HFST for python

CI/CD
Package
Meta

Package description

Package hfst contains python bindings for the Helsinki Finite-State Technology (HFST) C++ library. HFST toolkit is intended for processing natural language morphologies. The toolkit is demonstrated by wide-coverage implementations of a number of languages of varying morphological complexity.

Installation

For most users, simply run...

$ python3 -m pip install hfst

On some OSes, you can install hfst python bindings by running install_nightly.sh.

We compile wheels using cibuildwheel which enables us to publish wheels for CPython and PyPy on a large variety of OS/architecture combinations. If wheels for your platform are not available, open an issue! (Windows support coming soon!)

Usage

C++ side functions and classes are wrapped with SWIG under module 'libhfst'. It is possible to use this module directly, but there is a package named 'hfst' which encapsulates the libhfst module in a more user-friendly manner. The structure of the package is

• hfst
  • hfst.exceptions
  • hfst.sfst_rules
  • hfst.xerox_rules

The module hfst.exceptions contains HfstException and its subclasses. The modules hfst.sfst_rules and hfst.xerox_rules contain functions that create transducers implementing replace and two-level rules. All other functions and classes are in module hfst.

For documentation and examples, see https://hfst.github.io/python/index.html.

Requirements

Compiling hfst from source requires at least C++ compiler (tested with gcc 5.4.0), readline and getline libraries and setuptools package for python (tested with version 28.8.0). Swig is no longer needed as pre-generated files are included in source distribution.

Compiling from scratch

This repository has a submodule with the underlying C++ code. The first time you clone this repository, run $ git submodule init to initialize the submodule. Thereafter, every time that you want to pull in the latest changes from the C++ hfst repository, run $ git submodule update --remote or $ git pull --recurse-submodules. See the manylinux build script for an example of how to compile the underlying C++ library.

Once the library is available, the package can be installed by running...

python3 -m pip install .

...in the root directory of the repository.

Running tests

Tests are contained in the test/ directory. To run tests, you must first install pytest using python3 -m pip install pytest. Then, in the root directory of this repository, run python3 -m pytest.

Documentation

See wiki-based package documentation on our Github pages. In python, you can also use dir and help commands, e.g.:

dir(hfst)

help(hfst.HfstTransducer)

License

HFST is licensed under Gnu GPL version 3.0.

Troubleshooting

Pip starts to compile from source although there is a wheel available

Try upgrading pip with

python3 -m pip install --upgrade pip

Another reason for this can be that the source package on PyPI is newer (i.e. has a higher version number) than the corresponding wheel for the given environment. Report this via our issue tracker so a fresh wheel can be created.

Error message "command ... failed with error code ..."

Try rerunning pip in verbose mode with

python3 -m pip install --verbose [--upgrade] hfst

to get more information.

TypeError: catching classes that do not inherit from BaseException is not allowed

Some version combinations of SWIG and Python make HFST exception classes subclasses of Python's object instead of Exception. Then you will get the error above. If this is the case, run...

sed -i 's/class HfstException(_object):/class HfstException(Exception):/' libhfst.py

...after build/installation to be able to use HfstException and its subclasses in Python.

Links

HFST project main page: more information about the project

Github issue tracker: for comments, feature requests and bug reports

               GNU LESSER GENERAL PUBLIC LICENSE
                   Version 3, 29 June 2007

Copyright (C) 2007 Free Software Foundation, Inc. http://fsf.org/ Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.

This version of the GNU Lesser General Public License incorporates the terms and conditions of version 3 of the GNU General Public License, supplemented by the additional permissions listed below.

0. Additional Definitions.

As used herein, "this License" refers to version 3 of the GNU Lesser General Public License, and the "GNU GPL" refers to version 3 of the GNU General Public License.

"The Library" refers to a covered work governed by this License, other than an Application or a Combined Work as defined below.

An "Application" is any work that makes use of an interface provided by the Library, but which is not otherwise based on the Library. Defining a subclass of a class defined by the Library is deemed a mode of using an interface provided by the Library.

A "Combined Work" is a work produced by combining or linking an Application with the Library. The particular version of the Library with which the Combined Work was made is also called the "Linked Version".

The "Minimal Corresponding Source" for a Combined Work means the Corresponding Source for the Combined Work, excluding any source code for portions of the Combined Work that, considered in isolation, are based on the Application, and not on the Linked Version.

