如何在ModelForm中添加密码占位符？

Django 1.11
我想以我拥有的所有形式添加一个占位符，
我想知道密码字段为何具有（无值）？这是要澄清的图像。在这里输入图片说明，我需要知道如何通过表格添加密码占位符。

表格

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


class UserForm(forms.ModelForm):
    password = forms.CharField(widget=forms.PasswordInput)

    class Meta:
        model = User
        fields = ['username', 'email', 'password']


class EditForm(UserForm):
    def __init__(self, form):
        super(EditForm, self).__init__(form)
        for key, field in self.fields.items():
            if isinstance(field.widget, forms.TextInput) or \
               isinstance(field.widget, forms.EmailInput) or \
               isinstance(field.widget, forms.PasswordInput):
                   field.widget.attrs.update({'placeholder': field.label})

register.html

{% extends 'base.html' %}

{% block title %} Register {% endblock %}

{% block body %}
    <div class="register">
        <div class="container">
            <h1>Register</h1>
            <form method="post">
                {% csrf_token %}
                    {{ form.as_p }}
                <button type="submit">Registier</button>
            </form>
        </div>
    </div>

{% endblock %}

views.py

from django.shortcuts import render, redirect
from django.contrib.auth.forms import UserCreationForm
from django.views import View
from .forms import UserForm, EditForm
from django.contrib.auth import authenticate



def index(request):
    return render(request, 'account/index.html')


class UserRegister(View):
    form_class = EditForm
    template_name = 'account/register.html'

    def get(self, request):
        form = self.form_class(None)
        return render(request, self.template_name, {'form': form})

    def post(self, request):
        form = self.form_class(request.POST)
        if form.is_valid():
            user = form.save(commit=False)
            username = form.cleaned_data['username']
            password = form.cleaned_data['password']
            email = form.cleaned_data['email']
            user.set_password(password)
            user.save()

            user = authenticate(username=username, email=email, password=password)
            return redirect('account:home')
        return render(request, self.template_name, {'form': form})