I want to write a python/pymol  script that will give me residue -residue distances within a pdb file programmatically 

I know that within pymol I can get a distance object using

select r55 , chain A and resi 55
select r 22 , chain A and resi 22

distance (r55) ,(r22)

This creates the dist01 object . If I wanted to do this using a python script and get a pretty print of all the distances in the distance object , how do I do that?
Also pointers to other python toolkits that can allow me to make such measurements outside pymol will be greatly appreciated.

Thanks for your help