3、modleForm组件

1、原生form表单

步骤：

1.models.py ...
    makemigrations
    migrate

3.createsuperuser
    yuan yuan1234

    1.addbook:(getlist)
        ...
        publish_id = request.POST.get('publish_id')
        auhtor_pk_list = request.POST.getlist('auhtor_pk_list')  # ['1', '2']
        book_obj = Book.objects.create(title=title,price=price,date=date,publish_id=publish_id)
        book_obj.authors.add(*auhtor_pk_list)

    2.editbook:(set)
        ...
         <p>价格 <input type="text" name="price" value="{{ edit_book.price }}"></p>
        {% if author in edit_book.authors.all %}
            <option selected value="{{ author.pk }}">{{ author.name }}</option>
        {% else %}
            <option value="{{ author.pk }}">{{ author.name }}</option>
        {% endif %}

        ...
        ret = Book.objects.filter(pk=edit_book_id).update(title=title, price=price, date=date, publish_id=publish_id)
        print('ret---', ret)  # 1

        book_obj = Book.objects.filter(pk=edit_book_id).first()
        print('book_obj---', book_obj)  # 对象

        book_obj.authors.set(auhtor_pk_list)

code代码

models

from django.db import models

# Create your models here.

class Book(models.Model):

    title=models.CharField(max_length=32)
    price=models.DecimalField(max_digits=8,decimal_places=2)  # 999999.99
    date=models.DateField()
    publish=models.ForeignKey(to="Publish",on_delete=True)
    authors=models.ManyToManyField("Author")
    def __str__(self):
        return self.title
class Publish(models.Model):
    name=models.CharField(max_length=32)
    def __str__(self):
        return self.name

class Author(models.Model):
    name=models.CharField(max_length=32)
    def __str__(self):
        return self.name

admin.py

from django.contrib import admin

# Register your models here.
from .models import *

admin.site.register(Book)
admin.site.register(Author)
admin.site.register(Publish)

urls

"""formsDemo URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.11/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""

from django.conf.urls import url
from django.contrib import admin

from app01 import views

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^books/', views.books),
    url(r'^book/add', views.addbook),
    url(r'^book/edit/(\d+)', views.editbook),
]

views

from django.shortcuts import render,redirect

# Create your views here.

from .models import *

def books(request):
    book_list=Book.objects.all()
    return render(request,"books.html",locals())

def addbook(request):
    if request.method=="POST":
        title=request.POST.get("title")
        price=request.POST.get("price")
        date=request.POST.get("date")
        publish_id=request.POST.get("publish_id")
        author_pk_list=request.POST.getlist("author_pk_list") # [1,2]

        book_obj=Book.objects.create(title=title,price=price,date=date,publish_id=publish_id)
        book_obj.authors.add(*author_pk_list)

        return redirect("/books/")

    publish_list=Publish.objects.all()
    author_list=Author.objects.all()
    return render(request,"add.html",locals())

def editbook(request,edit_book_id):
    if request.method=="POST":
        title=request.POST.get("title")
        price=request.POST.get("price")
        date=request.POST.get("date")
        publish_id=request.POST.get("publish_id")
        author_pk_list=request.POST.getlist("author_pk_list") # [1,2]

        Book.objects.filter(pk=edit_book_id).update(title=title,price=price,date=date,publish_id=publish_id)
        book_obj=Book.objects.filter(pk=edit_book_id).first()
        book_obj.authors.set(author_pk_list)

        return redirect("/books/")

    edit_book=Book.objects.filter(pk=edit_book_id).first()
    publish_list = Publish.objects.all()
    author_list = Author.objects.all()
    return render(request,"edit.html",locals())

books.html

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<a href="/book/add"><button>添加书籍</button></a>
<hr>
<table border="">
    {% for book in book_list %}
       <tr>
           <td>{{ book.title }}</td>
           <td>{{ book.price }}</td>
           <td>{{ book.date|date:"Y-m-d" }}</td>
           <td>{{ book.publish.name }}</td>
           <td>{{ book.authors.all }}</td>
            <td><a href="/book/edit/{{book.pk}}"><button>编辑</button></a></td>
       </tr>
    {% endfor %}

