def lookPath(executable):
    for path_dir in os.environ['PATH'].split(os.pathsep):
        executable_path = os.path.join(path_dir, executable)
        if os.path.exists(executable_path):
            return executable_path
    return ''
def lookPath(executable):
    for path_dir in os.environ['PATH'].split(os.pathsep):
        executable_path = os.path.join(path_dir, executable)
        if os.path.exists(executable_path):
            return executable_path
    return 