Open a text file using notepad as a help file in python?

os.startfile('file.txt')

From the python docs:

this acts like double clicking the file in Windows Explorer, or giving the file name as an argument to the start command from the interactive command shell: the file is opened with whatever application (if any) its extension is associated.

This way if your user changed their default text editor to, for example, notepad++ it would use their preference instead of notepad.

import webbrowser
webbrowser.open("file.txt")

Despite it's name it will open in Notepad, gedit and so on. Never tried it but it's said it works.

An alternative is to use

osCommandString = "notepad.exe file.txt"
os.system(osCommandString)

or as subprocess:

import subprocess as sp
programName = "notepad.exe"
fileName = "file.txt"
sp.Popen([programName, fileName])

but both these latter cases you will need to find the native text editor for the given operating system first.

You can do this in one line:

import subprocess
subprocess.call(['notepad.exe', 'file.txt'])

You can rename notepad.exe to the editor of your choice.

If you'd like to open the help file with the application currently associated with text files, which might not be notepad.exe, you can do it this way on Windows:

import subprocess
subprocess.call(['cmd.exe', '/c', 'file.txt'])