使用用户名/邮箱/手机号 + 密码登陆

• 多形式登陆其实很简单就是继承Django中ModelBackend并且重写authenticate()方法

源码分析：

class ModelBackend:
    """
    Authenticates against settings.AUTH_USER_MODEL.
    """

    def authenticate(self, request, username=None, password=None, **kwargs):
        if username is None:
            username = kwargs.get(UserModel.USERNAME_FIELD)
        try:
            user = UserModel._default_manager.get_by_natural_key(username)
        except UserModel.DoesNotExist:
            # Run the default password hasher once to reduce the timing
            # difference between an existing and a nonexistent user (#20760).
            UserModel().set_password(password)
        else:
            if user.check_password(password) and self.user_can_authenticate(user):
                return user

通过查看源码我们可以看到Django默认的认证后端是判断用户的username和password这两个字段是否通过校验，但实际上，我们可能会有更多的登录需求，比如说，既可以通过用户名，也可以通过手机号或邮箱等登录，这时候我们可以重写authenticate()方法实现

1.我们新建一个py文件里面写一个类继承ModelBackend，并且重写authenticate()方法

第一种方法：这种方法通俗简单易懂

# 以前使用username进行用户验证，现在修改成email|phone进行验证 多形式登录
from user.models import User

class EmailAuthBackend:
    def authenticate(self, request, username=None, password=None):
        try:
            user = User.objects.get(username=username)
        except Exception as e:
            user = None
        if not user:
            try:
                user = User.objects.get(email=username)

            except Exception as e:
                user = None
        if not user:
            try:
                user = User.objects.get(phone=username)

            except Exception as e:
                user = None

        if user and user.check_password(password):
            return user
        else:
            return None

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

第二种方法：使用Q对象。（ | ）来获取username phone email

from django.contrib.auth.backends import ModelBackend
from user import models
from django.db.models import Q


class MultiformAuthBackend(ModelBackend):
    def authenticate(self, request, username=None, password=None, **kwargs):
        try:
            user = User.objects.get(Q(username=username) | Q(phone=username) | Q(email=username))
            if user is not None and user.check_password(password):
                return user
        except Exception as e:
            print(e)

2.在setting.py配置文件

• 完成自定义的认证后端之后，我们还需要在配置文件里告诉Django要使用我们自定义的而不是默认的认证后端

# 自定义验证后端 多形式登录
# AUTHENTICATION_BACKENDS = [‘user.utils.EmailAuthBackend‘]
AUTHENTICATION_BACKENDS = [‘user.utils.MultiformAuthBackend‘]

其他类似链接参考：
【Django】创建用户，继承AbstractUser自定义用户模型类
【Django】自定义存储后端返回完整图片的URL链接

使用用户名/邮箱/手机号 + 密码登陆 多形式登陆