code: def login(self):
          
          if self.__logged_in:
              return
          login = {'userId': self.__username, 'userPassword': self.__password}
          header = BASE_HEADERS.copy()
          request = requests.post(BASE_URL + 'login',
                                  data=login,
                                  headers=header,
                                  timeout=10)
  
          try:
              result = request.json()
          except ValueError as error:
              raise Exception(
                  "Not a valid result for login, " +
                  "protocol error: " + request.status_code + ' - ' +
                  request.reason + "(" + str(error) + ")")
  
          if 'error' in result.keys():
              raise Exception("Could not login: " + result['error'])
  
          if request.status_code != 200:
              raise Exception(
                  "Could not login, HTTP code: " +
                  str(request.status_code) + ' - ' + request.reason)
  
          if 'success' not in result.keys() or not result['success']:
              raise Exception("Could not login, no success")
  
          cookie = request.headers.get("set-cookie")
          if cookie is None:
              raise Exception("Could not login, no cookie set")
  
          self.__cookie = cookie
          self.__logged_in = True
          return self.__logged_in
docs: Login to Tahoma API.