from django.conf import settings
from django.views.decorators.cache import cache_page

if settings.DEBUG:
    def cache_page(delay):
        def rendered(view):
            def inner(request, *args, **kwargs):
                return view(request, *args, **kwargs)
            return inner
        return rendered

@cache_page(60 * 60) # 1 hour
def my_view(request):
    ...expensive calculation...