bioscons extends SCons for building reproducible bioinformatics pipelines, with built-in support for the Slurm job scheduler.

• Dependency tracking: only re-run steps whose inputs have changed
• Slurm integration: dispatch jobs to a cluster with a single drop-in replacement
• Parallelization: dependency graph enables concurrent execution of independent steps

Why SCons?

SCons is well-suited for bioinformatics pipelines:

• Incremental builds: re-running SCons only re-executes steps whose inputs have changed
• Parallelization: the dependency graph enables concurrent execution of independent steps
• Shell-like syntax: external programs are easy to invoke with variable substitution
• Python integration: leverage the standard library, Biopython, NumPy, etc. directly in your build script
• File objects: pipeline steps are expressed in terms of file objects rather than filenames, keeping scripts readable
• Incremental validation: SCons validates files and can fail gracefully at any step

Requirements

• Python 3.10+
• scons 3+

Installation

python3 -m pip install bioscons

Usage

Basic SCons pipeline:

from SCons.Script import Environment

env = Environment(MP_NUM_THREADS=3)

alignment = env.Command(
    target='$out/seqs.aln.fasta',
    source='$data/seqs.fasta',
    action='muscle -in $SOURCE -out $TARGET -threads 4'
)

tree = env.Command(
    target='$out/seqs.tre',
    source=alignment,
    action='FastTreeMP -nt -gtr $SOURCE > $TARGET'
)

Basic Bioscons pipeline using Slurm:

from bioscons.slurm import SlurmEnvironment

env = SlurmEnvironment(OMP_NUM_THREADS=3, use_cluster=True)

alignment = env.Command(
    target='$out/seqs.aln.fasta',
    source='$data/seqs.fasta',
    action='muscle -in $SOURCE -out $TARGET -threads 4',
    ncores=4
)

tree = env.Command(
    target='$out/seqs.tre',
    source=alignment,
    action='FastTreeMP -nt -gtr $SOURCE > $TARGET',
    ncores=3  # OMP_NUM_THREADS=3
)

See the full documentation for additional utilities.

Contributors

• Noah Hoffman
• Erick Matsen
• Chris Rosenthal
• Christopher Small
• Connor McCoy
• Tim Holland