Basis for a web-requests based Upwork API for Python

UpworkAPI.py

import requests
import logging

from bs4 import BeautifulSoup

logger = logging.getLogger("upwork-api")

class UpworkAPI(object):
    _LOGIN_URL = "https://www.upwork.com/ab/account-security/login"

    _HEADERS = {
        'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.90 Safari/537.36',
        'Origin': 'https://www.upwork.com',
        'Upgrade-Insecure-Requests': '1',
        'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
    }

    def __init__(self, username, password):
        self.logged_in = False

        self.username = username
        self.password = password
        self._session = requests.Session()

        self._setup()

    def _setup(self):
        self._session.headers.update(self._HEADERS)
        self.logged_in = self._login()

        if not self.logged_in is True:
            raise Exception("Login to upwork was unsuccessful!")

    def _login(self):
        headers = self._HEADERS.copy()

        headers.update({
            'Referer': 'https://www.upwork.com/ab/account-security/login',
            'Content-Type': 'application/x-www-form-urlencoded',
            'Accept-Language': 'en-GB,en-US;q=0.8,en;q=0.6',
        })

        request = self._session.get(url=self._LOGIN_URL)
        html = request.text

        soup = BeautifulSoup(html, 'html.parser')

        try:
            login_token = soup.find("input", {'id': 'login__token'}).get('value')
        except:
            return False

        login_request = self._session.post(
            url=self._LOGIN_URL,
            data={
                'login[_token]': login_token,
                'login[iovation]': '',
                'login[password]': self.password,
                'login[redir]': '/home',
                'login[username]': self.username
            }
        )

        if "FindWorkHomeUI" in login_request.text:
            print("Logged In Successfully")
            return True

        print("Failed to Login")
        return False

now this snippet not working