Removed unnecessary code-block directives.

docs/topics/class-based-views/mixins.txt

@@ -222,9 +222,9 @@ we'll want the functionality provided by
 We'll demonstrate this with the ``Author`` model we used in the
 :doc:`generic class-based views introduction<generic-display>`.
 
-.. code-block:: python
+.. snippet::
+    :filename: views.py
 
-    # views.py
     from django.http import HttpResponseForbidden, HttpResponseRedirect
     from django.core.urlresolvers import reverse
     from django.views.generic import View
@@ -253,9 +253,11 @@ look up the author we're interested in, which it just does with a simple call
 to ``self.get_object()``. Everything else is taken care of for us by the
 mixin.
 
-We can hook this into our URLs easily enough::
+We can hook this into our URLs easily enough:
+
+.. snippet::
+    :filename: urls.py
 
-    # urls.py
     from django.conf.urls import url
     from books.views import RecordInterest
 
@@ -519,9 +521,7 @@ The ``AuthorDisplay`` view is almost the same as :ref:`when we
 first introduced AuthorDetail<generic-views-extra-work>`; we have to
 write our own ``get_context_data()`` to make the
 ``AuthorInterestForm`` available to the template. We'll skip the
-``get_object()`` override from before for clarity.
-
-.. code-block:: python
+``get_object()`` override from before for clarity::
 
     from django.views.generic import DetailView
     from django import forms
@@ -542,9 +542,7 @@ Then the ``AuthorInterest`` is a simple :class:`FormView`, but we
 have to bring in :class:`~django.views.generic.detail.SingleObjectMixin` so we
 can find the author we're talking about, and we have to remember to set
 ``template_name`` to ensure that form errors will render the same
-template as ``AuthorDisplay`` is using on ``GET``.
-
-.. code-block:: python
+template as ``AuthorDisplay`` is using on ``GET``::
 
     from django.core.urlresolvers import reverse
     from django.http import HttpResponseForbidden
@@ -573,9 +571,7 @@ based view, so we can do that at the point we choose between the two subviews.
 You can of course pass through keyword arguments to
 :meth:`~django.views.generic.base.View.as_view()` in the same way you
 would in your URLconf, such as if you wanted the ``AuthorInterest`` behavior
-to also appear at another URL but using a different template.
-
-.. code-block:: python
+to also appear at another URL but using a different template::
 
     from django.views.generic import View