[Python] sys.argv命令行参数传入

Posted 2020-10-29 CSnow码工养成中

书上一道题需要实现功能"根据账号查询密码, 复制密码到剪贴板". 账号和密码储存在代码字典中. 

问题描述:

作为Python新手从代码(如下)看只知道:

1. sys.argv初始包含一行文件路径.

2. 需要将待查询的账号传入sys.argv.

怎么操作呢?

#! python3
#pw.py - An inssecure password locker program.
#Run this program in  CMD, parameter (account) load after filename. Like: pw.py email

PASSWORDS={‘email‘:‘F7minlBDDuvJJux‘, ‘blog‘:‘VmALvWyKAxiVH5‘,‘luggage‘:‘12345‘}

import sys,pyperclip
if len(sys.argv)<2:
              print(‘Usage: python pw.py [account] - copy account password‘)
              sys.exit()

account=sys.argv[1] # first command line arg is the account name

if account in PASSWORDS:
              pyperclip.copy(PASSWORDS[account])
              print(‘Password for ‘+account+‘ copied to clipboard.‘)
else:
              print(‘There is no account named ‘+account)
              

 

解决思路:

命令行参数, 通过命令行来操作了.

在CMD中cd到pw.py的目录下, 敲如命令时将参数置于文件名之后. 如下图, 搞定了.

D:\DIV\PyScripts>pw.py blog
Password for blog copied to clipboard.

D:\DIV\PyScripts>pw.py luggage
Password for luggage copied to clipboard.

D:\DIV\PyScripts>pw.py email
Password for email copied to clipboard.

D:\DIV\PyScripts>

 

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备注:

sys.argv用import导入, 初始值是运行文件所在路径+文件名, 传入账号之后账号的值被添加到了sys.argv中, 如下:

[‘D:\\DIV\\PyScripts\\pw.py‘, ‘email‘]

程序运行完成之后再试图打印sys.argv就不行了, 传入的参数被释放.

 

以上是Python新手对于sys.argv的一点粗浅认识, 如果有没理解对的地方, 欢迎各位指正.