Install/Build from source¶

Note

The instructions here are for building python-flint from source. For most users it is recommended to install prebuilt binaries from PyPI or conda-forge instead. The instructions here are only needed if a binary is not available for the platform. See Install with pip or conda.

Simple build instructions¶

The simple explanation of how to build python-flint from source is that there are two steps:

Install FLINT >= 3.0 (see Installing the dependencies below).
Run pip install --no-binary python-flint python-flint.

For example on Ubuntu 24.04 (but not older versions of Ubuntu) and when installing python-flint >= 0.7.0 these two steps are:

sudo apt-get install libflint-dev
pip install --no-binary python-flint python-flint

The first command installs FLINT 3.0.1 system-wide. With the second command pip will download the source code for the latest release of python-flint from PyPI, build it and install it into the active Python environment. When building, pip will create a temporary isolated build environment and will install the Python build dependencies (Cython, meson, …) into this environment so it is not necessary to install them manually before running pip install.

If you have the source code locally then you can build and install with:

pip install path/to/python-flint-directory-or-archive

After installing from source it is recommended to run the tests to check that everything is working correctly as described in Testing your installation.

The remainder of this page provides more detailed instructions for:

Compatibility and supported versions.
Installing python-flint from source.
Installing older versions from source.
Installing the dependencies.
Installing from source on Windows.
Using FLINT from a non-standard location.
Installing in editable mode.

Note

If you have more than one Python environment in your system then you need to ensure that you are installing python-flint into the correct one. This may require using the full path to pip or something like python3 -m pip or you may need to activate the environment first.

Compatibility and supported versions¶

Note

The compatibility information here is mostly only relevant when building python-flint from source. For most users it is recommended to install pre-built binaries from PyPI or conda-forge. See Install with pip or conda.

Generally each release of python-flint will be compatible with a range of Python versions as described in SPEC 0. Since python-flint 0.5.0 the minimum supported FLINT version is 3.0 and each release of python-flint supports all versions of FLINT >= 3.0 available at the time of release.

Compatible versions (note that 0.7.0 is not yet released):

python-flint compatibility¶
python-flint	Release date	CPython	FLINT	Cython
0.7.0	Not yet	3.10-3.13	3.0-3.2?	3.0-3.1?
0.6.0	1st Feb 2024	3.9-3.12	3.0	3.0
0.5.0	22nd Oct 2023	3.9-3.12	3.0	3.0
0.4.0	8th Aug 2023	3.9-3.11	`2.9.0` (`Arb 2.23.0`)	3.0
0.3.0	7th Dec 2018	older Python versions	`< 3.0`	`< 3.0`

The minimum and maximum versions of Python represent the versions that are tested in CI and for which binaries are provided on PyPI. It is likely that python-flint will work with other versions of Python (particularly older Python versions) but this is not tested. It is possible that conda-forge may provide binaries for other versions of Python.

The minimum versions of Cython and FLINT are needed because it is known that python-flint will not even build with older versions of these libraries. The maximum versions of all dependencies are speculative and are based on the versions that are known to work at the time of release. It is possible that newer versions of Cython and FLINT will work but unlikely. During the year following the release of python-flint 0.4.0 every non-patch release of Cython, FLINT, or CPython has required changes to the python-flint source code to be able to build at all. In particular the following releases of Cython, FLINT and CPython had changes that would prevent building all versions of python-flint existing at the time:

Flint 3.0 (Arb and Flint merged, lots of changes)
Flint 3.1 (Function signature for fmpz_mod_mat changed)
Flint 3.2 (flint_randinit function name changed)
Cython 3.0 (Handling of dunders changed)
Cython 3.1 (Removal of PyInt_* functions)
CPython 3.12 (Removal of distutils)

It is expected then that any future untested 3.x version of Cython, FLINT, or CPython will not be compatible with past versions of python-flint which is why the table above lists the versions that were known to work at the time of release.

As of python-flint 0.7.0, CPython 3.13t free-threaded builds are tested in CI but wheels are not provided on PyPI. There are no known issues related to using python-flint in a PEP 703 free-threaded build but it is likely that mutating objects shared by multiple threads is not safe.

