Problem with tkinter

[sylas]

Microsoft Windows [Version 10.0.16299.192]
© 2017 Microsoft Corporation. All rights reserved.

C:\Users\Sylvain>cd my_python_files

C:\Users\Sylvain\my_python_files>python helo.py

C:\Users\Sylvain\my_python_files>
At last I had to create :mkdir my_python_files. I did that as you see above.In Notepad I saved helo.py, because there are so many hello.py.
No success. Can you tell me how to see my files that are present in the folder my_python_files, since with windows "ls" is impossible.

---

There is a progress, now your file is named rep.py
Microsoft Windows [Version 10.0.16299.192]
© 2017 Microsoft Corporation. All rights reserved.

C:\Users\Sylvain>cd my_python_files

C:\Users\Sylvain\my_python_files>python rep.py
File "rep.py", line 2
class Application(tk.Frame):
^
IndentationError: unexpected indent

C:\Users\Sylvain\my_python_files>
Where can I look for repairing ? Thanks