JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Your code produced an empty response body, you'd want to check for that or catch the exception raised. It is possible the server responded with a 204 No Content response, or a non-200-range status code was returned (404 Not Found, etc.). Check for this.

Note:

• There is no need to use simplejson library, the same library is included with Python as the json module.

• There is no need to decode a response from UTF8 to unicode, the simplejson / json .loads() method can handle UTF8 encoded data natively.

• pycurl has a very archaic API. Unless you have a specific requirement for using it, there are better choices.

Either the requests or httpx offers much friendlier APIs, including JSON support. If you can, replace your call with:

import requests

response = requests.get(url)
response.raise_for_status()  # raises exception when not a 2xx response
if response.status_code != 204:
    return response.json()

Of course, this won't protect you from a URL that doesn't comply with HTTP standards; when using arbirary URLs where this is a possibility, check if the server intended to give you JSON by checking the Content-Type header, and for good measure catch the exception:

if (
    response.status_code != 204 and
    response.headers["content-type"].strip().startswith("application/json")
):
    try:
        return response.json()
    except ValueError:
        # decide how to handle a server that's misbehaving to this extent

Be sure to remember to invoke json.loads() on the contents of the file, as opposed to the file path of that JSON:

json_file_path = "/path/to/example.json"

with open(json_file_path, 'r') as j:
     contents = json.loads(j.read())

I think a lot of people are guilty of doing this every once in a while (myself included):

contents = json.loads(json_file_path)

Check the response data-body, whether actual data is present and a data-dump appears to be well-formatted.

In most cases your json.loads- JSONDecodeError: Expecting value: line 1 column 1 (char 0) error is due to :

• non-JSON conforming quoting
• XML/HTML output (that is, a string starting with <), or
• incompatible character encoding

Ultimately the error tells you that at the very first position the string already doesn't conform to JSON.

As such, if parsing fails despite having a data-body that looks JSON like at first glance, try replacing the quotes of the data-body:

import sys, json
struct = {}
try:
  try: #try parsing to dict
    dataform = str(response_json).strip("'<>() ").replace('\'', '\"')
    struct = json.loads(dataform)
  except:
    print repr(resonse_json)
    print sys.exc_info()

Note: Quotes within the data must be properly escaped

With the requests lib JSONDecodeError can happen when you have an http error code like 404 and try to parse the response as JSON !

You must first check for 200 (OK) or let it raise on error to avoid this case. I wish it failed with a less cryptic error message.

NOTE: as Martijn Pieters stated in the comments servers can respond with JSON in case of errors (it depends on the implementation), so checking the Content-Type header is more reliable.

Check encoding format of your file and use corresponding encoding format while reading file. It will solve your problem.

with open("AB.json", encoding='utf-8', errors='ignore') as json_data:
     data = json.load(json_data, strict=False)