Returns if a command matches an executable on the PATH

def is_executable(command):
    """Returns if a command matches an executable on the PATH"""

    paths = os.environ.get("PATH", "").split(os.path.pathsep)
    candidates = [command] + [os.path.join(p, command) for p in paths]
    return any(os.access(path, os.X_OK) for path in candidates)