code: def get_user(self, username):
          
          try:
              return self.users[username]
          except Exception as e:
              raise UserDoesntExist(username, self.backend_name)
docs: Get a user's attributes
  
          :param username: 'key' attribute of the user
          :type username: string
          :rtype: dict ( {<attr>: <value>} )
  
          .. warning:: raise UserDoesntExist if user doesn't exist