How do I open Python IDLE (Shell WIndow) in WIndows 10?

Start menu > type IDLE (Python 3.4.3 <bitnum>-bit).

Replace <bitnum> with 32 if 32-bit, otherwise 64.

Example:

IDLE (Python 3.6.2 64-bit)

I agree with one who says:

just type "IDLE" in the start-menu where it says "Type here to search" and press [{ENTER}]

In Windows you will need to right click a .py, and press Edit to edit the file using IDLE. Since the default action of double clicking a .py is executing the file with python on a shell prompt.

To open just IDLE:

Click on that. C:\Python36\Lib\idlelib\idle.bat