# Example for: restraints.pick(), restraints.condense()

# This will pick only restraints that include at least one
# mainchain (CA, N, C, O) atom and write them to a file.

from modeller import *
from modeller.scripts import complete_pdb

log.verbose()
env = Environ()
env.io.atom_files_directory = ['../atom_files']
env.libs.topology.read(file='$(LIB)/top_heav.lib')
env.libs.parameters.read(file='$(LIB)/par.lib')

mdl = complete_pdb(env, '1fas')

allsel = Selection(mdl)
mdl.restraints.make(allsel, restraint_type='stereo', spline_on_site=False)
allsel.energy()

atmsel = allsel.only_atom_types('CA N C O')
mdl.restraints.pick(atmsel, restraint_sel_atoms=1)
# Delete the unselected restraints from memory:
mdl.restraints.condense()
atmsel.energy()

mdl.restraints.write(file='1fas.rsr')