# Dive Into Python Python from novice to pro | Find:

## 11.10. Summary

The `openanything.py` and its functions should now make perfect sense.

There are 5 important features of HTTP web services that every client should support:

- Identifying your application by setting a proper `User-Agent`.
- Handling permanent redirects properly.
- Supporting `Last-Modified` date checking to avoid re-downloading data that hasn't changed.
- Supporting `ETag` hashes to avoid re-downloading data that hasn't changed.
- Supporting gzip compression to reduce bandwidth even when data has changed.