有代码吗

以下是一个使用Django框架实现的用户登录和注册系统的示例代码：

首先，在Django的settings.py文件中添加以下配置：

# settings.py

# 加密密钥
SECRET_KEY = 'your-secret-key'

# 注册app
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'account',  # 注册的app
]

# 数据库设置
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'your-database-name',
        'USER': 'your-database-user',
        'PASSWORD': 'your-database-password',
        'HOST': 'your-database-host',
        'PORT': 'your-database-port',
    }
}

# 认证系统设置
AUTH_USER_MODEL = 'account.User'
LOGIN_URL = '/login/'
LOGIN_REDIRECT_URL = '/'

接下来，创建一个account app，并在models.py文件中定义用户模型和用户管理器：

# models.py

from django.db import models
from django.contrib.auth.models import AbstractBaseUser, BaseUserManager


class UserManager(BaseUserManager):
    def create_user(self, email, username, password=None):
        if not email:
            raise ValueError('Users must have an email address')

        user = self.model(
            email=self.normalize_email(email),
            username=username,
        )

        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_superuser(self, email, username, password):
        user = self.create_user(
            email=self.normalize_email(email),
            username=username,
            password=password,
        )
        user.is_admin = True
        user.save(using=self._db)
        return user


class User(AbstractBaseUser):
    email = models.EmailField(max_length=255, unique=True)
    username = models.CharField(max_length=30, unique=True)
    is_active = models.BooleanField(default=True)
    is_admin = models.BooleanField(default=False)

    objects = UserManager()

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['username']

    def __str__(self):
        return self.email

    def has_perm(self, perm, obj=None):
        return True

    def has_module_perms(self, app_label):
        return True

    @property
    def is_staff(self):
        return self.is_admin

接下来，在views.py文件中编写登录和注册的视图函数：

# views.py

from django.shortcuts import render, redirect
from django.contrib.auth import authenticate, login
from .forms import RegistrationForm


def register(request):
    if request.method == 'POST':
        form = RegistrationForm(request.POST)
        if form.is_valid():
            form.save()
            return redirect('/')
    else:
        form = RegistrationForm()

    return render(request, 'account/register.html', {'form': form})


def user_login(request):
    if request.method == 'POST':
        email = request.POST.get('email')
        password = request.POST.get('password')
        user = authenticate(request, email=email, password=password)

        if user is not None:
            login(request, user)
            return redirect('/')
        else:
            return render(request, 'account/login.html', {'error': 'Invalid email or password'})
    else:
        return render(request, 'account/login.html')

最后，在forms.py文件中编写注册表单的验证逻辑：

# forms.py

from django import forms
from django.contrib.auth.forms import UserCreationForm
from .models import User


class RegistrationForm(UserCreationForm):
    email = forms.EmailField(required=True)

    class Meta:
        model = User
        fields = ('email', 'username', 'password1', 'password2')

    def save(self, commit=True):
        user = super(RegistrationForm, self).save(commit=False)
        user.email = self.cleaned_data['email']
        if commit:
            user.save()
        return user

这样，一个基本的用户登录和注册系统就完成了。您可以按照自己的需求进行修改和扩展。