fields.py 文件源码

def _get_subfield_superclass():
    # hardcore trick to support django < 1.3 - there was something wrong with
    # inheritance and SubfieldBase before django 1.3
    # see https://github.com/django/django/commit/222c73261650201f5ce99e8dd4b1ce0d30a69eb4
    if django.VERSION < (1,3):
        return models.Field
    return six.with_metaclass(models.SubfieldBase, models.Field)