listdir("/"): ['subdir'] listdir("."): ['subdir'] getcwd() in {"", "/"}: True chdir("subdir"): None getcwd(): /subdir mkdir("two"): None listdir("/"): ['subdir'] listdir("/subdir"): ['file.py', 'one', 'two'] listdir("."): ['file.py', 'one', 'two'] print('hello') hello chdir("/mnt/dir"): None getcwd(): /mnt/dir chdir("/mnt"): None getcwd(): /mnt chdir("/"): None getcwd(): / chdir("/mnt/dir"): None getcwd(): /mnt/dir chdir(".."): None getcwd(): /mnt False