def conditional_cache_page(timeout, condition, *, cache=None, key_prefix=None):
    """This decorator is exactly like cache_page, but with the option to skip
    the caching entirely.

    The second argument is a callable, ``condition``. It's given the
    request and all further arguments, and if it evaluates to a true-ish
    value, the cache is used.
    """

    def decorator(func):
        def wrapper(request, *args, **kwargs):
            if condition(request, *args, **kwargs):
                response = cache_page(
                    timeout=timeout, cache=cache, key_prefix=key_prefix
                )(func)(request, *args, **kwargs)
                # If you don't want consumers to know that the page is cached, add these:
                # response.headers.pop("Expires")
                # response.headers.pop("Cache-Control")

            return func(request, *args, **kwargs)
        return wrapper
    return decorator