Сергей Горностаев

from copy import deepcopy

def copy_instance_state(src_obj, dst_obj, field_map={}):
    for src_field_name in dir(src_obj):
        if src_field_name.startswith('__'):
            continue
        dst_field_name = src_field_name if src_field_name not in field_map else field_map[src_field_name]
        setattr(dst_obj, dst_field_name, deepcopy(getattr(src_obj, src_field_name)))

class A:
    a = 1
    b = 2
    c = 3

class B:
    a = 0
    b = 0
    z = 0

a = A()
b = B()

copy_instance_state(a, b, {'c': 'z'})

with recursive r as (
    select
      id, parent_id, name
    from catalog_category
    where id = 8
  union
    select
      cc.id, cc.parent_id, cc.name
    from catalog_category as cc
    join r
      on cc.parent_id = r.id
)
select id, name from r where id <> 8;

<!-- Статический импорт с помощью директивы -->
<%@ include file="filename" %>

<!-- Динамический импорт с помощью тега -->
<jsp:include page="filename"/>

<!-- Импорт с помощью JSTL -->
<c:import url="filename" />

import views
urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^$', views.index),
]

from itertools import product
d = {
    'param_abdomen': ['thin', 'normal', 'large'],
    'param_chest': ['strong', 'normal', 'corpulent'],
    'param_shoulders': ['straight', 'normal', 'fallen'],
    'param_stance': ['straight', 'normal', 'curved']
}
keys = sorted(d)
variants = [dict(zip(keys, p)) for p in product(*(d[k] for k in keys))]

@require_POST
@login_required
@transaction.atomic()
@reversion.create_revision()
def add_something(request):
    form = SomeModelForm(request.POST)
    if form.is_valid():
        instance = form.save()
        reversion.set_user(request.user)
        reversion.set_comment(u'Что-то добавлено')
        return redirect(instance)
    else:
        return render(request, 'form.html', {'form': form})

versions = Version.objects.get_for_object(instance)
for n, version in enumerate(versions, start=1):
    print(u'В версии №{} от {}'.format(n, version.revision.date_created))
    for field_name, field_value in version.field_dict.items():
        print(u'поле "{}" имело значение "{}"'.format(field_name, field_value))
    print()

versions = Version.objects.get_for_object(instance)
versions[0].revision.revert()

class MessageView(CreateView):
    model = Message
    form_class = MessageForm
    template_name = 'mssgs/message_form.html'
    success_url = 'messages'

    def get_initial(self):
        initial = super(MessageView, self).get_initial()
        group_id = self.kwargs['group']
        initial['group'] = Group.objects.get(pk=group_id)
        return initial

<property name="hibernate.hbm2ddl.auto">create</property>