有人能給我一個例子，這個腳本？ django

Question

我在網上發現了一個腳本，它可以幫助我更改登錄名，以便同時使用用戶名和電子郵件，而不僅僅是用戶名，但有很多部分我不太瞭解。

就像我理解每一行的意思，但我不明白爲什麼這樣做會使我的登錄工作與電子郵件。

class EmailBackend(object): 
    def authenticate(self, username=None, password=None): 
     user_cls = get_user_model() 
     try: 
      user = user_cls.objects.get(email=username) 
      if user.check_password(password): 
       return user 
     except user_cls.DoesNotExist: 
      return None 
     except: 
      return None 

    def get_user(self, user_id): 
     user_cls = get_user_model() 
     try: 
      return user_cls.objects.get(pk=user_id) 
     except user_cls.DoesNotExist: 
      return None 

在此先感謝。

Answer 1

檢查意見： -

class EmailBackend(object): 
    def authenticate(self, username=None, password=None): 
     user_cls = get_user_model() #Getting user object in one variable 

     try: 
      user = user_cls.objects.get(email=username) #Check any user exist with input email(username) with database email(consider as an username) 
      if user.check_password(password): #if user match then check is password match or not 
       return user #If both email and password match then return user information 
     except user_cls.DoesNotExist: #if user not exist then return None 
      return None 
     except: #got any error in middle return None 
      return None 

    def get_user(self, user_id): 
     user_cls = get_user_model() #Get user object in one variable 
     try: 
      return user_cls.objects.get(pk=user_id) #check user with this user_id exist or not, may be PK (some unique id consider as an user_id) 
     except user_cls.DoesNotExist: #if user_id(PK) not exist return None 
      return None