How to use the julia.core.which function in julia

import os
import shlex
import subprocess

import pytest

from julia.core import which
from julia.python_jl import parse_pyjl_args

is_windows = os.name == "nt"

PYJULIA_TEST_REBUILD = os.environ.get("PYJULIA_TEST_REBUILD", "no") == "yes"

python_jl_required = pytest.mark.skipif(
    os.environ.get("PYJULIA_TEST_PYTHON_JL_IS_INSTALLED", "no") != "yes"
    and not which("python-jl"),
    reason="python-jl command not found",
)


@pytest.mark.parametrize("args", [
    "-h",
    "-i --help",
    "--julia false -h",
    "--julia false -i --help",
])
def test_help_option(args, capsys):
    with pytest.raises(SystemExit) as exc_info:
        parse_pyjl_args(shlex.split(args))
    assert exc_info.value.code == 0

    captured = capsys.readouterr()

Check if Python `executable` is (likely to be) dynamically linked.

    It returns three possible values:

    * `True`: Likely that it's dynamically linked.
    * `False`: Likely that it's statically linked.
    * `None`: Unsupported platform.

    It's only "likely" since the check is by simple occurrence of a
    some substrings like "libpython".  For example, if there is
    another library existing on the path containing "libpython", this
    function may return false-positive.
    """
    path = which(executable)
    assert os.path.exists(path)
    if is_linux and which("ldd"):
        proc = run(
            ["ldd", path], stdout=subprocess.PIPE, env=_enviorn, universal_newlines=True
        )
        print_completed_proc(proc)
        return "libpython" in proc.stdout
    elif is_apple and which("otool"):
        proc = run(
            ["otool", "-L", path],
            stdout=subprocess.PIPE,
            env=_enviorn,
            universal_newlines=True,
        )
        print_completed_proc(proc)
        return (
            "libpython" in proc.stdout
            or "/Python" in proc.stdout

def is_dynamically_linked(executable):
    """
    Check if Python `executable` is (likely to be) dynamically linked.

    It returns three possible values:

    * `True`: Likely that it's dynamically linked.
    * `False`: Likely that it's statically linked.
    * `None`: Unsupported platform.

    It's only "likely" since the check is by simple occurrence of a
    some substrings like "libpython".  For example, if there is
    another library existing on the path containing "libpython", this
    function may return false-positive.
    """
    path = which(executable)
    assert os.path.exists(path)
    if is_linux and which("ldd"):
        proc = run(
            ["ldd", path], stdout=subprocess.PIPE, env=_enviorn, universal_newlines=True
        )
        print_completed_proc(proc)
        return "libpython" in proc.stdout
    elif is_apple and which("otool"):
        proc = run(
            ["otool", "-L", path],
            stdout=subprocess.PIPE,
            env=_enviorn,
            universal_newlines=True,
        )
        print_completed_proc(proc)
        return (

def test_incompatible_python(python, julia):

    if julia.eval("(VERSION.major, VERSION.minor)") == (0, 6):
        # Julia 0.6 implements mixed version
        return

    python = which(python)
    proc = runcode(
        python,
        """
        import os
        from julia import Julia
        Julia(runtime=os.getenv("PYJULIA_TEST_RUNTIME"), debug=True)
        """,
    )

    assert proc.returncode == 1
    assert "It seems your Julia and PyJulia setup are not supported." in proc.stderr
    dynamic = is_dynamically_linked(python)
    if dynamic is True:
        assert "`libpython` have to match" in proc.stderr
    elif dynamic is False:
        assert "is statically linked to libpython" in proc.stderr

* `None`: Unsupported platform.

    It's only "likely" since the check is by simple occurrence of a
    some substrings like "libpython".  For example, if there is
    another library existing on the path containing "libpython", this
    function may return false-positive.
    """
    path = which(executable)
    assert os.path.exists(path)
    if is_linux and which("ldd"):
        proc = run(
            ["ldd", path], stdout=subprocess.PIPE, env=_enviorn, universal_newlines=True
        )
        print_completed_proc(proc)
        return "libpython" in proc.stdout
    elif is_apple and which("otool"):
        proc = run(
            ["otool", "-L", path],
            stdout=subprocess.PIPE,
            env=_enviorn,
            universal_newlines=True,
        )
        print_completed_proc(proc)
        return (
            "libpython" in proc.stdout
            or "/Python" in proc.stdout
            or "/.Python" in proc.stdout
        )
    # TODO: support Windows
    return None