It is also possible to build and use python-flint for PyPy. Other Python implementations may work but are not tested.

Installing python-flint from source¶

Note

Also if you are working on python-flint itself then it is not recommended to install the package as described here. Instead see the Development workflow page for how to work on python-flint.

The source code for python-flint is available on GitHub and source distributions can be downloaded from PyPI.

To build from source you must first install the dependencies (see Installing the dependencies below for instructions). Once the dependencies are installed the following command will download the python-flint source code from PyPI, then build and install it into the active Python environment:

pip install python-flint

This will try to install a binary first but will otherwise download, build and install the latest release of python-flint from PyPI. If you definitely want to build from source then you can use the --no-binary option:

pip install --no-binary python-flint python-flint

To install a specific version of python-flint from PyPI use e.g.:

pip install python-flint==0.7.0a4

To build and install the latest python-flint from git master you can use:

pip install git+https://github.com/flintlib/python-flint.git@master

If you already have the source code downloaded or checked out from git, you can cd in and build and install with:

pip install .

Alternatively if you would like to build a wheel you can use pypa/build (first pip install build):

python -m build

Note that wheels built in this way will not include the dependencies (unlike those distributed on PyPI) and cannot generally be installed on other systems.

Since python-flint 0.7.0 the build system is meson and the build requirements and version constraints are listed in pyproject.toml. When using build isolation the build requirements are installed in a temporary virtual environment and so it should not be necessary to install them in the active Python environment before running pip install.

To build without build isolation with python-flint >= 0.7.0 the dependencies should first be installed in the active Python environment:

pip install Cython==3.0 meson meson-python ninja
pip install --no-build-isolation .

The meson build system will detect the versions of FLINT and Cython installed in the system and will fail if they are not versions that were known to be compatible at the time of the release of python-flint. To build against new, untested versions of FLINT or Cython you can pass the -Dflint_version_check=false option to the meson build system:

pip install --config-settings=setup-args="-Dflint_version_check=false" .

This is useful for testing new versions of FLINT with python-flint for example if you want to build python-flint against the latest git version of FLINT. See Compatibility and supported versions above for the versions of FLINT and Cython that are supported by each version of python-flint.

Installing older versions from source¶

For python-flint < 0.6.0 the source distribution did not include pyproject.toml and did not list the build requirements. Also for python-flint < 0.7.0 the build requirements were different and there were no version constraints listed on the dependencies. An list of the build requirements for older versions of python-flint is given above in Compatibility and supported versions.

For python-flint < 0.7.0 you will need to install the build requirements manually, pin the version of Cython, and disable build isolation:

pip install Cython==3.0 setuptools numpy
pip install --no-build-isolation .

For python-flint < 0.4.0 older versions of Cython are needed (<= 0.29). If the build fails during the Cython step then it is likely that a different version of Cython is needed.

Installing the dependencies¶

Note

It is not necessary to install the dependencies manually if you install from PyPI or conda-forge as is recommended. When installing with conda the packages for the dependencies will also be installed from conda-forge automatically. The binaries on PyPI are built with the dependencies bundled in the wheel so that they do not need to be installed separately.

The following instructions are only for when building python-flint from source if needed because a binary is not available for your platform. See Install with pip or conda.

The dependencies for building python-flint have changed over time. See Compatibility and supported versions above for the versions of the dependencies that are supported by each version of python-flint.

As of python-flint 0.7.0 the runtime dependencies are Python and FLINT (at least version 3.0) and the build-time dependencies are a C compiler, Cython, meson, meson-python and ninja. Commands shown above such as pip install . will install dependencies like Cython, meson etc automatically. If you already have Python and a C compiler then what needs to be installed before building python-flint is FLINT.

At the time of writing, few Linux distributions provide FLINT >= 3.0 in their package repositories but for example on Ubuntu 24.04 (but not any earlier Ubuntu versions) you can install FLINT 3.0.1 with:

sudo apt-get install libflint-dev

On MacOS you can install FLINT from homebrew with:

brew install flint

Other package managers may also provide FLINT but make sure that it is at least version 3.0.

