NCBItax2lin

Convert NCBI taxonomy dump into lineages. An example for human (tax_id=9606) is like

tax_id	superkingdom	phylum	class	order	family	genus	species	family1	forma	genus1	infraclass	infraorder	kingdom	no rank	no rank1	no rank10	no rank11	no rank12	no rank13	no rank14	no rank15	no rank16	no rank17	no rank18	no rank19	no rank2	no rank20	no rank21	no rank22	no rank3	no rank4	no rank5	no rank6	no rank7	no rank8	no rank9	parvorder	species group	species subgroup	species1	subclass	subfamily	subgenus	subkingdom	suborder	subphylum	subspecies	subtribe	superclass	superfamily	superorder	superorder1	superphylum	tribe	varietas
9606	Eukaryota	Chordata	Mammalia	Primates	Hominidae	Homo	Homo sapiens					Simiiformes	Metazoa	cellular organisms	Opisthokonta	Dipnotetrapodomorpha	Tetrapoda	Amniota	Theria	Eutheria	Boreoeutheria					Eumetazoa				Bilateria	Deuterostomia	Vertebrata	Gnathostomata	Teleostomi	Euteleostomi	Sarcopterygii	Catarrhini					Homininae			Haplorrhini	Craniata				Hominoidea	Euarchontoglires

Install

ncbitax2lin supports python-3.9 to python-3.13.

pip install -U ncbitax2lin

It is also available in Conda on the Bioconda channel:

conda install bioconda::ncbitax2lin

Generate lineages

First download taxonomy dump from NCBI:

wget -N ftp://ftp.ncbi.nlm.nih.gov/pub/taxonomy/taxdump.tar.gz
mkdir -p taxdump && tar zxf taxdump.tar.gz -C ./taxdump

Then, run ncbitax2lin

ncbitax2lin --nodes-file taxdump/nodes.dmp --names-file taxdump/names.dmp

By default, the generated lineages will be saved to ncbi_lineages_[date_of_utcnow].csv.gz. The output file can be overwritten with --output option.

FAQ

Q: I have a large number of sequences with their corresponding accession numbers from NCBI, how to get their lineages?

A: First, you need to map accession numbers (GI is deprecated) to tax IDs based on nucl_*accession2taxid.gz files from ftp://ftp.ncbi.nih.gov/pub/taxonomy/accession2taxid/. Secondly, you can trace a sequence’s whole lineage based on its tax ID. The tax-id-to-lineage mapping is what NCBItax2lin can generate for you.

If you have any question about this project, please feel free to create a new issue.

Note on taxdump.tar.gz.md5

It appears that NCBI periodically regenerates taxdump.tar.gz and taxdump.tar.gz.md5 even when its content is still the same. I am not sure how their regeneration works, but taxdump.tar.gz.md5 will differ simply because of a different timestamp.

Used in

• Mahmoudabadi, G., & Phillips, R. (2018). A comprehensive and quantitative exploration of thousands of viral genomes. ELife, 7. https://doi.org/10.7554/eLife.31955
• Dombrowski, N. et al. (2020) Undinarchaeota illuminate DPANN phylogeny and the impact of gene transfer on archaeal evolution, Nature Communications. Springer US, 11(1). doi: 10.1038/s41467-020-17408-w. https://www.nature.com/articles/s41467-020-17408-w
• Schenberger Santos, A. R. et al. (2020) NAD+ biosynthesis in bacteria is controlled by global carbon/ nitrogen levels via PII signaling, Journal of Biological Chemistry, 295(18), pp. 6165–6176. doi: 10.1074/jbc.RA120.012793. https://www.sciencedirect.com/science/article/pii/S0021925817482433
• Villada, J. C., Duran, M. F. and Lee, P. K. H. (2020) Interplay between Position-Dependent Codon Usage Bias and Hydrogen Bonding at the 5’ End of ORFeomes, mSystems, 5(4), pp. 1–18. doi: 10.1128/msystems.00613-20. https://msystems.asm.org/content/5/4/e00613-20
• Byadgi, O. et al. (2020) Transcriptome analysis of amyloodinium ocellatum tomonts revealed basic information on the major potential virulence factors, Genes, 11(11), pp. 1–12. doi: 10.3390/genes11111252. https://www.mdpi.com/2073-4425/11/11/1252
• Cumbo, F., & Blankenberg, D. (2025). Characterization of microbial dark matter at scale with MetaSBT and taxonomy-aware Sequence Bloom Trees. bioRxiv. https://doi.org/10.1101/2025.08.25.672238

Development

Install dependencies

poetry install --sync

Testing

make format
make all

Publish (only for administrator)

poetry version [minor/major etc.]
git tag vx.y.z
git push origin vx.y.z
poetry publish --build -u __token__ --password pypi-<token-from-pypi>

Update CHANGELOG.md.