How to configure os specific dependencies in a pyproject.toml file [Maturin]

Question

I have a rust and python project that I am building using Maturin(https://github.com/PyO3/maturin). It says that it requires a pyproject.toml file for the python dependencies.

I have a dependency of uvloop, which is not supported on windows and arm devices. I have added the code that conditionally imports these packages. However, I do not know how to conditionally install these packages. Right now, these packages are getting installed by default on every OS.

Here is the pyproject.toml file.

[project]
name = "robyn"
dependencies = [
  "watchdog>=2.1.3,<3",
  "uvloop>=0.16.0,<0.16.1",
  "multiprocess>=0.70.12.2,<0.70.12.3"
]

And the github link, jic anyone is interested: https://github.com/sansyrox/robyn/pull/94/files#diff-50c86b7ed8ac2cf95bd48334961bf0530cdc77b5a56f852c5c61b89d735fd711R21

See https://www.python.org/dev/peps/pep-0508/#environment-markers — wim, Nov 08 '21 at 21:46

score 5 · Answer 1 · answered Mar 12 '23 at 05:01

The syntax for environment markers is specified in PEP 508 – Dependency specification for Python Software Packages. I will show below how to exclude uvloop as a dependency on Windows platform with a marker for platform.system() which returns:

"Linux" on Linux
"Darwin" on macOS
"Windows" on Windows

Using `pyproject.toml`:

[project]
dependencies = [
    'uvloop ; platform_system != "Windows"',
]

Using `setup.cfg`:

[options]
install_requires =
    uvloop ; platform_system != "Windows"

Using `setup.py`:

setup(
    install_requires=[
        'uvloop ; platform_system != "Windows"',
    ]
)

score 0 · Answer 2 · answered Oct 14 '22 at 19:31

As wim indicated in their comment, https://peps.python.org/pep-0508/ specifies how to write constraints on package requirements.

In addition to restricting the package to a range of versions, you can restrict package installations based on various markers, such as sys_platform for the OS, separated from your other requirements with a semicolon.

I haven't tested this with pyproject.toml, but the following works in setup.cfg:

[options]
install_requires =
    uvloop ; sys_platform != "win32"

score -1 · Answer 3 · answered Dec 04 '21 at 15:35

-1

If you don't want to install on windows, specify like this:

# assuming you're using poetry
uvloop = {version = "^0.16.0", markers = 'sys_platform != "win32"'}

answered Dec 04 '21 at 15:35

kigawas

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so if there are 100 packages, i need to add markers to every package separately ? isn't there a way to define it gobally? – Antimatterr Mar 03 '23 at 05:56
You don't have to worry about it since most Python libraries are OS independent – kigawas Mar 10 '23 at 09:53
The question says they're using maturin, not poetry. – wim Mar 12 '23 at 04:46
@kigawas but there are libraries which are os specific ..exception are there always – Antimatterr Mar 18 '23 at 16:42

How to configure os specific dependencies in a pyproject.toml file [Maturin]

3 Answers3

Using pyproject.toml:

Using setup.cfg:

Using setup.py:

Using `pyproject.toml`:

Using `setup.cfg`:

Using `setup.py`: