from django.db import modelsclass User(models.Model):    """    用户表    """    username = models.CharField(verbose_name=‘用户名‘, max_length=32)    password = models.CharField(verbose_name=‘密码‘, max_length=64)    email = models.EmailField(verbose_name=‘邮箱‘)    def __str__(self):        return self.usernameclass Role(models.Model):    """    角色表    """    caption = models.CharField(verbose_name=‘角色‘, max_length=32)    def __str__(self):        return self.captionclass User2Role(models.Model):    """    用户角色关系表    """    user = models.ForeignKey(User, verbose_name=‘用户‘, related_name=‘roles‘)    role = models.ForeignKey(Role, verbose_name=‘角色‘, related_name=‘users‘)    def __str__(self):        return ‘%s-%s‘ % (self.user.username, self.role.caption,)class Menu(models.Model):    """    菜单表    """    caption = models.CharField(verbose_name=‘菜单名称‘, max_length=32)    parent = models.ForeignKey(‘self‘, verbose_name=‘父菜单‘, related_name=‘p‘, null=True, blank=True)    def __str__(self):        prev = ""        parent = self.parent        while True:            if parent:                prev = prev + ‘-‘ + str(parent.caption)                parent = parent.parent            else:                break        return ‘%s-%s‘ % (prev, self.caption,)class Permission(models.Model):    """    权限    """    caption = models.CharField(verbose_name=‘权限‘, max_length=32)    url = models.CharField(verbose_name=‘URL正则‘, max_length=128)    menu = models.ForeignKey(Menu, verbose_name=‘所属菜单‘, related_name=‘permissions‘,null=True,blank=True)    def __str__(self):        return "%s-%s" % (self.caption, self.url,)class Action(models.Model):    """    操作：增删改查    """    caption = models.CharField(verbose_name=‘操作标题‘, max_length=32)    code = models.CharField(verbose_name=‘方法‘, max_length=32)    def __str__(self):        return self.captionclass Permission2Action2Role(models.Model):    """    权限操作关系表    """    permission = models.ForeignKey(Permission, verbose_name=‘权限URL‘, related_name=‘actions‘)    action = models.ForeignKey(Action, verbose_name=‘操作‘, related_name=‘permissions‘)    role = models.ForeignKey(Role, verbose_name=‘角色‘, related_name=‘p2as‘)    class Meta:        unique_together = (            (‘permission‘, ‘action‘, ‘role‘),        )    def __str__(self):        return "%s-%s-%s" % (self.permission, self.action, self.role,)