[cctbxbb] getting resolution for any "h" "k" "l" and cctbx

Hi , I have been programming in python for a little bit, I am new to cctbx . My crystallography knowledge is as good as solving a few structures gives you. I have a few questions. 1) I was wondering if someone can point me to routines available from cctbx modules that can give me the "resolution" for a given index "h" "k" "l". in any space group 2) In addition , if someone can point me in the direction of a well illustrated depiction of the derivation of the reciprocal lattice for the triclinic case , that will be very much appreciated bonus . Thank you in advance Hari