Once FLINT is installed it should be possible to build python-flint with any of the commands shown above e.g.:

pip install .

If it is not possible to install FLINT from a package manager then you need to install GMP and MPFR and then build FLINT. You may still be able to install GMP and MPFR from a package manager for example on Ubuntu:

sudo apt-get install libgmp-dev libmpfr-dev

The python-flint git repo has a script bin/install_flint_ubuntu.sh that uses apt-get to install all dependencies needed to build FLINT, then builds FLINT from git using a specified git ref, and then installs FLINT system-wide:

bin/install_flint_ubuntu.sh v3.0.1  # version 3.0.1
bin/install_flint_ubuntu.sh main    # latest git

The script can be adapted for other Linux distributions or MacOS to use something other than apt-get to install dependencies.

If the whole stack needs to be built from source then download the source for all three (GMP, MPFR, FLINT) and build each with the standard:

./configure
make
make install

Adapt the configure commands as needed. Once these are installed you should again be able to install python-flint with:

pip install .

Installing from source on Windows¶

Note

Building from source is not the recommended way for most users to install python-flint, especially on Windows. For most users it is recommended to use the binaries from PyPI or conda-forge except in cases where a binary is not available for the platform. See Install with pip or conda.

The instructions in Installing the dependencies above are for Unix-like systems (e.g. Linux or MacOS). On Windows the dependencies can be built in a similar way using MSYS2 or under WSL. It is also possible to build python-flint and its dependencies using MSVC but we do not currently provide instructions for this. The conda-forge recipe for python-flint builds on Windows using MSVC.

The MSYS2 project provides a Unix-like environment for Windows and a package manager that can be used to install the dependencies. The git repo for python-flint has a script bin/cibw_before_all_windows.sh that installs the dependencies under MSYS2 and builds GMP, MPFR, FLINT. This script is used for building the Windows binaries for PyPI. We use the MinGW64 (mingw-w64-x86_64) toolchain for building on Windows rather than MSVC because it makes it possible to have a fat build of GMP (--enable-fat) which bundles micro-architecture specific optimisations for x86_64 in a redistributable shared library. This is important for performance on modern x86_64 CPUs and is not possible if building GMP with MSVC. Since we need to use MinGW64 for building GMP it is simplest to use it for building MPFR, FLINT and python-flint as well and means that the same Unix-style build scripts can be used for all platforms.

The python-flint project does not have much experience using MSVC. Possibly it would be better to build GMP using MinGW64 and then build MPFR, FLINT and python-flint using MSVC. It is also possible that it would be better to build GMP, MPFR, FLINT using MinGW64 and then build python-flint using MSVC. Someone with more experience with MSVC would need to help with this. We would welcome contributions that explain how to build python-flint and its dependencies using MSVC and/or that improve the build process for distributed binaries on Windows.

Using `FLINT` from a non-standard location¶

Note

This section is only relevant when building python-flint from source. For most users it is recommended to use the binaries from PyPI or conda-forge. See Install with pip or conda. The instructions here are also not needed if you have installed FLINT and its dependencies system-wide (e.g. using a package manager like apt-get or brew).

If you have installed FLINT in a non-standard location then you will need to instruct the python-flint build system where to find it and ensure that the FLINT shared library can be found at runtime.

Since python-flint 0.7.0 the build system is meson and uses pkg-config to find the dependencies FLINT, GMP and MPFR. If these are installed in a non-standard location then you can set the PKG_CONFIG_PATH environment variable to point to the directory containing the .pc files for these libraries. For example if you have installed FLINT in ~/.local then you can set the environment variable like this:

export PKG_CONFIG_PATH=$(pwd)/.local/lib/pkgconfig

Note that in some systems the lib/pkgconfig directory may be in a different location e.g. lib64/pkgconfig. It is also possible to pass the path to the pkg-config files to the meson-python build backend. For example if building with pip:

pip install \
    --config-settings=setup-args="--pkg-config-path=$(pwd)/.local/lib/pkgconfig" \
    python-flint

