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pyhmmer 0.10.14
ππ‘β¦οΈπ¦ PyHMMER
Cython bindings and Python interface to HMMER3.
πΊοΈ Overview
HMMER is a biological sequence analysis tool that uses profile hidden Markov
models to search for sequence homologs. HMMER3 is developed and maintained by
the Eddy/Rivas Laboratory at Harvard University.
pyhmmer is a Python package, implemented using the Cython
language, that provides bindings to HMMER3. It directly interacts with the
HMMER internals, which has the following advantages over CLI wrappers
(like hmmer-py):
single dependency: If your software or your analysis pipeline is
distributed as a Python package, you can add pyhmmer as a dependency to
your project, and stop worrying about the HMMER binaries being properly
setup on the end-user machine.
no intermediate files: Everything happens in memory, in Python objects
you have control on, making it easier to pass your inputs to HMMER without
needing to write them to a temporary file. Output retrieval is also done
in memory, via instances of the
pyhmmer.plan7.TopHits
class.
no input formatting: The Easel object model is exposed in the
pyhmmer.easel
module, and you have the possibility to build a
DigitalSequence
object yourself to pass to the HMMER pipeline. This is useful if your sequences are already
loaded in memory, for instance because you obtained them from another
Python library (such as Pyrodigal
or Biopython).
no output parsing: HMMER3 is notorious for its numerous output files
and its fixed-width tabular output, which is hard to parse (even
Bio.SearchIO.HmmerIO
is struggling on some sequences).
efficient: Using pyhmmer to launch hmmsearch on sequences
and HMMs in disk storage is typically as fast as directly using the
hmmsearch binary (see the Benchmarks section).
pyhmmer.hmmer.hmmsearch
uses a different parallelisation strategy compared to
the hmmsearch binary from HMMER, which can help getting the most of
multiple CPUs when annotating smaller sequence databases.
This library is still a work-in-progress, and in an experimental stage,
but it should already pack enough features to run biological analyses or
workflows involving hmmsearch, hmmscan, nhmmer, phmmer, hmmbuild
and hmmalign.
π§ Installing
pyhmmer can be installed from PyPI,
which hosts some pre-built CPython wheels for Linux and MacOS on x86-64 and Arm64, as well as the code required to compile from source with Cython:
$ pip install pyhmmer
Compilation for UNIX PowerPC is not tested in CI, but should work out of the
box. Note than non-UNIX operating systems (such as Windows) are not
supported by HMMER.
A Bioconda package is also available:
$ conda install -c bioconda pyhmmer
π Citation
PyHMMER is scientific software, with a
published paper
in the Bioinformatics. Please
cite both PyHMMER
and HMMER if you are using it in
an academic work, for instance as:
PyHMMER (Larralde et al., 2023), a Python library binding to HMMER (Eddy, 2011).
Detailed references are available on the Publications page of the
online documentation.
π Documentation
A complete API reference can
be found in the online documentation, or
directly from the command line using
pydoc:
$ pydoc pyhmmer.easel
$ pydoc pyhmmer.plan7
π‘ Example
Use pyhmmer to run hmmsearch to search for Type 2 PKS domains
(t2pks.hmm)
inside proteins extracted from the genome of Anaerococcus provencensis
(938293.PRJEB85.HG003687.faa).
This will produce an iterable over
TopHits that can be used for further sorting/querying in Python.
Processing happens in parallel using Python threads, and a TopHits
object is yielded for every HMM passed in the input iterable.
import pyhmmer
with pyhmmer.easel.SequenceFile("pyhmmer/tests/data/seqs/938293.PRJEB85.HG003687.faa", digital=True) as seq_file:
sequences = list(seq_file)
with pyhmmer.plan7.HMMFile("pyhmmer/tests/data/hmms/txt/t2pks.hmm") as hmm_file:
for hits in pyhmmer.hmmsearch(hmm_file, sequences, cpus=4):
print(f"HMM {hits.query_name.decode()} found {len(hits)} hits in the target sequences")
Have a look at more in-depth examples such as building a HMM from an alignment,
analysing the active site of a hit,
or fetching marker genes from a genome
in the Examples
page of the online documentation.
π Feedback
β οΈ Issue Tracker
Found a bug ? Have an enhancement request ? Head over to the GitHub issue
tracker if you need to report
or ask something. If you are filing in on a bug, please include as much
information as you can about the issue, and try to recreate the same bug
in a simple, easily reproducible situation.
ποΈ Contributing
Contributions are more than welcome! See CONTRIBUTING.md for more details.
β±οΈ Benchmarks
Benchmarks were run on a i7-10710U CPU running @1.10GHz with 6 physical / 12
logical cores, using a FASTA file containing 4,489 protein sequences extracted
from the genome of Escherichia coli
(562.PRJEB4685)
and the version 33.1 of the Pfam HMM library containing
18,259 domains. Commands were run 3 times on a warm SSD. Plain lines show
the times for pressed HMMs, and dashed-lines the times for HMMs in text format.
Raw numbers can be found in the benches folder.
They suggest that phmmer should be run with the number of logical cores,
while hmmsearch should be run with the number of physical cores (or less).
A possible explanation for this observation would be that HMMER
platform-specific code requires too many SIMD
registers per thread to benefit from simultaneous multi-threading.
To read more about how PyHMMER achieves better parallelism than HMMER for
many-to-many searches, have a look at the Performance page
of the documentation.
π See Also
Building a HMM from scratch? Then you may be interested in the pyfamsa
package, providing bindings to FAMSA,
a very fast multiple sequence aligner. In addition, you may want to trim alignments:
in that case, consider pytrimal, which
wraps trimAl 2.0.
If despite of all the advantages listed earlier, you would rather use HMMER
through its CLI, this package will not be of great help. You can instead check
the hmmer-py package developed
by Danilo Horta at the EMBL-EBI.
βοΈ License
This library is provided under the MIT License.
The HMMER3 and Easel code is available under the
BSD 3-clause license.
See vendor/hmmer/LICENSE and vendor/easel/LICENSE for more information.
This project is in no way affiliated, sponsored, or otherwise endorsed by
the original HMMER authors. It was developed by
Martin Larralde during his PhD project
at the European Molecular Biology Laboratory in
the Zeller team.
For personal and professional use. You cannot resell or redistribute these repositories in their original state.
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