models.py 文件源码

def create_modifications(cls, instance, previous, current):

        prev = defaultdict(lambda: None, previous)
        curr = defaultdict(lambda: None, current)

        # Compute difference between previous and current
        diffkeys = set([k for k in prev if prev[k] != curr[k]])
        in_previous_not_current = set([k for k in prev if k not in curr])
        in_current_not_previous = set([k for k in curr if k not in prev])

        diffkeys = diffkeys.union(in_previous_not_current).union(in_current_not_previous)
        current_datetime = timezone.now()

        for key in diffkeys:
            FieldModification.objects.create(
                field_name=key,
                previous_value=prev[key],
                current_value=curr[key],
                content_object=instance,
                created=current_datetime,
            )