# Python 3 Support

As of Haystack v2.1.0, it has been ported to support both Python 2 & Python 3 within the same codebase. This builds on top of what six & Django provide.

No changes are required for anyone running an existing Haystack installation. The API is completely backward-compatible, so you should be able to run your existing software without modification.

Virtually all tests pass under both Python 2 & 3, with a small number of expected failures under Python (typically related to ordering, see below).

## Supported Backends

The following backends are fully supported under Python 3. However, you may need to update these dependencies if you have a pre-existing setup.

- Solr (pysolr>=3.1.0)

- Elasticsearch

## Notes

### Testing

If you were testing things such as the query generated by a given `SearchQuerySet` or how your forms would render, under Python 3.3.2+, hash randomization is in effect, which means that the ordering of dictionaries is no longer consistent, even on the same platform.

Haystack took the approach of abandoning making assertions about the entire structure. Instead, we either simply assert that the new object contains the right things or make a call to `sorted(...)` around it to ensure order. It is recommended you take a similar approach.