How to convert input arguments to program as json in python-CodePudding

Here is my code

import json
import sys

def main():
    payloads=sys.argv[2]
    payloads=payloads.replace(",",",\"")
    payloads=payloads.replace(":","\":")
    payloads=payloads.replace("{","{\"")
    z=json.loads("'" payloads "'")
    print(payloads)

if __name__ == "__main__":
    main()

The input can not be changed as its auto generated and I need to parse it inside the python code to get individual values. How can this be done, p.s. I am not python expert

When i try to run it in command prompt as below (in single line):

python test.py payload: "{"temperature":20,"humidity":80,"pressure":1000,"timestamp":1652419592750,"deviceid":"device1"}"

I see below error:

Traceback (most recent call last):
  File "test.py", line 14, in <module>
    main()
  File "test.py", line 10, in main
    z=json.loads("'" payloads "'")
  File "python3\lib\json\__init__.py", line 346, in loads
    return _default_decoder.decode(s)
  File "python3\lib\json\decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "python3\lib\json\decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

CodePudding user response：

Put single quotes around the argument, then all the double quotes will be preserved, and you don't need to do any replacing in Python.

import json
import sys

def main():
    payloads=sys.argv[2]
    z=json.loads(payloads)
    print(payloads)

if __name__ == "__main__":
    main()

python test.py payload: '{"temperature":20,"humidity":80,"pressure":1000,"timestamp":1652419592750,"deviceid":"device1"}'

CodePudding user response：

The easyest way to solve your problem would be to add good quotes to the input but if you can't, you can use this

import json, sys

def main():
    payloads=sys.argv[2]
    payloads=payloads.replace(",",",\"")
    payloads=payloads.replace(":","\":")
    payloads=payloads.replace("{","{\"")


    for x in payloads.split(","):
        
        value = x.split(":")[1].replace("}", "")

        try:
            int(value)
            float(value)
            assert value not in ("true", "false", "null")

        except (AssertionError, ValueError):
            new = x.replace(value, f'"{value}"')
            payloads = payloads.replace(x, new)

    
    z=json.loads(payloads)
    print(payloads)

if __name__ == "__main__":
    main()

note however that this way can cause a lot of bugs if your input data ever contains the characters }, : or ,