</table>

</body>
</html>

add.html

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>

<h3>添加页面</h3>

<form action="" method="post">
     {% csrf_token %}
    <p>书籍名称 <input type="text" name="title"></p>
    <p>价格 <input type="text" name="price"></p>
    <p>日期 <input type="date" name="date"></p>
    <p>出版社
        <select name="publish_id" id="">
              {% for publish in publish_list %}
                  <option value="{{ publish.pk }}">{{ publish.name }}</option>
              {% endfor %}

        </select>
    </p>
    <p>作者

        <select name="author_pk_list" id="" multiple>
              {% for author in author_list %}
                  <option value="{{ author.pk }}">{{ author.name }}</option>
              {% endfor %}

        </select>
    </p>
    <input type="submit">
</form>
</body>
</html>

edit.html

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>

<h3>编辑页面</h3>

<form action="" method="post">
     {% csrf_token %}
    <p>书籍名称 <input type="text" name="title" value="{{ edit_book.title }}"></p>
    <p>价格 <input type="text" name="price" value="{{ edit_book.price }}"></p>
    <p>日期 <input type="date" name="date" value="{{ edit_book.date|date:'Y-m-d' }}"></p>
    <p>出版社
        <select name="publish_id" id="">
              {% for publish in publish_list %}

                  {% if edit_book.publish == publish %}
                     <option selected value="{{ publish.pk }}">{{ publish.name }}</option>
                  {% else %}
                      <option value="{{ publish.pk }}">{{ publish.name }}</option>
                  {% endif %}

              {% endfor %}

        </select>
    </p>
    <p>作者

        <select name="author_pk_list" id="" multiple>
              {% for author in author_list %}
                  {% if author in edit_book.authors.all %}
                     <option selected value="{{ author.pk }}">{{ author.name }}</option>
                  {% else %}
                     <option value="{{ author.pk }}">{{ author.name }}</option>
                  {% endif %}

              {% endfor %}

        </select>
    </p>
    <input type="submit">
</form>
</body>
</html>

2、forms组件2

forms组件1：https://www.cnblogs.com/venicid/p/9308074.html

https://www.cnblogs.com/yuanchenqi/articles/7614921.html 
https://www.cnblogs.com/wupeiqi/articles/6144178.html

form组件1：forms组件添加，编辑用原生form表单

form组件2：实现了编辑也用form表单

1、针对form表单设计form组件

　　ChoiceField(Field)
　　ModelChoiceField(ChoiceField)
　　ModelMultipleChoiceField(ModelChoiceField)

2、form组件能做的事情:

form组件能做的事情:
    1.能渲染页面
    2.能做校验用
    3.拿到错误信息显示

3、code

views

from django.shortcuts import render,redirect

# Create your views here.

from .models import *

from django import forms
from django.forms import widgets

class BookForm(forms.Form):
    title = forms.CharField(max_length=32,label="书籍名称")
    price = forms.DecimalField(max_digits=8, decimal_places=2,label="价格")  # 999999.99
    date = forms.DateField(label="日期",
        widget=widgets.TextInput(attrs={"type":"date"})
    )

    #gender=forms.ChoiceField(choices=((1,"男"),(2,"女"),(3,"其他")))
    #publish=forms.ChoiceField(choices=Publish.objects.all().values_list("pk","title"))
    publish=forms.ModelChoiceField(queryset=Publish.objects.all())
    authors=forms.ModelMultipleChoiceField(queryset=Author.objects.all())

def books(request):
    book_list=Book.objects.all()
    return render(request,"books.html",locals())

def addbook(request):
    form = BookForm()
    if request.method == 'POST':
        form = BookForm(request.POST)
        if form.is_valid():
            print(form.cleaned_data)
            """
            clean_date: {'title': '书1', 'price': Decimal('1111'),
                 'date': datetime.date(2018, 6, 7),
                 'publish': <Publish: 香蕉出版社>,   # 对象
                  'authors': <QuerySet [<Author: alex>, <Author: egon>]>}

