# How to separate bad data records from good data?

**URL:** <https://discourse.greatexpectations.io/t/how-to-separate-bad-data-records-from-good-data/358>\
**Category:** Archive\
**Tags:** how-to\
**Created:** [August 28, 2020, 6:03pm UTC](https://discourse.greatexpectations.io/t/how-to-separate-bad-data-records-from-good-data/358 "2020-08-28T18:03:45Z")\
**Posts on this page:** 1\
**Showing post:** 3

<div class="post-metadata">

**Author:** ![bhcastleton](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.greatexpectations.io/bhcastleton/32/73_2.png) [@bhcastleton](https://discourse.greatexpectations.io/u/bhcastleton)\
**Post date:** [February 19, 2021, 7:22pm UTC](https://discourse.greatexpectations.io/t/how-to-separate-bad-data-records-from-good-data/358/3 "2021-02-19T19:22:01Z")

</div>

Also, here’s a toy example for doing this using pandas. It is not implemented for sql.

> [@How can I use the return\_format unexpected\_index\_list to select row from a PandasDataSet](https://discourse.greatexpectations.io/t/how-can-i-use-the-return-format-unexpected-index-list-to-select-row-from-a-pandasdataset/70):
>
> Im looking to provide unexpected index list as a parameter for the next task in my data pipeline in airflow or dagster.

---

_[View the full topic](https://discourse.greatexpectations.io/t/how-to-separate-bad-data-records-from-good-data/358)._