PyDL consists of Python replacements for functions that are part of the IDL built-in library or part of astronomical IDL libraries. The emphasis is on reproducing results of the astronomical library functions. Only the bare minimum of IDL built-in functions are implemented to support this.

There are four astronomical libraries targeted:

* idlutils: a general suite of tools heavily used by SDSS.
* Goddard utilities: The IDL Astronomy User's Library, maintained by
Wayne Landsman and distributed with idlutils.
* idlspec2d: tools for working with SDSS, BOSS and eBOSS spectroscopic
data.
* photoop: tools for working with SDSS imaging data.
This is the Python 2 version of the package.