import requests

def ping():

    req_str = f'https://developerhub.alfabank.by:8273/partner/1.0.1/public/nationalRates{code_str}{date_str}'
    data = {}
    headers = {
        'content-type': 'application/json'
    }

    try:
        msg = f'GET {req_str}'
        print(msg)
        res = requests.get(req_str, data=data, headers=headers)
        msg = f'answer received = {str(res)}'
        print(msg)
    except Exception as e:
        msg = f'Exception GET {req_str} = {str(e)} ({str(res)})'
        print(msg)
        res = None