python 3 - 如何将命令行参数中的“\\”保存为原始字符串

Question

Code is very simple:

import sys
for arg in sys.argv:
    print(arg)

When I run it using:

myProgram.py \\

It prints:

C:\myProgram.py
\\

Since "\\" is special, under the hood, python addes extra "\\"s so the inputed "\\\\" becomes "\\\\\\\\", and when it prints it becames to "\\\\" again. How can I stop this, or delete the extra "\\"s added by python? So when the inputed argument is "\\\\", it prints "\\"; and when the inputed argument is "\\t", it prints a [tab]; "\\n" to print a new line; etc?

My search leads me to try the "raw string", so I changed my code to

import sys
for arg in sys.argv:
    arg.replace(r'\\',r'\')
    print(arg)

But it throws error saying

SyntaxError: EOL while scanning string literal

Seems the "raw string" is not working here?

UPDATE: Screenshot with slight change

Answer 1

You want to evaluate argument as string, so you can use eval

import sys
for arg in sys.argv:
    print(eval('"' + arg.replace('"', '\\"') + '"'))

WARNING: you should not use this approach in production, because Eval really is dangerous

Answer 2

我认为这个问题在本FAQ中有解释