Installing pyjulia

Here is a little function that downloads julia if needed, set up an environmnt and instantiate the project.

I think something similar should be provided so that users can call it in setup.py

def setup_pyjulia_env(path_to_project="."):
    """
    A function that installs all dependencies for current environment.
    This should be the same as what `juliacall` does at every import time.
    * `path_to_project` is the path to the project that will be instantiated.
    If `None`, no project will be instantiated. Defaults: to the current
    working directory.
    """
    import jill.install  # noqa: autoimport
    import os  # noqa: autoimport
    import shutil  # noqa: autoimport
    if shutil.which('julia') is None:
        print(
            "No Julia executable found, installing the latest version using `jill`")
        jill.install.install_julia("stable", confirm=True)
        if shutil.which('julia') is None:
            print(f"Please add {os.environ['JILL_SYMLINK_DIR']} to your path")
    import julia  # noqa: autoimport
    # the following installs dependencies for pyjulia
    julia.install()
    from julia.api import LibJulia  # noqa: autoimport

    if path_to_project is not None:
        api = LibJulia.load()
        api.init_julia([f"--project={path_to_project}"])

        from julia import Main  # noqa: autoimport

        Main.eval('using Pkg')
        Main.eval('Pkg.instantiate()')

Example from: https://github.com/00sapo/pyjulia-vs-juliacall

[jlapeyre]

I neglected to mention here that I wrote a python package find_julia. It is lightweight and should be easy to use. It is a bit featureful, has more than you would want to put in pyjulia.

It supports specifying the required Julia version in exactly the same syntax and semantics that Julia does with julia_semver.

By default it prefers looking in the juliaup directory first and returns the best match. If there is no match, it looks in jill-installed locations. This is because the latter is a bit slower; juliaup caches the julia versions.

It offers to install, if none is found. This is done via jill.py, which is loaded on demand because it takes >50ms to load. In the future, supporting juliaup for downloading would be a good idea. I would do it now, but juliaup is still developing and it does not yet have an API.

[tkf]

Just to clarify: I think it’s very unlikely that I will merge or review a patch that maintains Julia installations in a Python-specific way. There should be a language-agnostic user-facing interface (like juliaup CLI).