python - Simple JSON Decode Error in Gemini API Started Out of Nowhere

Question

I am trying to play with the Gemini trading API. I have issued myself an API key and a secret, and after configuring my environment, in which I had a lot of issues setting up and installing requests through pip, I used their example code to create a simple script to read my recent trades. Here is the script, minus my API keys:

#!/usr/bin/env/ python

import requests
import json
import base64
import hmac
import hashlib
import datetime, time

url = "https://api.sandbox.gemini.com"

gemini_api_key = "master-xxx"
gemini_api_secret = "xxx".encode()

t = datetime.datetime.now()
payload_nonce =  str(int(time.mktime(t.timetuple())*1000))
payload =  {"request": "/v1/mytrades", "nonce": payload_nonce}
encoded_payload = json.dumps(payload).encode()
b64 = base64.b64encode(encoded_payload)
signature = hmac.new(gemini_api_secret, b64, hashlib.sha384).hexdigest()

request_headers = {
    'Content-Type': "text/plain",
    'Content-Length': "0",
    'X-GEMINI-APIKEY': gemini_api_key,
    'X-GEMINI-PAYLOAD': b64,
    'X-GEMINI-SIGNATURE': signature,
    'Cache-Control': "no-cache"
    }

response = requests.post(url, headers=request_headers)

my_trades = response.json()
print(my_trades)

Now at first, it would run, but give me an error saying I hadn't specified an account. Then, without changing ANYTHING AT ALL, it suddenly quit working altogether. So while I still have some sort of issue accessing the API, I can't even get to the errors anymore to try to figure out why. Now what I get is a JSON decode error, which looks like the following:

Traceback (most recent call last):
  File "c:UsersdavidDesktopCode ProjectsGeminiTraderGeminiTrader-v0.1.py", 
line 33, in <module>
    my_trades = response.json()
  File "C:UsersdavidAppDataLocalProgramsPythonPython39libsite-packages
equests-2.25.1-py3.9.egg
equestsmodels.py", line 900, in json
    return complexjson.loads(self.text, **kwargs)
  File "C:UsersdavidAppDataLocalProgramsPythonPython39libjson\__init__.py", line 346, in loads
    return _default_decoder.decode(s)
  File "C:UsersdavidAppDataLocalProgramsPythonPython39libjsondecoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "C:UsersdavidAppDataLocalProgramsPythonPython39libjsondecoder.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)

What is causing this json decode issue? Why was it not coming up before, when the API was simply rejecting my request due to an account parameter error? Why did it suddenly change to this error without me modifying anything in the code? How can I fix it? I kept having issues with installing requests and getting it to work, maybe I messed something up in that process?

Certainly after fixing this I will have a new host of issues to fix because the documentation on this API is abysmal. Any help in progressing this project would be greatly appreciated! Thanks!

Answer 1

As you are calling an API, there are chances that your API call fails and returns just string or empty response. I would suggest that you first add a check on the status code of your response something like below and then process the json data.

    data = requests.post() 
    if data.status_code != 200:
        raise Exception("Error", data.reason) 
   json_data = data.json()