code: def nonnull_fields(obj, pretty=True):
      
      return PrettyDict((k, v) for k, v in [(f.attname, getattr(obj, f.attname, None))
                        for f in obj._meta.fields] if (
                              v and
                              v not in NULL_VALUES and
                              stringify(v).strip().lower()[:MAX_NULL_REPR_LEN] not in NULL_REPR_VALUES and
                              not is_invalid_date(v)))
docs: Generate `.values()` dict from a table record, removing non-informative values
  
      Noninformative values include:
        date < 1970
        date > 2100
        False
        None
        0
        0.0
        '0'
        '0.0'
        '0.0000'