seqa-py 0.3.4

Python library for querying genomic files across cloud and local storage

seqa_py

Python library for querying genomic files (BAM, VCF, BED, BigWig, BigBed, FASTA, GFF, GTF) across local and cloud storage. Built on seqa_core via PyO3.

Installation

Requires uv and a Rust toolchain (rustup).

git clone <repo>
cd seqa_py
uv run maturin develop   # compile the Rust extension
uv sync --all-groups     # install runtime + dev dependencies (pytest, ruff, maturin)

After any change to src/lib.rs, re-run maturin develop.

Quick start

from seqa_py import file_search

lines = file_search("s3://my-bucket/sample.vcf.gz", "chr1:100000-200000")
for line in lines:
    print(line)

file_search

file_search(
    file_path: str,
    coordinates: str,
    include_header: bool = True,
    header_only: bool = False,
    genome: str | None = None,
) -> list[str]

Returns a list of tab-delimited result lines.

Parameter	Description
file_path	Local path or cloud URI (s3://, az://, gs://, https://)
coordinates	Genomic region — see formats below
include_header	Include file header lines in the result (default True)
header_only	Return only header lines, no data records (default False)
genome	Reference build for whole-chromosome length resolution: hg38, hg19, grch38, grch37

Coordinate formats

Input	Meaning
chr1:100000-200000	Range
chr1:100000	Single position
chr1:100,000-200,000	Commas ignored
chr1	Whole chromosome

Supported file types

Extension	Format
.bam	BAM (requires .bai index alongside)
.vcf.gz	VCF (requires .tbi index)
.bed.gz / .bed	BED (requires .tbi index)
.bedgraph.gz	BedGraph (requires .tbi)
.gff.gz	GFF3 (requires .tbi)
.gtf.gz	GTF (requires .tbi)
.bw / .bigwig	BigWig (self-indexed)
.bb / .bigbed	BigBed (self-indexed)
.fa / .fasta	FASTA (requires .fai index)

Index files must be at <file>.<ext> — e.g. sample.bam.bai, variants.vcf.gz.tbi. BigWig and BigBed embed their own index and need no companion file.

Errors

file_search raises ValueError for invalid paths, unsupported extensions, bad coordinates, or search failures.

---

Cloud credentials

Set environment variables before querying cloud files. A .env file in the working directory is loaded automatically.

AWS S3

AWS_ACCESS_KEY_ID=
AWS_SECRET_ACCESS_KEY=
AWS_REGION=
S3_BUCKET=

Azure Blob Storage

AZURE_TENANT_ID=
AZURE_CLIENT_ID=
AZURE_CLIENT_SECRET=
AZURE_STORAGE_ACCOUNT=
AZURE_STORAGE_CONTAINER=

Google Cloud Storage

GOOGLE_STORAGE_ACCOUNT=
GOOGLE_BUCKET=

Copy .env.example to .env and fill in the values.

---

Development

uv run maturin develop          # rebuild Rust extension
uv sync --all-groups            # restore dev dependencies (maturin develop resets the venv)
uv run pytest                   # all tests
uv run pytest tests/test_local.py -v    # local tests only (no cloud creds needed)
uv run ruff check .             # lint
uv run ruff format .            # format

Tests in tests/test_cloud.py are skipped automatically unless the relevant credentials are present in the environment.