            """
            title = form.cleaned_data.get('title')
            price = form.cleaned_data.get('price')
            date = form.cleaned_data.get('date')
            publish = form.cleaned_data.get('publish')
            authors = form.cleaned_data.get('authors')

            book_obj = Book.objects.create(title=title,price=price,date=date,publish=publish)
            book_obj.authors.add(*authors)

            return redirect('/books/')
    print(form)
    return render(request,'add.html',locals())

def editbook(request,edit_book_id):
    edit_book = Book.objects.filter(pk=edit_book_id).first()
    form = BookForm(initial={"title": edit_book.title, "price": edit_book.price, "date": edit_book.date,
                             "publish": edit_book.publish, "authors": edit_book.authors.all()})
    if request.method=="POST":
        form = BookForm(request.POST)
        if form.is_valid():
            title = form.cleaned_data.get("title")
            price = form.cleaned_data.get("price")
            date = form.cleaned_data.get("date")
            publish = form.cleaned_data.get("publish")
            authors = form.cleaned_data.get("authors")  # [1,2]

            Book.objects.filter(pk=edit_book_id).update(title=title,price=price,date=date,publish=publish)
            book_obj=Book.objects.filter(pk=edit_book_id).first()
            book_obj.authors.set(authors)

            return redirect("/books/")

    return render(request,"edit.html",locals())

add

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>

<h3>添加页面</h3>

<form action="" method="post" novalidate>
    {% csrf_token %}

    {% for field in form %}
        <div>
            {{ field.label }}
            {{ field }}
            {{ field.errors.0 }}
        </div>
    {% endfor %}

    <input type="submit">
</form>
</body>
</html>

edit

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>

<h3>编辑页面</h3>

<form action="" method="post" novalidate>
    {% csrf_token %}
    {% for field in form %}
        <div>
            {{ field.label }}
            {{ field }}
            {{ field.errors.0 }}
        </div>
    {% endfor %}
    <input type="submit">
</form>
</body>
</html>

4、form组件补充

1、Django内置字段如下：

Field
    required=True,               是否允许为空
    widget=None,                 HTML插件
    label=None,                  用于生成Label标签或显示内容
    initial=None,                初始值
    help_text='',                帮助信息(在标签旁边显示)
    error_messages=None,         错误信息 {'required': '不能为空', 'invalid': '格式错误'}
    show_hidden_initial=False,   是否在当前插件后面再加一个隐藏的且具有默认值的插件（可用于检验两次输入是否一直）
    validators=[],               自定义验证规则
    localize=False,              是否支持本地化
    disabled=False,              是否可以编辑
    label_suffix=None            Label内容后缀

CharField(Field)
    max_length=None,             最大长度
    min_length=None,             最小长度
    strip=True                   是否移除用户输入空白

IntegerField(Field)
    max_value=None,              最大值
    min_value=None,              最小值

FloatField(IntegerField)
    ...

DecimalField(IntegerField)
    max_value=None,              最大值
    min_value=None,              最小值
    max_digits=None,             总长度
    decimal_places=None,         小数位长度

BaseTemporalField(Field)
    input_formats=None          时间格式化   

DateField(BaseTemporalField)    格式：2015-09-01
TimeField(BaseTemporalField)    格式：11:12
DateTimeField(BaseTemporalField)格式：2015-09-01 11:12

DurationField(Field)            时间间隔：%d %H:%M:%S.%f
    ...

RegexField(CharField)
    regex,                      自定制正则表达式
    max_length=None,            最大长度
    min_length=None,            最小长度
    error_message=None,         忽略，错误信息使用 error_messages={'invalid': '...'}

EmailField(CharField)
    ...

FileField(Field)
    allow_empty_file=False     是否允许空文件

ImageField(FileField)
    ...
    注：需要PIL模块，pip3 install Pillow
    以上两个字典使用时，需要注意两点：
        - form表单中 enctype="multipart/form-data"
        - view函数中 obj = MyForm(request.POST, request.FILES)

URLField(Field)
    ...

