Hi , I am a few days into learning to use the cctbx libraries. My interests are mostly to be able to write scripts that plot various statistics from mtz files and use things like iotbx.pdb to manipulate coordinate files. While I have managed to write a few scripts and have read the very descriptive examples in the newsletters and the few routines inside of phenix.I have a problem with getting much out of the python interface documentation at the sourceforge site. Say , for a particular class say http://cctbx.sourceforge.net/current/python/iotbx.pdb.atom_selection.html, the documentation gives me a "cache" class __init__ method that says __init__(self, root, wildcard_escape_char=r'\') How do I find out what "root" is in this example. Should I be looking at the c++ code to find out the "types" of these arguments. In addition a few of the auto-generated documentation pages such as http://cctbx.sourceforge.net/current_cvs/python/iotbx.pdb.atom.html return an error page. I just want to know a good way of understanding the varrious interfaces when writing code using cctbx in Python Thanks in advance hari