Get customer emails from Merit using Merit API

merit-api-get-customer-emails.py

import hmac
import datetime
import json
from base64 import b64encode
from urllib.parse import urlencode

import requests

API_KEY = b'...'
API_ID = '...'
API_BASE_URL = 'https://aktiva.merit.ee/api/v1/'
API_GET_CUSTOMERS_URL = API_BASE_URL + 'getcustomers'


def calculate_signature(timestamp):
    data_string = API_ID + timestamp
    hash_obj = hmac.new(key=API_KEY, msg=data_string.encode('ascii'), digestmod='sha256')
    return b64encode(hash_obj.digest())

def get_query_params():
    timestamp = datetime.datetime.now().strftime('%Y%m%d%H%M%S')
    signature = calculate_signature(timestamp)
    return {
        'ApiId': API_ID,
        'timestamp': timestamp,
        'signature': signature,
    }

def get_customer_emails_from_merit():
    query_params = get_query_params()
    customers = requests.get(API_GET_CUSTOMERS_URL + '?' + urlencode(query_params)).text
    return {c['Email'] for c in json.loads(customers)
            if c['Contact'] != 'ARCHIVED' and c['Email'] is not None}

if __name__ == '__main__':
    print(get_customer_emails_from_merit())