BooleanField(Field)
    ...

NullBooleanField(BooleanField)
    ...

ChoiceField(Field)
    ...
    choices=(),                选项，如：choices = ((0,'上海'),(1,'北京'),)
    required=True,             是否必填
    widget=None,               插件，默认select插件
    label=None,                Label内容
    initial=None,              初始值
    help_text='',              帮助提示

ModelChoiceField(ChoiceField)
    ...                        django.forms.models.ModelChoiceField
    queryset,                  # 查询数据库中的数据
    empty_label="---------",   # 默认空显示内容
    to_field_name=None,        # HTML中value的值对应的字段
    limit_choices_to=None      # ModelForm中对queryset二次筛选

ModelMultipleChoiceField(ModelChoiceField)
    ...                        django.forms.models.ModelMultipleChoiceField

TypedChoiceField(ChoiceField)
    coerce = lambda val: val   对选中的值进行一次转换
    empty_value= ''            空值的默认值

MultipleChoiceField(ChoiceField)
    ...

TypedMultipleChoiceField(MultipleChoiceField)
    coerce = lambda val: val   对选中的每一个值进行一次转换
    empty_value= ''            空值的默认值

ComboField(Field)
    fields=()                  使用多个验证，如下：即验证最大长度20，又验证邮箱格式
                               fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),])

MultiValueField(Field)
    PS: 抽象类，子类中可以实现聚合多个字典去匹配一个值，要配合MultiWidget使用

SplitDateTimeField(MultiValueField)
    input_date_formats=None,   格式列表：['%Y--%m--%d', '%m%d/%Y', '%m/%d/%y']
    input_time_formats=None    格式列表：['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']

FilePathField(ChoiceField)     文件选项，目录下文件显示在页面中
    path,                      文件夹路径
    match=None,                正则匹配
    recursive=False,           递归下面的文件夹
    allow_files=True,          允许文件
    allow_folders=False,       允许文件夹
    required=True,
    widget=None,
    label=None,
    initial=None,
    help_text=''

GenericIPAddressField
    protocol='both',           both,ipv4,ipv6支持的IP格式
    unpack_ipv4=False          解析ipv4地址，如果是::ffff:192.0.2.1时候，可解析为192.0.2.1， PS：protocol必须为both才能启用

SlugField(CharField)           数字，字母，下划线，减号（连字符）
    ...

UUIDField(CharField)           uuid类型
    ...

2、Django内置插件：

TextInput(Input)
NumberInput(TextInput)
EmailInput(TextInput)
URLInput(TextInput)
PasswordInput(TextInput)
HiddenInput(TextInput)
Textarea(Widget)
DateInput(DateTimeBaseInput)
DateTimeInput(DateTimeBaseInput)
TimeInput(DateTimeBaseInput)
CheckboxInput
Select
NullBooleanSelect
SelectMultiple
RadioSelect
CheckboxSelectMultiple
FileInput
ClearableFileInput
MultipleHiddenInput
SplitDateTimeWidget
SplitHiddenDateTimeWidget
SelectDateWidget

3、常用选择插件：

# 单radio，值为字符串
# user = fields.CharField(
#     initial=2,
#     widget=widgets.RadioSelect(choices=((1,'上海'),(2,'北京'),))
# )

# 单radio，值为字符串
# user = fields.ChoiceField(
#     choices=((1, '上海'), (2, '北京'),),
#     initial=2,
#     widget=widgets.RadioSelect
# )

# 单select，值为字符串
# user = fields.CharField(
#     initial=2,
#     widget=widgets.Select(choices=((1,'上海'),(2,'北京'),))
# )

# 单select，值为字符串
# user = fields.ChoiceField(
#     choices=((1, '上海'), (2, '北京'),),
#     initial=2,
#     widget=widgets.Select
# )

# 多选select，值为列表
# user = fields.MultipleChoiceField(
#     choices=((1,'上海'),(2,'北京'),),
#     initial=[1,],
#     widget=widgets.SelectMultiple
# )

