Monkeypatch Django 1.5's QuerySet adding a .first() method compatible with 1.6

monkeypatch_queryset.py

def monkeypatch_queryset_first():
    """ Monkeypatch QuerySet adding a `.first()` method which is compatible
        with Django 1.6's `.first()`. """
    from django.db.models.query import QuerySet
    if hasattr(QuerySet, "first"):
        import warnings
        warnings.warn("QuerySet.first is already defined! "
                      "Monkey patch should be removed.")
        return
    def first(self):
        """
        Returns the first object of a query, returns None if no match is found.
        """
        qs = self if self.ordered else self.order_by('pk')
        try:
            return qs[0]
        except IndexError:
            return None
    QuerySet.first = first

monkeypatch_queryset_first()