Django的 - get_by_natural_key（）到底需要3個參數（2給出）

Question

我試圖創建一個用戶登錄，但是當我去登錄我收到錯誤消息：

TypeError: get_by_natural_key() takes exactly 3 arguments (2 given) 

There was a similar question asked before, but it never got resolved

。

我不知道它要求的第三個參數是什麼。我簡直就是從Django自己的用戶管理器複製粘貼get_by_natural_key，並將其放入我自己的自定義模型中。

這裏是我的用戶模型：

class CustomUserManager(models.Manager): 
    def get_absolute_url(self): 
     return "/u/%s/" % urlquote(self.username) 

    def get_username(self): 
     'Returns the username' 
     return self.username 

    def get_full_name(self): 
     """ 
     #Returns the first_name plus the last_name, with a space in between. 
     """ 
     full_name = '%s %s' % (self.first_name, self.last_name) 
     return full_name.strip() 

    def get_short_name(self): 
     " Returns the short name for the user." 
     return self.first_name 

    def _create_user(self, username, email, password, **extra_fields): 
     """ 
     Creates and saves a User with the given username, email and  password. 
    """ 
     if not username: 
      raise ValueError('The given username must be set') 
     email = self.normalize_email(email) 
     user = self.model(username=username, email=email, **extra_fields) 
     user.set_password(password) 
     user.save(using=self._db) 
     return user 

    def create_user(self, username, email=None, password=None, **extra_fields): 
     extra_fields.setdefault('is_staff', False) 
     extra_fields.setdefault('is_superuser', False) 
     return self._create_user(username, email, password, **extra_fields) 

    def create_superuser(self, username, email, password, **extra_fields): 
     extra_fields.setdefault('is_staff', True) 
     extra_fields.setdefault('is_superuser', True) 

     if extra_fields.get('is_staff') is not True: 
      raise ValueError('Superuser must have is_staff=True.') 
     if extra_fields.get('is_superuser') is not True: 
      raise ValueError('Superuser must have is_superuser=True.') 

     return self._create_user(username, email, password, **extra_fields) 

    @classmethod 
    def normalize_email(cls, email): 
     """ 
     Normalize the address by lowercasing the domain part of the email 
     address. 
     """ 
     email = email or '' 
     try: 
      email_name, domain_part = email.strip().rsplit('@', 1) 
     except ValueError: 
      pass 
     else: 
      email = '@'.join([email_name, domain_part.lower()]) 
     return email 

    def get_by_natural_key(self, username, password): 
     return self.get(username=username, password=password) 


class CustomUser(AbstractBaseUser, PermissionsMixin): 
    email = models.EmailField('email address', unique=True, db_index=True) 
    username = models.CharField('username', max_length=50, unique=True, db_index=True) 
    first_name = models.CharField(max_length=50, blank=False) 
    last_name = models.CharField(max_length=50, blank=False) 
    joined = models.DateTimeField(auto_now_add=True) 
    is_active = models.BooleanField(default=True) 
    is_admin = models.BooleanField(default=False) 
    date_joined = models.DateTimeField(_('date joined'), default=timezone.now) 

    USERNAME_FIELD = 'username' 
    REQUIRED_FIELDS = [] 

    objects = CustomUserManager() 

    def __unicode__(self): 
     return self.username 

    class Meta: 
     unique_together = (('username', 'password'),) 

views.py

def register_user(request): 
    if request.method == 'POST': 
     form = RegistrationForm(request.POST)  # create form object 
     if form.is_valid(): 
      form.save() 
      return HttpResponseRedirect('/all') 
    args = {} 
    args.update(csrf(request)) 
    args['form'] = RegistrationForm() 
    print args 
    return render(request, 'register.html', args) 


def login(request): 
    """ 
    User Log in View 
    """ 
    if request.method == 'POST': 
     form = AuthenticationForm(data=request.POST) 
     if form.is_valid(): 
      CustomUser = authenticate(username=request.POST['username'], password=request.POST['password']) 
      if CustomUser is not None: 
       if CustomUser.is_active: 
        django_login(request, CustomUser) 
        return redirect('all_posts.html') 
    else: 
     form = AuthenticationForm() 
    return render_to_response('login.html', { 
    'authenticationform': form, 
    }, context_instance=RequestContext(request)) 

Answer 1

Django自己get_by_natural_key方法只需要username說法 - 你的方法期待一個username以及一個password（不知道你從哪裏複製它）。從documentation：

get_by_natural_key(username)

檢索利用USERNAME_FIELD提名的字段的內容的用戶實例。

放下你password說法，它應該工作（它並沒有真正使任何意義的密碼無論如何獲取）：

def get_by_natural_key(self, username): 
    return self.get(username=username) 

更妙的是，你爲什麼不只是繼承BaseUserManager代替重新實現其邏輯？您目前正在繼承models.Manager。