class ListView

def __init__(self, **kwargs):
    """
    Constructor. Called in the URLconf; can contain helpful extra
    keyword arguments, and other things.
    """
    # Go through keyword arguments, and either save their values to our
    # instance, or raise an error.
    for key, value in kwargs.items():
        setattr(self, key, value)

def _allowed_methods(self):
    return [m.upper() for m in self.http_method_names if hasattr(self, m)]

@classonlymethod
def as_view(cls, **initkwargs):
    """Main entry point for a request-response process."""
    for key in initkwargs:
        if key in cls.http_method_names:
            raise TypeError(
                "The method name %s is not accepted as a keyword argument "
                "to %s()." % (key, cls.__name__)
            )
        if not hasattr(cls, key):
            raise TypeError(
                "%s() received an invalid keyword %r. as_view "
                "only accepts arguments that are already "
                "attributes of the class." % (cls.__name__, key)
            )
    def view(request, *args, **kwargs):
        self = cls(**initkwargs)
        self.setup(request, *args, **kwargs)
        if not hasattr(self, "request"):
            raise AttributeError(
                "%s instance has no 'request' attribute. Did you override "
                "setup() and forget to call super()?" % cls.__name__
            )
        return self.dispatch(request, *args, **kwargs)
    view.view_class = cls
    view.view_initkwargs = initkwargs
    # __name__ and __qualname__ are intentionally left unchanged as
    # view_class should be used to robustly determine the name of the view
    # instead.
    view.__doc__ = cls.__doc__
    view.__module__ = cls.__module__
    view.__annotations__ = cls.dispatch.__annotations__
    # Copy possible attributes set by decorators, e.g. @csrf_exempt, from
    # the dispatch method.
    view.__dict__.update(cls.dispatch.__dict__)
    # Mark the callback if the view class is async.
    if cls.view_is_async:
        markcoroutinefunction(view)
    return view

def dispatch(self, request, *args, **kwargs):
    # Try to dispatch to the right method; if a method doesn't exist,
    # defer to the error handler. Also defer to the error handler if the
    # request method isn't on the approved list.
    if request.method.lower() in self.http_method_names:
        handler = getattr(
            self, request.method.lower(), self.http_method_not_allowed
        )
    else:
        handler = self.http_method_not_allowed
    return handler(request, *args, **kwargs)

def get(self, request, *args, **kwargs):
    self.object_list = self.get_queryset()
    allow_empty = self.get_allow_empty()
    if not allow_empty:
        # When pagination is enabled and object_list is a queryset,
        # it's better to do a cheap query than to load the unpaginated
        # queryset in memory.
        if self.get_paginate_by(self.object_list) is not None and hasattr(
            self.object_list, "exists"
        ):
            is_empty = not self.object_list.exists()
        else:
            is_empty = not self.object_list
        if is_empty:
            raise Http404(
                _("Empty list and “%(class_name)s.allow_empty” is False.")
                % {
                    "class_name": self.__class__.__name__,
                }
            )
    context = self.get_context_data()
    return self.render_to_response(context)

def get_allow_empty(self):
    """
    Return ``True`` if the view should display empty lists and ``False``
    if a 404 should be raised instead.
    """
    return self.allow_empty

def get_context_object_name(self, object_list):
    """Get the name of the item to be used in the context."""
    if self.context_object_name:
        return self.context_object_name
    elif hasattr(object_list, "model"):
        return "%s_list" % object_list.model._meta.model_name
    else:
        return None

def get_ordering(self):
    """Return the field or fields to use for ordering the queryset."""
    return self.ordering

def get_paginate_by(self, queryset):
    """
    Get the number of items to paginate by, or ``None`` for no pagination.
    """
    return self.paginate_by

def get_paginate_orphans(self):
    """
    Return the maximum number of orphans extend the last page by when
    paginating.
    """
    return self.paginate_orphans

def get_paginator(
    self, queryset, per_page, orphans=0, allow_empty_first_page=True, **kwargs
):
    """Return an instance of the paginator for this view."""
    return self.paginator_class(
        queryset,
        per_page,
        orphans=orphans,
        allow_empty_first_page=allow_empty_first_page,
        **kwargs,
    )

def get_queryset(self):
    """
    Return the list of items for this view.
    The return value must be an iterable and may be an instance of
    `QuerySet` in which case `QuerySet` specific behavior will be enabled.
    """
    if self.queryset is not None:
        queryset = self.queryset
        if isinstance(queryset, QuerySet):
            queryset = queryset.all()
    elif self.model is not None:
        queryset = self.model._default_manager.all()
    else:
        raise ImproperlyConfigured(
            "%(cls)s is missing a QuerySet. Define "
            "%(cls)s.model, %(cls)s.queryset, or override "
            "%(cls)s.get_queryset()." % {"cls": self.__class__.__name__}
        )
    ordering = self.get_ordering()
    if ordering:
        if isinstance(ordering, str):
            ordering = (ordering,)
        queryset = queryset.order_by(*ordering)
    return queryset

def http_method_not_allowed(self, request, *args, **kwargs):
    logger.warning(
        "Method Not Allowed (%s): %s",
        request.method,
        request.path,
        extra={"status_code": 405, "request": request},
    )
    response = HttpResponseNotAllowed(self._allowed_methods())
    if self.view_is_async:
        async def func():
            return response
        return func()
    else:
        return response

def options(self, request, *args, **kwargs):
    """Handle responding to requests for the OPTIONS HTTP verb."""
    response = HttpResponse()
    response.headers["Allow"] = ", ".join(self._allowed_methods())
    response.headers["Content-Length"] = "0"
    if self.view_is_async:
        async def func():
            return response
        return func()
    else:
        return response

def paginate_queryset(self, queryset, page_size):
    """Paginate the queryset, if needed."""
    paginator = self.get_paginator(
        queryset,
        page_size,
        orphans=self.get_paginate_orphans(),
        allow_empty_first_page=self.get_allow_empty(),
    )
    page_kwarg = self.page_kwarg
    page = self.kwargs.get(page_kwarg) or self.request.GET.get(page_kwarg) or 1
    try:
        page_number = int(page)
    except ValueError:
        if page == "last":
            page_number = paginator.num_pages
        else:
            raise Http404(
                _("Page is not “last”, nor can it be converted to an int.")
            )
    try:
        page = paginator.page(page_number)
        return (paginator, page, page.object_list, page.has_other_pages())
    except InvalidPage as e:
        raise Http404(
            _("Invalid page (%(page_number)s): %(message)s")
            % {"page_number": page_number, "message": str(e)}
        )

def render_to_response(self, context, **response_kwargs):
    """
    Return a response, using the `response_class` for this view, with a
    template rendered with the given context.
    Pass response_kwargs to the constructor of the response class.
    """
    response_kwargs.setdefault("content_type", self.content_type)
    return self.response_class(
        request=self.request,
        template=self.get_template_names(),
        context=context,
        using=self.template_engine,
        **response_kwargs,
    )

def setup(self, request, *args, **kwargs):
    """Initialize attributes shared by all view methods."""
    if hasattr(self, "get") and not hasattr(self, "head"):
        self.head = self.get
    self.request = request
    self.args = args
    self.kwargs = kwargs