update coinbase pro DCA for Python 3

script.py

# secrets
API_KEY = "something"
API_PASS = "something else"
API_SECRET = "also something else"

# boilerplate
import requests
import json, hmac, hashlib, time, requests, base64
from requests.auth import AuthBase


class CoinbaseExchangeAuth(AuthBase):
    def __init__(self, api_key, secret_key, passphrase):
        self.api_key = api_key
        self.secret_key = secret_key
        self.passphrase = passphrase

    def __call__(self, request):
        timestamp = str(time.time())
        # add ascii fix
        message = bytes(timestamp + request.method + request.path_url, "ascii") + (
            request.body or ""
        )
        hmac_key = base64.b64decode(self.secret_key)
        signature = hmac.new(hmac_key, message, hashlib.sha256)
        # add b"\n" and update encoding of digest
        signature_b64 = base64.b64encode(signature.digest()).rstrip(b"\n")

        request.headers.update(
            {
                "CB-ACCESS-SIGN": signature_b64,
                "CB-ACCESS-TIMESTAMP": timestamp,
                "CB-ACCESS-KEY": self.api_key,
                "CB-ACCESS-PASSPHRASE": self.passphrase,
                "Content-Type": "application/json",
            }
        )
        return request


api_url = "https://api.pro.coinbase.com/"
auth = CoinbaseExchangeAuth(API_KEY, API_SECRET, API_PASS)

# logic
order = {
    "funds": 10,
    "type": "market",
    "side": "buy",
    "product_id": "BTC-USD",
}
r = requests.post(api_url + "orders", json=order, auth=auth)
print(r.json())