# 单checkbox
# user = fields.CharField(
#     widget=widgets.CheckboxInput()
# )

# 多选checkbox,值为列表
# user = fields.MultipleChoiceField(
#     initial=[2, ],
#     choices=((1, '上海'), (2, '北京'),),
#     widget=widgets.CheckboxSelectMultiple
# )

3、modleForm组件

https://www.cnblogs.com/yuanchenqi/articles/7614921.html
https://www.cnblogs.com/yuanchenqi/articles/8034442.html

1、modleform组件

  1.modelform 组件
        中间转换的组件, 不用自己去写form组件。
        将模型表转换成, 具体的form组件。

  2.fields

3.一对多，多对多，不用考虑！ form.save()

4.BookForm(instance=edit_book) # 接收一个对象

5、  {{ field.label }}{{ field }} {{ field.errors.0 }}

6、扩展modleform

https://www.cnblogs.com/yuanchenqi/articles/8034442.html

from django.shortcuts import render,HttpResponse,redirect
from django.forms import ModelForm
# Create your views here.
from app01 import models
def test(request):
    # model_form = models.Student
    model_form = models.Student.objects.all()
    return render(request,'test.html',{'model_form':model_form})

class StudentList(ModelForm):
    class Meta:
        model = models.Student #对应的Model中的类
        fields = "__all__" #字段，如果是__all__,就是表示列出所有的字段
        exclude = None #排除的字段
        labels = None #提示信息
        help_texts = None #帮助提示信息
        widgets = None #自定义插件
        error_messages = None #自定义错误信息
        #error_messages用法：
        error_messages = {
        'name':{'required':"用户名不能为空",},
        'age':{'required':"年龄不能为空",},
        }
        #widgets用法,比如把输入用户名的input框给为Textarea
        #首先得导入模块
        from django.forms import widgets as wid #因为重名，所以起个别名
        widgets = {
        "name":wid.Textarea
        }
        #labels，自定义在前端显示的名字
        labels= {
        "name":"用户名"
        }
def student(request):
    if request.method == 'GET':
        student_list = StudentList()
        return render(request,'student.html',{'student_list':student_list})
    else:
        student_list = StudentList(request.POST)
        if student_list.is_valid():
            student_list.save()
            return render(request,'student.html',{'student_list':student_list})

def student_edit(request,pk):
    obj = models.Student.objects.filter(pk=pk).first()
    if not obj:
        return redirect('test')
    if request.method == "GET":
        student_list = StudentList(instance=obj)
        return render(request,'student_edit.html',{'student_list':student_list})
    else:
        student_list = StudentList(request.POST,instance=obj)
        if student_list.is_valid():
            student_list.save()
            return render(request,'student_edit.html',{'student_list':student_list})

扩展 modelform

7、modle.EmialField()

       models.CharFiled()
        models.EmailField()  # 为什么，不写charField？ 因为在使用 modelForm 时，可以校验！！这时EmailField才有意义！
        eg:
            models.URLField
            models.UUIDField

8、code

views

from django.shortcuts import render,HttpResponse,redirect

# Create your views here.

from .models import *

from django.forms import ModelForm
from django.forms import widgets as wid  # 因为重名，所以起个别名！

wid_text = wid.TextInput(attrs={'class':'form-control'})
required_msg = {'required':'不能为空'}
class BookForm(ModelForm):
    class Meta:
        model = Book
        fields = "__all__"  # 对所有字段转换
        # fields = ['title','price']

        labels = {"title":"书籍名称","price":"价格","date":"日期","publish":"出版社","authors":"作者"}
        widgets = {
            'title':wid_text,
            'price':wid_text,
            'date':wid.TextInput(attrs={'class':'form-control','type':'date'}),
            'publish':wid.Select(attrs={'class':'form-control'}),
            'authors':wid.SelectMultiple(attrs={'class':'form-control'})
        }
        error_messages = {
            'title':required_msg,
            'price':required_msg,
            'date':{'required':'不能为空','invalid':'格式错误'},
            'publish':required_msg,
            'authors':required_msg,
        }