Setting the path to the pkg-config files in this way will allow the python-flint build system to find the FLINT library at build time. At runtime the GMP, MPFR and FLINT shared libraries must be in a location where the dynamic linker can find them. On Linux the environment variable LD_LIBRARY_PATH can be used to add the directory containing the shared libraries to the search path. On MacOS the environment variable is DYLD_LIBRARY_PATH and on Windows it is PATH. For example on Linux if FLINT is installed in ~/.local/lib then you can set the environment variable:

export LD_LIBRARY_PATH=$(pwd)/.local/lib

Using the environment variable like this means that it needs to be set every time you run Python and use python-flint (the git repo provides source bin/activate for doing this). A better option on Unix-like systems is to install RPATH entries into the python-flint extension modules. On some platforms this is done automatically by the meson build system but on others it needs to be enabled explicitly. This can be done by passing the -Dadd_flint_rpath=true option to the meson build system:

pip install \
    --config-settings=setup-args="--pkg-config-path=$(pwd)/.local/lib/pkgconfig" \
    --config-settings=setup-args="-Dadd_flint_rpath=true" \
    python-flint

For versions of python-flint before 0.7.0 the build system is setuptools (or numpy.distutils for Python < 3.12). In this case pkg-config is not used. The following environment variables can be used to set the location of the FLINT and other shared libraries at build time or runtime:

C_INCLUDE_PATH=$(pwd)/.local/include  # build-time
LIBRARY_PATH=$(pwd)/.local/lib        # build-time
LDFLAGS=-Wl,-rpath=$(pwd)/.local/lib  # build-time Linux or MacOS
LD_LIBRARY_PATH=$(pwd)/.local/lib     # run-time Linux
DYLD_LIBRARY_PATH=$(pwd)/.local/lib   # run-time MacOS
PATH=$(pwd)/.local/bin:$PATH          # run-time Windows

A future improvement for python-flint could be if the meson build system could build all dependencies (GMP, MPFR, FLINT) as shared libraries and bundle them into python-flint although this is not currently possible with meson-python. Otherwise perhaps it could be possible to link FLINT and the other libraries statically into python-flint.

Installing in editable mode¶

Note

For working on python-flint itself it is not recommended to install the package into the active Python environment. Instead the development workflow uses spin and meson to manage a local build of python-flint. See the Development workflow page for more information on how to develop python-flint.

If you are building and testing python-flint while working on another project then it may be useful to install python-flint in editable mode. This allows making changes to the code of python-flint and seeing the changes reflected in the other environment without needing to reinstall python-flint each time. This might be useful for example if you are using git bisect to find a change in python-flint (although it will not work if you go back to versions before 0.7.0).

Since 0.7.0 it is possible to install python-flint as a meson-python editable install. To install python-flint in editable mode, first install FLINT and then:

git clone https://github.com/flintlib/python-flint.git
cd python-flint
pip install meson meson-python cython ninja
pip install --no-build-isolation --editable .
python -m flint.test  # recommended if you have made changes

This requires --no-build-isolation so that the build directory is not deleted after install. Once installed in editable mode, each time Python is restarted and python-flint is imported (import flint) an import hook will check if the source code has changed and if so will rebuild the extension modules and update the Python files. The rebuild uses meson for fast, parallel, incremental rebuilds. Note that for the rebuild to happen and for the changes to take effect it is necessary to start a new Python process e.g. by running python again or by restarting the Jupyter kernel.

If you have installed FLINT in a non-standard location then you should set the pkg-config path as described in Using FLINT from a non-standard location above:

pip install
    --no-build-isolation \
    --config-settings=setup-args="--pkg-config-path=$(pwd)/.local/lib/pkgconfig" \
    --editable .

To fully remove the editable install you can run:

pip uninstall python-flint

and then delete the build directory that was created in the root of the python-flint git repo.

Install/Build from source¶

Simple build instructions¶

Compatibility and supported versions¶

Installing python-flint from source¶

Installing older versions from source¶

Installing the dependencies¶

Installing from source on Windows¶

Using FLINT from a non-standard location¶

Installing in editable mode¶

Using `FLINT` from a non-standard location¶