"obabel ... -f # -l #" - Split Large Molecule File

This section provides tutorial examples on how to extract a chunk of molecules from a large molecule file with Open Babel 'obabel' command option arguments.

If you have a large molecule file with thousands of molecules, you can use Open Babel "obabel" command to extract a chunk of molecules to the output using the "-f #" and "-l #" options.

The "-f #" option specifies the index of the first molecule to be extracted.

The "-l #" option specifies the index of the last molecule to be extracted.

For example, the following "obabel" command extract 100 molecules from a large file starting at molecule # 101.

herong$ obabel molecules.sdf -O molecules-chunk.sdf -f 101 -l 200

100 molecules converted

For example, the following "obabel" command extract the first molecule from a large file:

herong$ obabel molecules.sdf -O molecule-first.sdf -f 1 -l 1

1 molecule converted

Table of Contents

 About This Book

 SMILES (Simplified Molecular-Input Line-Entry System)

 Open Babel: The Open Source Chemistry Toolbox

Using Open Babel Command: "obabel"

 What Is "obabel" Command

 "obabel -i ..." - Input Data Format and Source

 "obabel -o ... -O" - Output Data Format and Destination

 "obabel -... --..." - Generic Conversion Options

 "obabel" Command Option Argument Syntax

 "obabel ... --gen2D" - Calculated 2D Coordinates

"obabel ... -f # -l #" - Split Large Molecule File

 "obabel -h/-d" - Add/Remove Hydrogens in Molecule Data

 "obabel --append ..." - Calculate Molecule Properties

 "obabel -L formats" - List of File Formats Supported

 "obabel -a..." - Extra Options for Input Reading

 "obabel -x..." - Extra Options for Output Writing

 "obabel" vs. "babel" Open Babel Commands

 Generating SVG Pictures with Open Babel

 Substructure Search with Open Babel

 Similarity Search with Open Babel

 Fingerprint Index for Fastsearch with Open Babel

 Stereochemistry with Open Babel

 Command Line Tools Provided by Open Babel

 RDKit: Open-Source Cheminformatics Software

 rdkit.Chem.rdchem - The Core Module

 rdkit.Chem.rdmolfiles - Molecular File Module

 rdkit.Chem.rdDepictor - Compute 2D Coordinates

 rdkit.Chem.Draw - Handle Molecule Images

 Molecule Substructure Search with RDKit

 rdkit.Chem.rdmolops - Molecule Operations

 Daylight Fingerprint Generator in RDKit

 Morgan Fingerprint Generator in RDKit

 RDKit Performance on Substructure Search

 Introduction to Molecular Fingerprints

 OCSR (Optical Chemical Structure Recognition)

 AlphaFold - Protein Structure Prediction

 Resources and Tools

 Cheminformatics Related Terminologies

 References

 Full Version in PDF/EPUB