The "Corresponding Application Code" for a Combined Work means the object code and/or source code for the Application, including any data and utility programs needed for reproducing the Combined Work from the Application, but excluding the System Libraries of the Combined Work.

1. Exception to Section 3 of the GNU GPL.

You may convey a covered work under sections 3 and 4 of this License without being bound by section 3 of the GNU GPL.

2. Conveying Modified Versions.

If you modify a copy of the Library, and, in your modifications, a facility refers to a function or data to be supplied by an Application that uses the facility (other than as an argument passed when the facility is invoked), then you may convey a copy of the modified version:

a) under this License, provided that you make a good faith effort to ensure that, in the event an Application does not supply the function or data, the facility still operates, and performs whatever part of its purpose remains meaningful, or

b) under the GNU GPL, with none of the additional permissions of this License applicable to that copy.

3. Object Code Incorporating Material from Library Header Files.

The object code form of an Application may incorporate material from a header file that is part of the Library. You may convey such object code under terms of your choice, provided that, if the incorporated material is not limited to numerical parameters, data structure layouts and accessors, or small macros, inline functions and templates (ten or fewer lines in length), you do both of the following:

a) Give prominent notice with each copy of the object code that the Library is used in it and that the Library and its use are covered by this License.

b) Accompany the object code with a copy of the GNU GPL and this license document.

4. Combined Works.

You may convey a Combined Work under terms of your choice that, taken together, effectively do not restrict modification of the portions of the Library contained in the Combined Work and reverse engineering for debugging such modifications, if you also do each of the following:

a) Give prominent notice with each copy of the Combined Work that the Library is used in it and that the Library and its use are covered by this License.

b) Accompany the Combined Work with a copy of the GNU GPL and this license document.

c) For a Combined Work that displays copyright notices during execution, include the copyright notice for the Library among these notices, as well as a reference directing the user to the copies of the GNU GPL and this license document.

d) Do one of the following:

   0) Convey the Minimal Corresponding Source under the terms of this
   License, and the Corresponding Application Code in a form
   suitable for, and under terms that permit, the user to
   recombine or relink the Application with a modified version of
   the Linked Version to produce a modified Combined Work, in the
   manner specified by section 6 of the GNU GPL for conveying
   Corresponding Source.

   1) Use a suitable shared library mechanism for linking with the
   Library.  A suitable mechanism is one that (a) uses at run time
   a copy of the Library already present on the user's computer
   system, and (b) will operate properly with a modified version
   of the Library that is interface-compatible with the Linked
   Version.

e) Provide Installation Information, but only if you would otherwise be required to provide such information under section 6 of the GNU GPL, and only to the extent that such information is necessary to install and execute a modified version of the Combined Work produced by recombining or relinking the Application with a modified version of the Linked Version. (If you use option 4d0, the Installation Information must accompany the Minimal Corresponding Source and Corresponding Application Code. If you use option 4d1, you must provide the Installation Information in the manner specified by section 6 of the GNU GPL for conveying Corresponding Source.)

5. Combined Libraries.

You may place library facilities that are a work based on the Library side by side in a single library together with other library facilities that are not Applications and are not covered by this License, and convey such a combined library under terms of your choice, if you do both of the following:

a) Accompany the combined library with a copy of the same work based on the Library, uncombined with any other library facilities, conveyed under the terms of this License.

b) Give prominent notice with the combined library that part of it is a work based on the Library, and explaining where to find the accompanying uncombined form of the same work.

6. Revised Versions of the GNU Lesser General Public License.

The Free Software Foundation may publish revised and/or new versions of the GNU Lesser General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.

Each version is given a distinguishing version number. If the Library as you received it specifies that a certain numbered version of the GNU Lesser General Public License "or any later version" applies to it, you have the option of following the terms and conditions either of that published version or of any later version published by the Free Software Foundation. If the Library as you received it does not specify a version number of the GNU Lesser General Public License, you may choose any version of the GNU Lesser General Public License ever published by the Free Software Foundation.

If the Library as you received it specifies that a proxy can decide whether future versions of the GNU Lesser General Public License shall apply, that proxy's public statement of acceptance of any version is permanent authorization for you to choose that version for the Library.