I have an wordtangler document saved as `ex1.py` under a folder I named `lpthw`, but I can't open it using a terminal.

I open the terminal and `cd` to the folder `lpthw`. Then, I write python `ex1.py`, but I get an error saying:

```
python: can't open file 'ex1.py': [Errno 2] No such file or directory

```

If I list the directory using `ls lpthw`, there is nothing.

Am I doing something wrong? Please help! Thank you!