[PyMOL] Number of bonds separating two atoms

Dear PyMOL Users,

I am looking for a command which can determine the separation of two
atoms in terms of chemical bonds. I would like to use it in a script to
assign atom types for peptide molecules. Does any of you have an idea
for that?

Thanks in advance,

Andras Wacha

-- 
András Ferenc Wacha, PhD
research fellow, CREDO instrument responsible

Biological Nanochemistry Research Group

Institute of Materials and Environmental Chemistry
Research Centre for Natural Sciences
Hungarian Academy of Sciences (RCNS HAS)
Magyar tudósok körútja 2.
H-1117 Budapest, Hungary
Phone: +36-1-382-6427
Web: http://bionano.ttk.mta.hu, 
CREDO SAXS instrument: http://credo.ttk.mta.hu