json loads throwing error

[mpsameer]

Hi All,

I have python code written using netmiko library which does SSH to a switch and run the command "show env power | json". I need to convert this out put to json format so that I can track individual keys to check the power supply status.

arista_commands = ["show env power | json"]

print("Device is Arista")
        for command in arista_commands:
                print("No of working PSU's on: " + ssh1.send_command(command))
                psu_data = json.loads(ssh1.send_command(command))

Error:
Traceback (most recent call last):
  File "/home/smulgund/device_psu_test.py", line 33, in <module>
    psu_data = json.loads(ssh1.send_command(command))
  File "/usr/local/lib/python3.9/json/__init__.py", line 346, in loads
    return _default_decoder.decode(s)
  File "/usr/local/lib/python3.9/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/local/lib/python3.9/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)

Yoriz write Jan-21-2024, 09:20 AM:
Please post all code, output and errors (in its entirety) between their respective tags. Refer to BBCode help topic on how to post. Use the "Preview Post" button to make sure the code is presented as you expect before hitting the "Post Reply/Thread" button.

[mpsameer]

I am getting error message while convertign the string data to JSON using json.loads().

[mpsameer]

Error:
Traceback (most recent call last):
  File "/home/smulgund/device_psu_test.py", line 33, in <module>
    psu_data = json.loads(ssh1.send_command(command))
  File "/usr/local/lib/python3.9/json/__init__.py", line 346, in loads
    return _default_decoder.decode(s)
  File "/usr/local/lib/python3.9/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/local/lib/python3.9/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)

[deanhystad]

What is returned by ssh1.send_command("show env power | json")? According to the error message it is a json string.

[mpsameer]

the output returned from ssh1.send_command("show env power | json") is class str

[snippsat]

the output returned from ssh1.send_command("show env power | json") is class str

As mention you most make a variable and post what the result is.
It most return a valid json string for json.load() to work.

arista_commands = ["show env power | json"]
for command in arista_commands:
    raw_output = ssh1.send_command(command)
    print(raw_output) # Most return a valid json string 

To give a example on how a valid json string looks.

>>> import json
>>> raw_output = '{"name":"John", "age":30, "city":"New York"}'
>>> data = json.loads(raw_output)
>>> data
{'age': 30, 'city': 'New York', 'name': 'John'}
>>> data['city']
'New York'

[deanhystad]

the output returned from ssh1.send_command("show env power | json") is class str

All json format strings are instances of str, but not all str object are json format strings. Your string is not a json format string. Get the string and print the string. It will look nothing like a json string.

[mpsameer]

print("No of working PSU's on: " + ssh1.send_command(command))
                psu_data = ssh1.send_command(command)
                print(type(psu_data))

This returns type as

Output:
<class 'str'>

[deanhystad]

What is the value of psu_data?