Clearing a DOS terminal in a script

[Stephen_B]

This doesn't seem to work in a dos terminal at the start of a script:

from os import popen
print popen('clear').read()

Any idea why not? Thanks.

Stephen

[Chris Mellon]

On Dec 13, 2007 10:48 AM, Stephen_B <st*****@theboulets.netwrote:

This doesn't seem to work in a dos terminal at the start of a script:

from os import popen
print popen('clear').read()

Any idea why not? Thanks.

It opens "clear" with it's own virtual terminal and clears that
instead. There's an ANSI control code you can use to reset the screen,
try printing that.

[Stephen_B]

On Dec 13, 11:21 am, "Chris Mellon" <[e-mail]:

It opens "clear" with it's own virtual terminal and clears that
instead.

Even when I launch the script from a cmd shell with "python
myscript.py"?

There's an ANSI control code you can use to reset the screen, try printing that.

I googled "<Esc>[2J" as an ascii sequence that it is supposed to clear
the screen. How do I send that?

Stephen

[John Machin]

On Dec 14, 3:48 am, Stephen_B <[e-mail]:

This doesn't seem to work in a dos terminal at the start of a script:

from os import popen
print popen('clear').read()

Any idea why not? Thanks.

Maybe you are using a different "dos terminal". What is "clear"?

C:\junk>clear
'clear' is not recognized as an internal or external command,
operable program or batch file.

C:\junk>ver

Microsoft Windows XP [Version 5.1.2600]

C:\junk>help cls
Clears the screen.

CLS

C:\junk>

The following works for me:

<code>
import os
os.system('cls')
print 'Howzat?'
</code>

To use ANSI escape sequences with the "real" MS-DOS, one needed a
console device driver (ANSI.SYS was supplied) and had to invoke it in
the CONFIG.SYS file; presumably you can find out how to set this up in
a Windows Command Prompt window, but it doesn't seem to be worth the
bother if all you want to do is clear the window.

HTH,
John

[Chris Gonnerman]

Stephen_B wrote:

This doesn't seem to work in a dos terminal at the start of a script:

from os import popen
print popen('clear').read()

Any idea why not? Thanks.

As others have mentioned, you should just do:

os.system("cls")

Or, you can use my WConio module for fancier work.

http://newcenturycomputers.net/projects/wconio.html

Good luck!

-- Chris.

[Larry Bates]

Stephen_B wrote:

On Dec 13, 11:21 am, "Chris Mellon" <[e-mail]:

>It opens "clear" with it's own virtual terminal and clears that
instead.

Even when I launch the script from a cmd shell with "python
myscript.py"?

>There's an ANSI control code you can use to reset the screen, try printing that.

I googled "<Esc>[2J" as an ascii sequence that it is supposed to clear
the screen. How do I send that?

Stephen

Normally you would do:

import sys
sys.stdout.write(chr(27)+'[2J')
sys.stdout.flush()

Unfortunately that doesn't clear the screen because the ANSI module isn't loaded
by default. Use os.system('cls') as mentioned instead.

-Larry