Python Poloniex API Call - python-3.x

Question

I have the following code that I am trying to make an API call to Poloniex according to their instructions
import urllib
import urllib.request
import json
import time
import hashlib
import codecs
import hmac
import time
Key = "whatever your key is"
Sign = "whatever your secret is"
def returnBalances(balances):
nonce = int(round(time.time()-599900000)*10)
parms = {"returnBalances":balances,
"nonce":nonce}
parms = urllib.parse.urlencode(parms)
hashed = hmac.new(b'Sign',digestmod=hashlib.sha512)
signature = hashed.hexdigest()
headers = {"Content-type":"application/x-www-form-urlencoded",
"Key":Key,
"Sign":signature}
conn = urllib.request.urlopen("https://poloniex.com")
conn.request("POST","/tradingApi",parms,headers)
response = conn.getresponse()
print(response.status,response.reason)
returnBalances('balances')
When I run this I get this error message
HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 403: Forbidden
Can someone please help?

Answer 1

You can catch HTTP errors with urllib.error.HTTPError
POST data should be bytes, so you have to encode parms
urllib.request.urlopen returns a HTTPResponse object, which has no request method.
If you want to set headers and other parameters you should use urllib.request.Request
According to the api docs the post parameters should be 'nonce' and 'command', so i modified your function to accept 'returnBalances' as a parameter and use it in parms["command"]
def api_call(command):
nonce = int(round(time.time()-599900000)*10)
parms = {"command":command, "nonce":nonce}
parms = urllib.parse.urlencode(parms).encode()
hashed = hmac.new(Sign.encode(), parms, digestmod=hashlib.sha512)
signature = hashed.hexdigest()
headers = {"Key":Key, "Sign":signature}
req = urllib.request.Request("https://poloniex.com/tradingApi", headers=headers)
try:
conn = urllib.request.urlopen(req, data=parms)
except urllib.error.HTTPError as e:
conn = e
print(conn.status,conn.reason)
return json.loads(conn.read().decode())
balances = api_call("returnBalances")