def books(request):
    book_list = Book.objects.all()

    return render(request,'books.html',locals())

def addbook(request):
    form = BookForm()
    if request.method == 'POST':
        form = BookForm(request.POST)
        if form.is_valid():
            form.save()  # form.model.objects.create(request.POST)
            return redirect('/books/')

    return render(request,'add.html',locals())

def editbook(request, edit_book_id):
    edit_book = Book.objects.filter(pk=edit_book_id).first()
    form = BookForm(instance=edit_book)

    if request.method == 'POST':
        form = BookForm(request.POST,instance=edit_book)
        if form.is_valid():
            form.save()   # edit_book.update(request.POST)
            return redirect('/books/')

    return render(request, 'edit.html', locals())

add.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
     <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

</head>
<body>
<h3>添加页面</h3>

<div class="row">
    <div class="col-md-4 col-md-offset-1">
        {% include 'form.html' %}
    </div>
</div>

</body>
</html>

add.html

edit

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>

<h3>编辑页面</h3>

<div class="row">
    <div class="col-md-4 col-md-offset-1">
        {% include 'form.html' %}
    </div>
</div>

</body>
</html>

form.html

<form action="" method="post" novalidate>
    {% csrf_token %}

    {% for field in form %}
        <p>
            {{ field.label }}
            {{ field }}
            <small><span class="pull-right text-danger has-error">{{ field.errors.0 }}</span></small>
        </p>
    {% endfor %}
    <input type="submit">
</form>

4、前端form表单，后台form组件（可以没有数据库）

前端手写一个form表单，后台使用form组件，进行校验，也是可以的！！

注意： <p>名称 <input type="text" name="title"></p>  和   title = forms.CharField()

name和title对应

views。py

from django import forms

class BookForms(forms.Form):
    title = forms.CharField()
    price = forms.FloatField()

def addbook(request):
    form = BookForms()
    if request.method == 'POST':
        form = BookForms(request.POST)
        # form = BookForm({'title':'php','price':111,'xxx':'egon'})
        if form.is_valid():
            print('clean_data',form.cleaned_data)
            # clean_data {'title': '水浒传', 'price': 123.0}
        else:
            print('error',form.errors)

    return render(request,'addbook.html',locals())

addbook.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<h3>添加书籍</h3>

<form action="" method="post" novalidate>
    {% csrf_token %}
    <p>名称 <input type="text" name="title"></p>
    <p>价格 <input type="text" name="price"></p>
    <p>xxx <input type="text" name="xxx"></p>

    <input type="submit">
</form>

<form action="" method="post" novalidate>
    {% csrf_token %}
    {{ form.as_p }}
    {{ form.as_table }}
    {{ form.as_ul }}
    <input type="submit">
</form>

</body>
</html>

5、django补充 - 请求流程

说明：

django 请求流程图--流程最重要！

http协议 
请求协议：请求首行，请求头，请求体！
响应协议: 响应首行，响应头，响应体！

我们发给浏览器的响应体（html)是一堆 str 浏览器解析(html)才能看到数据！ 

render 对templates 模板渲染！
没有模板 就 httpresponse 返回str  
打开文件 捕获是否模板语法，嵌入{{}} 数据 返回 html（str） response

只要到了 中间件 交给浏览器的 一定已经是一些 html(str) 

1、什么是WSGI？什么是wsgiref？

WSGI（Web Server Common Interface）是专门为Python语言制定的web服务器与应用程序之间的网关接口规范，通俗的来说，只要一个服务器拥有一个实现了WSGI标准规范的模块（例如apache的mod_wsgi模块），那么任意的实现了WSGI规范的应用程序都能与它进行交互。因此，WSGI也主要分为两个程序部分：服务器部分和应用程序部分。 
wsgiref则是官方给出的一个实现了WSGI标准用于演示用的简单Python内置库，它实现了一个简单的WSGI Server和WSGI Application（在simple_server模块中），主要分为五个模块：simple_server， util， headers， handlers， validate。 
wsgiref源码地址：https://pypi.python.org/pypi/wsgiref