Understanding Python Distributions¶
The PythonDistribution
Starlark type represents
a Python distribution, an entity providing a Python installation
and build files which PyOxidizer uses to build your applications. See
Python Distributions Provide Python for more.
Available Python Distributions¶
PyOxidizer ships with its own list of available Python distributions.
These are constructed via the
default_python_distribution()
Starlark function. Under
most circumstances, you’ll want to use one of these distributions
instead of providing your own because these distributions are tested
and should have maximum compatibility.
Here are the built-in Python distributions:
Source |
Version |
Flavor |
Build Target |
|
---|---|---|---|---|
CPython |
3.9.16 |
standalone_dynamic |
aarch64-unknown-linux-gnu |
|
CPython |
3.10.9 |
standalone_dynamic |
aarch64-unknown-linux-gnu |
|
CPython |
3.8.16 |
standalone_dynamic |
x86_64-unknown-linux-gnu |
|
CPython |
3.9.16 |
standalone_dynamic |
x86_64-unknown-linux-gnu |
|
CPython |
3.10.9 |
standalone_dynamic |
x86_64-unknown-linux-gnu |
|
CPython |
3.8.16 |
standalone_static |
x86_64-unknown-linux-musl |
|
CPython |
3.9.16 |
standalone_static |
x86_64-unknown-linux-musl |
|
CPython |
3.10.9 |
standalone_static |
x86_64-unknown-linux-musl |
|
CPython |
3.8.16 |
standalone_dynamic |
i686-pc-windows-msvc |
|
CPython |
3.9.16 |
standalone_dynamic |
i686-pc-windows-msvc |
|
CPython |
3.10.9 |
standalone_dynamic |
i686-pc-windows-msvc |
|
CPython |
3.8.16 |
standalone_static |
i686-pc-windows-msvc |
|
CPython |
3.9.16 |
standalone_static |
i686-pc-windows-msvc |
|
CPython |
3.10.9 |
standalone_static |
i686-pc-windows-msvc |
|
CPython |
3.8.16 |
standalone_dynamic |
x86_64-pc-windows-msvc |
|
CPython |
3.9.16 |
standalone_dynamic |
x86_64-pc-windows-msvc |
|
CPython |
3.10.9 |
standalone_dynamic |
x86_64-pc-windows-msvc |
|
CPython |
3.8.16 |
standalone_static |
x86_64-pc-windows-msvc |
|
CPython |
3.9.16 |
standalone_static |
x86_64-pc-windows-msvc |
|
CPython |
3.10.9 |
standalone_static |
x86_64-pc-windows-msvc |
|
CPython |
3.8.16 |
standalone_dynamic |
aarch64-apple-darwin |
|
CPython |
3.9.16 |
standalone_dynamic |
aarch64-apple-darwin |
|
CPython |
3.10.9 |
standalone_dynamic |
aarch64-apple-darwin |
|
CPython |
3.8.16 |
standalone_dynamic |
x86_64-apple-darwin |
|
CPython |
3.9.16 |
standalone_dynamic |
x86_64-apple-darwin |
|
CPython |
3.10.9 |
standalone_dynamic |
x86_64-apple-darwin |
All of these distributions are provided by the python-build-standalone, and are maintained by the maintainer of PyOxidizer.
Here is what those target triple values translate to:
aarch64-apple-darwin
64-bit ARM compiled for macOS.
i686-pc-windows-msvc
32-bit Windows using the Microsoft Visual C++ Compiler.
x86-64-pc-windows-msvc
64-bit Windows using the Microsoft Visual C++ Compiler.
x86_64-apple-darwin
64-bit Intel processors compiled for macOS.
x86_64-pc-unknown-linux-gnu
64-bit x86 (typically Intel or AMD) targeting Linux, with a dependency on GNU libc (glibc /
libc.so
).x86_64-pc-unknown-linux-musl
64-bit x86 (typically Intel or AMD) targeting Linux using musl libc. (Musl libc uses static linking for libc, unlike glibc.)
Python Version Compatibility¶
PyOxidizer is capable of working with Python 3.8, 3.9, and 3.10.
Python 3.10 is the default Python version because it has been around for a while and is relatively stable.
PyOxidizer’s tests are run primarily against the default Python version. So adopting a non-default version may risk running into subtle bugs.
Choosing a Python Distribution¶
The Python 3.10 distributions are the default and are better tested than the Python 3.8 and 3.9 distributions. 3.8 and 3.9 were the default in previous releases and are known to work.
The standalone_dynamic
distributions behave much more similarly
to traditional Python build configurations than do their
standalone_static
counterparts. The standalone_dynamic
distributions are capable of loading Python extension modules that
exist as shared library files. So when working with standalone_dynamic
distributions, Python wheels containing pre-built Python extension
modules often just work.
The downside to standalone_dynamic
distributions is that you cannot
produce a single file, statically-linked executable containing your
application in most circumstances: you will need a standalone_static
distribution to produce a single file executable.
But as soon as you encounter a third party extension module with a
standalone_static
distribution, you will need to recompile it. And
this is often unreliable.
Binary Portability of Distributions¶
The built-in Python distributions are built in such a way that they should run on nearly every system for the platform they target. This means:
All 3rd party shared libraries are part of the distribution (e.g.
libssl
andlibsqlite3
) and don’t need to be provided by the run-time environment.Some distributions are statically linked and have no dependencies on any external shared libraries.
On the glibc linked Linux distributions, they use an old glibc version for symbol versions, enabling them to run on Linux distributions created years ago. (The current version is 2.19, which was released in 2014.)
Any shared libraries not provided by the distribution are available in base operating system installs. On Linux, example shared libraries include
libc.so.6
andlinux-vdso.so.1
, which are part of the Linux Standard Base Core Configuration and should be present on all conforming Linux distros. On macOS, referenced dylibs includelibSystem
, which is part of the macOS core install.For Linux, see Distribution Considerations for Linux for portability considerations.
For macOS, see Distribution Considerations for macOS for portability considerations.
For Windows, see Distribution Considerations for Windows for portability considerations.
Known Issues with Distributions¶
There are various known issues with various distributions. The python-build-standalone project documentation at https://python-build-standalone.readthedocs.io/en/latest/ attempts to capture many of them.
PyOxidizer contains workaround for many of the limitations. For example,
PyOxidizer (specifically the pyembed
Rust crate) can automatically
configure the terminfo database at run-time.
The aarch64-apple-darwin
Python distributions are considered beta quality
because PyOxidizer does not have continuous CI coverage for this architecture.
Releases should be tested before they are released. But there may be
undetected breakage on unreleased commits on the main
branch due to
lack of CI coverage. This limitation should go away once GitHub Actions
supports running jobs on M1 hardware.