This repository contains scripts to build Python wheels for the treelite project. Python wheels contain pre-compiled binaries, so that users no longer have to compile from the source. Thanks to Python wheels, one can install treelite by typing
pip install treeliteTo build a Python wheel, the following steps are carried out:
- Compile Protobuf library.
- Build the C++ library portion of treelite.
- Bundle the C++ library with Python files to build a Python wheel.
To build platform-specific wheels, this repo takes advantage of continuous integration platforms such as Travis CI and Appveyor. For now, it builds wheels for the following platforms:
- Windows (32-bit / 64-bit)
- Python 2.7
- Python 3.4, 3.5, 3.6
- Mac OS X (64-bit)
- Python 2.7
- Python 3.4, 3.5, 3.6
- Linux (32-bit / 64-bit)
- Python 2.7 with “narrow” Unicode (see “Notes on Unicode variations” below)
- Python 2.7 with “wide” Unicode (see “Notes on Unicode variations” below)
- Python 3.4, 3.5, 3.6
The completed wheels get stored to an S3 bucket, until the repository owner shall manually upload them to PyPI.
We are indebted to the trailblazing works of the multibuild project, which made cross-platform compilation much less painful. We also thank the maintainers of manylinux1 Docker image, without which it would be impractical to build widely compatible Linux binaries.
Unlike Mac OS X and Windows, Linux comes in many varieties, each distribution shipping with different versions of core system libraries. As a result, compiled Python extension modules built on one Linux distribution often do not work on other Linux distributions.
To enable portability among a wide range of Linux distributions, Python defines the manylinux1 platform tag, which mandates that Python wheel rely on a very small set of system libraries and only “old” versions of them. To produce such compatible wheels, we have to build them using CentOS 5, a very old distro. The build script uses the manylinux Docker image, which ships with CentOS 5 and multiple Python versions.
Python 2.x interpreters come in two variations, one compiled with “wide” Unicode and another with “narrow” Unicode. The wide Unicode build uses four bytes to store a Unicode letter internally, whereas the narrow build uses only two. No such distiction exists for Python 3.x.