问Django脆表单-在home.html中创建一个表单并得到一个错误

EN

Failed lookup for key [form] in "[{'True': True, 'False': False, 'None': None}, {}, {}, {'view': <django.views.generic.base.TemplateView object at 0x10faa03c8>, 'home_url': '/'}]"

from django import forms

from crispy_forms.helper import FormHelper
from crispy_forms.layout import Submit, Layout, Field
from crispy_forms.bootstrap import (
    PrependedText, PrependedAppendedText, FormActions)

class SimpleForm(forms.Form):
    username = forms.CharField(label="Username", required=True)
    password = forms.CharField(
        label="Password", required=True, widget=forms.PasswordInput)
    remember = forms.BooleanField(label="Remember Me?")

    helper = FormHelper()
    helper.form_method = 'POST'
    helper.add_input(Submit('login', 'login', css_class='btn-primary'))

class CartForm(forms.Form):
    item = forms.CharField()
    quantity = forms.IntegerField(label="Qty")
    price = forms.DecimalField()

    helper = FormHelper()
    helper.form_method = 'POST'
    helper.layout = Layout(
        'item',
        PrependedText('quantity', '#'),
        PrependedAppendedText('price', '$', '.00'),
        FormActions(Submit('login', 'login', css_class='btn-primary'))
    )


class CreditCardForm(forms.Form):
    fullname = forms.CharField(label="Full Name", required=True)
    card_number = forms.CharField(label="Card", required=True, max_length=16)
    expire = forms.DateField(label="Expire Date", input_formats=['%m/%y'])
    ccv = forms.IntegerField(label="ccv")
    notes = forms.CharField(label="Order Notes", widget=forms.Textarea())

    helper = FormHelper()
    helper.form_method = 'POST'
    helper.form_class = 'form-horizontal'
    helper.label_class = 'col-sm-2'
    helper.field_class = 'col-sm-4'
    helper.layout = Layout(
        Field('fullname', css_class='input-sm'),
        Field('card_number', css_class='input-sm'),
        Field('expire', css_class='input-sm'),
        Field('ccv', css_class='input-sm'),
        Field('notes', rows=3),
        FormActions(Submit('purchase', 'purchase', css_class='btn-primary'))
    )

from django.views.generic import FormView
from forms import SimpleForm, CreditCardForm, CartForm

class MainView(FormView):
    template_name = "pages/home.html"
    form_class = SimpleForm

from django.conf import settings
from django.conf.urls import include, url
from django.conf.urls.static import static
from django.contrib import admin
from django.views.generic import TemplateView
from django.views import defaults as default_views

urlpatterns = [
    url(r'^$', TemplateView.as_view(template_name='pages/home.html'), name='home'),
    url(r'^page/$', TemplateView.as_view(template_name='pages/page.html'), name='page'),

    # Django Admin, use {% url 'admin:index' %}
    url(settings.ADMIN_URL, admin.site.urls),

    # User management
    url(r'^users/', include('base_django_template.users.urls', namespace='users')),
    url(r'^accounts/', include('allauth.urls')),

    # Your stuff: custom urls includes go here


] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

if settings.DEBUG:
    # This allows the error pages to be debugged during development, just visit
    # these url in browser to see how these error pages look like.
    urlpatterns += [
        url(r'^400/$', default_views.bad_request, kwargs={'exception': Exception('Bad Request!')}),
        url(r'^403/$', default_views.permission_denied, kwargs={'exception': Exception('Permission Denied')}),
        url(r'^404/$', default_views.page_not_found, kwargs={'exception': Exception('Page not Found')}),
        url(r'^500/$', default_views.server_error),
    ]
    if 'debug_toolbar' in settings.INSTALLED_APPS:
        import debug_toolbar
        urlpatterns = [
            url(r'^__debug__/', include(debug_toolbar.urls)),
        ] + urlpatterns

<section id="contact" class="contact">
  <div class="container">
    <div class="row">

      {% crispy form %}

    </div>
  </div>
</section>