How to exit Python script in Command Prompt?

You could simply type "quit()" and its done!
CTRL + C will interrupt a running script; but you only want to quit the interpreter. So quit() function will work for you.

For an embedded python (e.g. python-3.6.8-embed-win32) quit() command does not work

Python 3.6.8 (tags/v3.6.8:3c6b436a57, Dec 23 2018, 23:31:17) [MSC v.1916 32 bit (Intel)] on win32
>>> quit()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'quit' is not defined

The only way that works is: CTRL + Z then Return.

ctrl+Z works still

..\AppData\Local\Programs\Python\Python37>python
Python 3.7.2 (tags/v3.7.2:9a3ffc0492, Dec 23 2018, 22:20:52) [MSC v.1916 32 bit (Intel)] on win32
>>>
>>> (1+4)*2
10
>>> ^Z

It indeed depends on the OS, and probably on the version of Python you are using.

As you mentioned, ctrl+C does not work on your Windows 10 with Python 3.6, but it does work on my Windows 10 with Python 3.4. Therefore, you really need to try and see what works for you.

Try the following commands, and keep the one that works:

• ctrl+C
• ctrl+D
• ctrl+Z then Return

In addition, the following should work with any terminal:

• exit() then Return
• quit() then Return

Trivia: if you type quit and hit Return, the console tells you, at least for Python 3.4:

Use quit() or Ctrl-Z plus Return to exit