which() is a Python method that returns the full path of a (shell) command.

python_which.py

#!/usr/bin/env python
# Author: James Cherti
# License: MIT
# URL: https://gist.github.com/jamescherti/53e5d3bb4da597f24f4fe8c42fe49ea1
"""Which() is a Python method that returns the full path of a (shell) command."""

from pathlib import Path
import os

def which(command: str) -> Path:
    """Return the full path of a (shell) command."""
    if os.path.isfile(command) and os.access(command, os.X_OK):
        return Path(command)

    try:
        path_dirs = [Path(item.strip())
                     for item in os.environ["PATH"].split(os.pathsep)]
    except KeyError:
        path_dirs = []

    for path in path_dirs:
        cmd_path = path.joinpath(command)
        if os.access(str(cmd_path), os.X_OK):
            return cmd_path

    raise FileNotFoundError("the command '{}' wasn't found."
                            .format(command))