bitcoin json rpc with python requests module?

Question

I've been trying for hours, and I just don't know what I'm doing wrongly. It's just for planning/research (not performant) -- playing around with some code from github -- but I need to see it functional.

RPC_USER = username
RPC_PASS = pasword
rpc_id =  ID HERE
jsonrpc = "2.0"
payload = {"jsonrpc": jsonrpc, "id": rpc_id, "method": method, "params": params}
authstr = base64.encodestring(bytes('%s:%s' % (RPC_USER, RPC_PASS), 'utf-8')).strip() 
request_headers = {"Authorization": "Basic %s" % authstr, 'content-type': 'application/json'}
try:
    response = requests.get(RPC_URL, headers = request_headers, data = json.dumps(payload)).json()
    print(response['result'])      
except Exception as e: print(str(e))
if response['id'] != rpc_id:
        raise ValueError("invalid response id!")

I get an error as follows:

Here's the whole traceback:

Expecting value: line 1 column 1 (char 0) # prints the Exception

Traceback (most recent call last): 
  File "miner_2017.py", line 411, in <module>
    solo_miner(bin2hex("------coinbase message here -----"), "-----bitcoin address here-----")
  File "miner_2017.py", line 401, in solo_miner
    mined_block, hps = block_mine(rpc_getblocktemplate(), coinbase_message, 0, address, timeout=60)
  File "miner_2017.py", line 63, in rpc_getblocktemplate
    try: return rpc("getblocktemplate", [{}])
  File "miner_2017.py", line 52, in rpc
    if response['id'] != rpc_id:
UnboundLocalError: local variable 'response' referenced before assignment  

Which after doing some looking seems to be a problem with decoding the json object from a bytes object rather than a string object. I don't know how to fix this. It seems the "response" variable assignment was unsuccessful due to the json problem. How can I get the json object in string form from the request?

Would somebody help me out? Thanks

Answer 1

#!/usr/bin/env python

import getpass
import json
import requests    

def instruct_wallet(method, params):
    url = "http://127.0.0.1:8332/"
    payload = json.dumps({"method": method, "params": params})
    headers = {'content-type': "application/json", 'cache-control': "no-cache"}
    try:
        response = requests.request("POST", url, data=payload, headers=headers, auth=(rpc_user, rpc_password))
        return json.loads(response.text)
    except requests.exceptions.RequestException as e:
        print e
    except:
        print 'No response from Wallet, check Bitcoin is running on this machine'

rpc_user='foo'
rpc_password='bar'
passphrase = getpass.getpass('Enter your wallet passphrase: ')
timeout = raw_input('Unlock for how many seconds: ')

answer = instruct_wallet('walletpassphrase', [passphrase, timeout])
if answer['error'] != None:
    print answer['error']
else:
    print answer['result']

I'm using something similar for Altcoins