注册用户表格django

Question

我正在尝试向生成的“注册”表单添加更多字段，我已经在表单中添加了姓名，姓氏和电子邮件字段，现在我想将要创建的用户添加到组中，但是我不知道该怎么做，下一个是我的代码。

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


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

    class Meta:
        model = User
        fields = (
            'username',
            'first_name',
            'last_name',
            'email',
            'password1',
            'password2'
        )
    def save(self, commit=True):
        user = super(RegistrationForm, self).save(commit=False)
        user.first_name = self.cleaned_data['first_name']
        user.last_name = self.cleaned_data['last_name']
        user.email = self.cleaned_data['email']

        if commit:
            user.save()

        return user

这是我的forms.py 是否知道如何向其中添加用户组？