code: def _get_user_id_from_name(self, context_id, user_name):
          
          users = self.zap.users.users_list(context_id)
          for user in users:
              if user['name'] == user_name:
                  return user['id']
  
          raise ZAPError('No user with the name "{0}"" was found for context {1}'.format(user_name, context_id))
docs: Get a user ID from the user name.