import requests
import http.cookiejar
jar = http.cookiejar.CookieJar()
login_url = 'https://www.fitbit.com/login'
acc_pwd = {'login': 'Log In', 'email': 'username', 'password': 'pwd',
    'disableThirdPartyLogin': 'false', 'loginRedirect': '',
    'includeWorkflow': '', 'login': 'Log In'}
r = requests.get(login_url, cookies=jar)
r = requests.post(login_url, cookies=jar, data=acc_pwd)
Python: войдите на веб-сайт, используя urllib