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Sorry I'm not an expert in python. Could someone explain me the behavior of the following code:

import sys

def send_cmd():

    param = r'--password="some\"pass"'

    print >> sys.stdout, param

    cmd = [
        '--adminName', 'admin',
        param,
        '--host', '127.0.0.1',
    ]

    print >> sys.stdout, cmd

if __name__ == "__main__":
    send_cmd()

The output that I get is the following:

--password="some\"pass"
['--adminName', 'admin', '--password="some\\"pass"', '--host', '127.0.0.1']

So when I assign raw value to the variable I get a single backslash, but when I put this var to array, it converts string to have double backslashes. But I would want to keep the value as it is - raw with a single backslash. How can I achieve this?

Thanks.

UPD:

The actual issue happens when I try to get password value in Java application. Python passes cmd to java in the form:

jar javaApp --adminName admin --password="some\\"pass"--host 127.0.0.1

And inside java application I use org.apache.commons.cli.CommandLine.getOptionValue("--password") Which returns me "some(double backslash)"pass" and that java cannot escape double quote

UPD2:

Ok, so it turns out that python is not an issue actually. The problem is that CommandLineParser (LenientPosixParser) cannot correctly parse argument passed with escape character. So when I pass to command line:

--password "some\"pass"

CommandLineParser returns "some"pass" value without trimming surrounding quotes and is not escaping double quote char.

alexlys
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  • Does this answer your question? [How to get rid of double backslash in python windows file path string?](https://stackoverflow.com/questions/11924706/how-to-get-rid-of-double-backslash-in-python-windows-file-path-string) – Yevhen Kuzmovych Oct 11 '21 at 14:21
  • You probably want to store `'--password'` and `'some"pass'` as two separate elements of `cmd`. `cmd` itself probably should *not* be converted to a string at all, but used as-is with a command like `subprocess.run`. – chepner Oct 11 '21 at 14:29
  • I've updated the description, I'm using --param="value" pattern since password is passed through command line and it can contain leading dashes "-" and other types of special symbols. – alexlys Oct 11 '21 at 14:44

2 Answers2

0

Python does not keep track if the string was initially defined with the r prefix.

The value is always the same, it is just a matter of the representation when you print the value.

Compare:

>>> param = r'--password="some\"pass"'
>>> param
'--password="some\\"pass"'
>>> print(param)
--password="some\"pass"
>>> print(repr(param))
'--password="some\\"pass"'
>>> param == r'--password="some\"pass"'
True
>>> param == '--password="some\\"pass"'
True
Mike Scotty
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  • Actually after I pass this value to the java command to the with sp.Popen, it comes like "some\\"pass". For the purpose of parameters parsing I use org.apache.commons.cli.CommandLine.getOptionValue method and it returns the following value "some\\"pass". So java cannot interpret double backslash as an escape symbol – alexlys Oct 11 '21 at 14:35
0

I don't know why it does this but you can do it using for loop iterate through cmd and output each string

for i in cmd:
    sys.stdout.write(i+' ')
Ishfaq Khawaja
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