Print rotor count distribution

A program that prints the rotorcount distribution for a database of molecules. It uses OEIsRotor functor to determine if a bond is freely rotatable. Use the OEGetRotatableBondCount function to get a more precise count of rotatable bonds in a molecule.

Example

prompt > rotorcount.py input.oeb.gz

Code

Download code

rotorcount.py

#!/usr/bin/env python
# (C) 2022 Cadence Design Systems, Inc. (Cadence) 
# All rights reserved.
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# subject to these terms. Cadence claims no rights to Customer's
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# NOT LIMITED TO, WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
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# or its use.

#############################################################################
# Counts the number of rotatable bonds in the input compound file and
# outputs the maximum number of rotamers and the rotomer distribution
#############################################################################
import sys
from openeye import oechem


def CountRotors(ifs):
    rotcounts = []
    for mol in ifs.GetOEMols():
        nrots = oechem.OECount(mol, oechem.OEIsRotor())
        while nrots >= len(rotcounts):
            rotcounts.append(0)
        rotcounts[nrots] += 1

    print("Max rotors:", len(rotcounts) - 1)
    print("Rotorcount distribution:")

    for rots, numrot in enumerate(rotcounts):
        print("\t%d:\t%d" % (rots, numrot))


def main(argv=[__name__]):
    if len(argv) != 2:
        oechem.OEThrow.Usage("%s <infile>" % argv[0])

    ifs = oechem.oemolistream()
    if not ifs.open(argv[1]):
        oechem.OEThrow.Fatal("Unable to open %s for reading" % argv[1])

    CountRotors(ifs)


if __name__ == "__main__":
    sys.exit(main(sys.argv))

See also

• OEIsRotor functor

• OEGetRotatableBondCount function