search
HomeBackend DevelopmentPython Tutorialpython中sys.argv参数用法实例分析

本文实例讲述了python中sys.argv参数用法。分享给大家供大家参考。具体分析如下:

在学python的过程中,一直弄不明白sys.argv[]的意思,虽知道是表示命令行参数,但还是有些稀里糊涂的感觉。

今天又好好学习了一把,总算是大彻大悟了。

Sys.argv[]是用来获取命令行参数的,sys.argv[0]表示代码本身文件路径,所以参数从1开始,以下两个例子说明:

1、使用sys.argv[]的一简单实例

import sys,os
os.system(sys.argv[1])

这个例子os.system接收命令行参数,运行参数指令,保存为sample1.py,命令行带参数运行sample1.py notepad,将打开记事本程序。

2、这个例子是简明python教程上的,明白它之后你就明白sys.argv[]了。

import sys
def readfile(filename): #从文件中读出文件内容
'''Print a file to the standard output.'''
f = file(filename)
while True:
line = f.readline()
if len(line) == 0:
break
print line, # notice comma 分别输出每行内容
f.close()
# Script starts from here
if len(sys.argv) < 2:
print 'No action specified.'
sys.exit()
if sys.argv[1].startswith('--'):
option = sys.argv[1][2:]
# fetch sys.argv[1] but without the first two characters
if option == 'version': #当命令行参数为-- version,显示版本号
print 'Version 1.2'
elif option == 'help': #当命令行参数为--help时,显示相关帮助内容
print '''"
This program prints files to the standard output.
Any number of files can be specified.
Options include:
--version : Prints the version number
--help  : Display this help'''
else:
print 'Unknown option.'
sys.exit()
else:
for filename in sys.argv[1:]: #当参数为文件名时,传入readfile,读出其内容
readfile(filename)

保存程序为sample.py.我们验证一下:

命令行带参数运行:sample.py –version 输出结果为:version 1.2

命令行带参数运行:sample.py –help 输出结果为:This program prints files……

在与sample.py同一目录下,新建a.txt的记事本文件,内容为:test argv;命令行带参数运行:sample.py a.txt,输出结果为a.txt文件内容:test argv,这里也可多带几个参数,程序会先后输出参数文件内容。

希望本文所述对大家的Python程序设计有所帮助。

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
What data types can be stored in a Python array?What data types can be stored in a Python array?Apr 27, 2025 am 12:11 AM

Pythonlistscanstoreanydatatype,arraymodulearraysstoreonetype,andNumPyarraysarefornumericalcomputations.1)Listsareversatilebutlessmemory-efficient.2)Arraymodulearraysarememory-efficientforhomogeneousdata.3)NumPyarraysareoptimizedforperformanceinscient

What happens if you try to store a value of the wrong data type in a Python array?What happens if you try to store a value of the wrong data type in a Python array?Apr 27, 2025 am 12:10 AM

WhenyouattempttostoreavalueofthewrongdatatypeinaPythonarray,you'llencounteraTypeError.Thisisduetothearraymodule'sstricttypeenforcement,whichrequiresallelementstobeofthesametypeasspecifiedbythetypecode.Forperformancereasons,arraysaremoreefficientthanl

Which is part of the Python standard library: lists or arrays?Which is part of the Python standard library: lists or arrays?Apr 27, 2025 am 12:03 AM

Pythonlistsarepartofthestandardlibrary,whilearraysarenot.Listsarebuilt-in,versatile,andusedforstoringcollections,whereasarraysareprovidedbythearraymoduleandlesscommonlyusedduetolimitedfunctionality.

What should you check if the script executes with the wrong Python version?What should you check if the script executes with the wrong Python version?Apr 27, 2025 am 12:01 AM

ThescriptisrunningwiththewrongPythonversionduetoincorrectdefaultinterpretersettings.Tofixthis:1)CheckthedefaultPythonversionusingpython--versionorpython3--version.2)Usevirtualenvironmentsbycreatingonewithpython3.9-mvenvmyenv,activatingit,andverifying

What are some common operations that can be performed on Python arrays?What are some common operations that can be performed on Python arrays?Apr 26, 2025 am 12:22 AM

Pythonarrayssupportvariousoperations:1)Slicingextractssubsets,2)Appending/Extendingaddselements,3)Insertingplaceselementsatspecificpositions,4)Removingdeleteselements,5)Sorting/Reversingchangesorder,and6)Listcomprehensionscreatenewlistsbasedonexistin

In what types of applications are NumPy arrays commonly used?In what types of applications are NumPy arrays commonly used?Apr 26, 2025 am 12:13 AM

NumPyarraysareessentialforapplicationsrequiringefficientnumericalcomputationsanddatamanipulation.Theyarecrucialindatascience,machinelearning,physics,engineering,andfinanceduetotheirabilitytohandlelarge-scaledataefficiently.Forexample,infinancialanaly

When would you choose to use an array over a list in Python?When would you choose to use an array over a list in Python?Apr 26, 2025 am 12:12 AM

Useanarray.arrayoveralistinPythonwhendealingwithhomogeneousdata,performance-criticalcode,orinterfacingwithCcode.1)HomogeneousData:Arrayssavememorywithtypedelements.2)Performance-CriticalCode:Arraysofferbetterperformancefornumericaloperations.3)Interf

Are all list operations supported by arrays, and vice versa? Why or why not?Are all list operations supported by arrays, and vice versa? Why or why not?Apr 26, 2025 am 12:05 AM

No,notalllistoperationsaresupportedbyarrays,andviceversa.1)Arraysdonotsupportdynamicoperationslikeappendorinsertwithoutresizing,whichimpactsperformance.2)Listsdonotguaranteeconstanttimecomplexityfordirectaccesslikearraysdo.

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

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

MinGW - Minimalist GNU for Windows

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.

EditPlus Chinese cracked version

EditPlus Chinese cracked version

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

DVWA

DVWA

Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment