the read() operation to see the output of the execution. But the return value of program execution cannot be read)
Try the third solution commands.getstatusoutput(). You can get the return value and output in one method, which is very easy to use.
The code is as follows:
(status, output) = commands.getstatusoutput('cat /proc/cpuinfo') print status, output
An example given in the Python Document,
The code is as follows:
>>> import commands >>> commands.getstatusoutput('ls /bin/ls') (0, '/bin/ls') >>> commands.getstatusoutput('cat /bin/junk') (256, 'cat: /bin/junk: No such file or directory') >>> commands.getstatusoutput('/bin/junk') (256, 'sh: /bin/junk: not found') >>> commands.getoutput('ls /bin/ls') '/bin/ls' >>> commands.getstatus('/bin/ls') '-rwxr-xr-x 1 root 13352 Oct 14 1994 /bin/ls'
The above is the detailed content of Detailed explanation of three methods of executing shell commands in python. For more information, please follow other related articles on the PHP Chinese website!

Pythonlistsareimplementedasdynamicarrays,notlinkedlists.1)Theyarestoredincontiguousmemoryblocks,whichmayrequirereallocationwhenappendingitems,impactingperformance.2)Linkedlistswouldofferefficientinsertions/deletionsbutslowerindexedaccess,leadingPytho

Pythonoffersfourmainmethodstoremoveelementsfromalist:1)remove(value)removesthefirstoccurrenceofavalue,2)pop(index)removesandreturnsanelementataspecifiedindex,3)delstatementremoveselementsbyindexorslice,and4)clear()removesallitemsfromthelist.Eachmetho

Toresolvea"Permissiondenied"errorwhenrunningascript,followthesesteps:1)Checkandadjustthescript'spermissionsusingchmod xmyscript.shtomakeitexecutable.2)Ensurethescriptislocatedinadirectorywhereyouhavewritepermissions,suchasyourhomedirectory.

ArraysarecrucialinPythonimageprocessingastheyenableefficientmanipulationandanalysisofimagedata.1)ImagesareconvertedtoNumPyarrays,withgrayscaleimagesas2Darraysandcolorimagesas3Darrays.2)Arraysallowforvectorizedoperations,enablingfastadjustmentslikebri

Arraysaresignificantlyfasterthanlistsforoperationsbenefitingfromdirectmemoryaccessandfixed-sizestructures.1)Accessingelements:Arraysprovideconstant-timeaccessduetocontiguousmemorystorage.2)Iteration:Arraysleveragecachelocalityforfasteriteration.3)Mem

Arraysarebetterforelement-wiseoperationsduetofasteraccessandoptimizedimplementations.1)Arrayshavecontiguousmemoryfordirectaccess,enhancingperformance.2)Listsareflexiblebutslowerduetopotentialdynamicresizing.3)Forlargedatasets,arrays,especiallywithlib

Mathematical operations of the entire array in NumPy can be efficiently implemented through vectorized operations. 1) Use simple operators such as addition (arr 2) to perform operations on arrays. 2) NumPy uses the underlying C language library, which improves the computing speed. 3) You can perform complex operations such as multiplication, division, and exponents. 4) Pay attention to broadcast operations to ensure that the array shape is compatible. 5) Using NumPy functions such as np.sum() can significantly improve performance.

In Python, there are two main methods for inserting elements into a list: 1) Using the insert(index, value) method, you can insert elements at the specified index, but inserting at the beginning of a large list is inefficient; 2) Using the append(value) method, add elements at the end of the list, which is highly efficient. For large lists, it is recommended to use append() or consider using deque or NumPy arrays to optimize performance.


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

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 Linux new version
SublimeText3 Linux latest version

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

WebStorm Mac version
Useful JavaScript development tools

Atom editor mac version download
The most popular open source editor
