Django form 里 password1 password2 验证先后探索（注册表单）

from __future__ import unicode_literals

import unicodedata

from django import forms
from django.contrib.auth import (
    authenticate, get_user_model, password_validation,
)
from django.forms.widgets import TextInput


class UsernameField(forms.CharField):
    def to_python(self, value):
        return unicodedata.normalize('NFKC', super(UsernameField, self).to_python(value))


class UserRegisterForm(forms.ModelForm):
    """
    学生注册表单
    """
    password1 = forms.CharField(
        label="确认密码",
        widget=forms.PasswordInput(attrs={'class': 'form-control', 'placeholder': '请输入确认密码'}),
        strip=False,
        help_text="请输入确认密码")

    password2 = forms.CharField(
        label="确认密码",
        widget=forms.PasswordInput(attrs={'class': 'form-control', 'placeholder': '请输入确认密码'}),
        strip=False,
        help_text="请输入确认密码",
    )

    class Meta:
        model = User
        fields = ("username",)
        field_classes = {'username': UsernameField}
        widgets = {
            'username': TextInput(attrs={'class': 'form-control', 'placeholder': '请输入您的姓名'}),
        }

    def clean_password2(self):
        password1 = self.cleaned_data.get("password1")
        password2 = self.cleaned_data.get("password2")
        print("p2---\n",type(password2), password2)
        if password1 and password2 and password1 != password2:
            raise forms.ValidationError("两次密码不一致")
        # self.instance.username = self.cleaned_data.get('username')
        # password_validation.validate_password(self.cleaned_data.get('password2'), self.instance)
        return password2

System check identified no issues (0 silenced).
March 06, 2020 - 18:47:27
Django version 2.2.7, using settings 'StudentsManager.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.
p2---
 {'username': '张4全', 'password1': 'django123456'}
p2 <class 'NoneType'> None
[06/Mar/2020 18:47:36] "POST /register HTTP/1.1" 200 2192