Simple example (CLI) of how to get MegaFon balance data. Required `requests` and `baker`, but can be made without them easily. *Megafon is a Russian mobile carrier*.

megabalance.py

#!/usr/bin/env python
# coding: utf-8
import os
import requests
import baker
from xml.etree import ElementTree

BALANCE_URL = 'https://moscowsg.megafon.ru/MEGAFON_BALANCE/MGFSTF_GET_BALANCE'


@baker.command(default=True, params={
	'msisdn': "Mobile phone number in `9261234567` format",
	'password': "Service Guide password (call the number `*105*00#`)"
})
def balance(msisdn=None, password=None):
	msisdn = os.environ.get('MEGABALANCE_MSISDN', msisdn)
	password = os.environ.get('MEGABALANCE_PASSWORD', password)
	if msisdn is None or password is None:
		return "No `msisdn` and/or `password` provided."
	headers = {
		'content-type': "application/x-www-form-urlencoded"
	}
	params = {
		'MSISDN': msisdn,
		'PASSWORD': password,
	}
	response = requests.get(BALANCE_URL, params=params, headers=headers)
	if not response.ok:
		response.raise_for_status()
	xml = ElementTree.fromstring(response.text)
	return "{balance:.2f} rub".format(balance=float(xml.find("./GET_BALANCE/BALANCE").text))

if __name__ == '__main__':
	baker.run()

It’s highly outdated and doesn’t work anymore (for a few years maybe), but if there’re any new balance widgets (e.g. for macOS’ dashboard) by Megafon, then they can be used to find a new endpoint and data format.