How to clear the interpreter console?

Question

Like most Python developers, I typically keep a console window open with the Python interpreter running to test commands, dir() stuff, help() stuff, etc.

Like any console, after a while the visible backlog of past commands and prints gets to be cluttered, and sometimes confusing when re-running the same command several times. I'm wondering if, and how, to clear the Python interpreter console.

I've heard about doing a system call and either calling cls on Windows or clear on Linux, but I was hoping there was something I could command the interpreter itself to do.

Note: I'm running on Windows, so Ctrl+L doesn't work.

Answer 1

Here's the definitive solution that merges all other answers. Features:

1. You can copy-paste the code into your shell or script.

2. You can use it as you like:

   >>> clear()
   >>> -clear
   >>> clear  # <- but this will only work on a shell
   

3. You can import it as a module:

   >>> from clear import clear
   >>> -clear
   

4. You can call it as a script:

   $ python clear.py
   

5. It is truly multiplatform; if it can't recognize your system
   (ce, nt, dos or posix) it will fall back to printing blank lines.

---

You can download the [full] file here: https://gist.github.com/3130325
Or if you are just looking for the code:

class clear:
 def __call__(self):
  import os
  if os.name==('ce','nt','dos'): os.system('cls')
  elif os.name=='posix': os.system('clear')
  else: print('\n'*120)
 def __neg__(self): self()
 def __repr__(self):
  self();return ''

clear=clear()

Answer 2

I'm using MINGW/BASH on Windows XP, SP3.

(stick this in .pythonstartup)
# My ctrl-l already kind of worked, but this might help someone else
# leaves prompt at bottom of the window though...
import readline
readline.parse_and_bind('\C-l: clear-screen')

# This works in BASH because I have it in .inputrc as well, but for some
# reason it gets dropped when I go into Python
readline.parse_and_bind('\C-y: kill-whole-line')

---

I couldn't stand typing 'exit()' anymore and was delighted with martineau's/Triptych's tricks:

I slightly doctored it though (stuck it in .pythonstartup)

class exxxit():
    """Shortcut for exit() function, use 'x' now"""
    quit_now = exit # original object
    def __repr__(self):
        self.quit_now() # call original
x = exxxit()

---

Py2.7.1>help(x)
Help on instance of exxxit in module __main__:

class exxxit
 |  Shortcut for exit() function, use 'x' now
 |
 |  Methods defined here:
 |
 |  __repr__(self)
 |
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |
 |  quit_now = Use exit() or Ctrl-Z plus Return to exit

Answer 3

EDIT: I've just read "windows", this is for linux users, sorry.

---

In bash:

#!/bin/bash

while [ "0" == "0" ]; do
    clear
    $@
    while [ "$input" == "" ]; do
        read -p "Do you want to quit? (y/n): " -n 1 -e input
        if [ "$input" == "y" ]; then
            exit 1
        elif [ "$input" == "n" ]; then
            echo "Ok, keep working ;)"
        fi
    done
    input=""
done

Save it as "whatyouwant.sh", chmod +x it then run:

./whatyouwant.sh python

or something other than python (idle, whatever). This will ask you if you actually want to exit, if not it rerun python (or the command you gave as parameter).

This will clear all, the screen and all the variables/object/anything you created/imported in python.

In python just type exit() when you want to exit.

Answer 4

This is the simplest thing you can do and it doesn't require any additional libraries. It will clear the screen and return >>> to the top left corner.

print("\033[H\033[J")

Answer 5

Magic strings are mentioned above - I believe they come from the terminfo database:

http://www.google.com/?q=x#q=terminfo

http://www.google.com/?q=x#q=tput+command+in+unix

$ tput clear| od -t x1z 0000000 1b 5b 48 1b 5b 32 4a >.[H.[2J< 0000007

Answer 6

Although this is an older question, I thought I'd contribute something summing up what I think were the best of the other answers and add a wrinkle of my own by suggesting that you put these command(s) into a file and set your PYTHONSTARTUP environment variable to point to it. Since I'm on Windows at the moment, it's slightly biased that way, but could easily be slanted some other direction.

Here's some articles I found that describe how to set environment variables on Windows:
    When to use sys.path.append and when modifying %PYTHONPATH% is enough
    How To Manage Environment Variables in Windows XP
    Configuring System and User Environment Variables
    How to Use Global System Environment Variables in Windows

BTW, don't put quotes around the path to the file even if it has spaces in it.

Anyway, here's my take on the code to put in (or add to your existing) Python startup script:

# ==== pythonstartup.py ====

# add something to clear the screen
class cls(object):
    def __repr__(self):
        import os
        os.system('cls' if os.name == 'nt' else 'clear')
        return ''

cls = cls()

# ==== end pythonstartup.py ====

BTW, you can also use @Triptych's __repr__ trick to change exit() into just exit (and ditto for its alias quit):

class exit(object):
    exit = exit # original object
    def __repr__(self):
        self.exit() # call original
        return ''

quit = exit = exit()

Lastly, here's something else that changes the primary interpreter prompt from >>> to cwd+>>>:

class Prompt:
    def __str__(self):
        import os
        return '%s >>> ' % os.getcwd()

import sys
sys.ps1 = Prompt()
del sys
del Prompt