OpenFst-Python exposes the official Python API to OpenFst (officially called pywrapfst), but includes all the required OpenFst libraries in the Python package, so you don't need to install it separately.
The version number of OpenFst-Python is the same as the OpenFst version used. The current version uses OpenFst 1.8.2.
The build process will download and build OpenFst from the official webpage, so you need an Internet connection and all OpenFst dependencies. Essentially, you will need:
- A C++ compiler supporting C++17 (tested with GCC 12 on Debian 12 which python version >= 3.10).
- Cython.
- PatchELF.
- Zlib development.
- Python Requests.
Most likely, you need to install deps. Then, simply install the package from PyPI:
pip install absl-py requests cython==0.29.36After that installing from sources, you can simply do:
python setup.py installNotice that this downloads the appropriate version of OpenFst directly from the Internet. If you don't have an Internet connection but are already in possession of the appropriate tar.gz file, you can use the following command:
python setup.py build --download-dir=DIRECTORY_CONTAINING_OPENFST_TAR_GZ
python setup.py installpython openfst_python/test.pyThe Python API is the official one provided by OpenFst. Please, refer to its documentation.
A toy example:
import openfst_python as fst
f = fst.VectorFst()
s0 = f.add_state()
s1 = f.add_state()
s2 = f.add_state()
f.add_arc(s0, fst.Arc(1, 2, fst.Weight(f.weight_type(), 3.0), s1))
f.add_arc(s0, fst.Arc(1, 3, fst.Weight.one(f.weight_type()), s2))
f.add_arc(s1, fst.Arc(2, 1, fst.Weight(f.weight_type(), 1.0), s2))
f.set_start(s0)
f.set_final(s2, fst.Weight(f.weight_type(), 1.5))The OpenFst library is licensed under the Apache License, Version 2.0.
OpenFst-Python is just a wrapper of its official Python API, so
I am using the same license for most of the source code.
ac_python_devel.m4 was not written by me and it is licensed under the
GPL license.