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.

Asked By: Soviut

||

Answers:

Well, here’s a quick hack:

>>> clear = "n" * 100
>>> print clear
>>> ...do some other stuff...
>>> print clear

Or to save some typing, put this file in your python search path:

# wiper.py
class Wipe(object):
    def __repr__(self):
        return 'n'*1000

wipe = Wipe()

Then you can do this from the interpreter all you like 🙂

>>> from wiper import wipe
>>> wipe
>>> wipe
>>> wipe
Answered By: Kenan Banks

As you mentioned, you can do a system call:

For Windows:

>>> import os
>>> clear = lambda: os.system('cls')
>>> clear()

For Linux it would be:

>>> import os
>>> clear = lambda: os.system('clear')
>>> clear()
Answered By: Ryan Duffield

Use idle. It has many handy features. Ctrl+F6, for example, resets the console. Closing and opening the console are good ways to clear it.

Answered By: S.Lott

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


In bash:

#!/bin/bash

while true; do
    clear
    "[email protected]"
    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.

Answered By: Andrea Ambu

here something handy that is a little more cross-platform

import os

def cls():
    os.system('cls' if os.name=='nt' else 'clear')

# now, to clear the screen
cls()
Answered By: popcnt

Wiper is cool, good thing about it is I don’t have to type ‘()’ around it.
Here is slight variation to it

# wiper.py
import os
class Cls(object):
    def __repr__(self):
        os.system('cls')
        return ''

The usage is quite simple:

>>> cls = Cls()
>>> cls # this will clear console.
Answered By: Amol

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
Answered By: martineau

This should be cross platform, and also uses the preferred subprocess.call instead of os.system as per the os.system docs. Should work in Python >= 2.4.

import subprocess
import os

if os.name == 'nt':
    def clearscreen():
        subprocess.call("cls", shell=True)
        return
else:
    def clearscreen():
        subprocess.call("clear", shell=True)
        return
Answered By: Acorn

Here are two nice ways of doing that:

1.

import os

# Clear Windows command prompt.
if (os.name in ('ce', 'nt', 'dos')):
    os.system('cls')

# Clear the Linux terminal.
elif ('posix' in os.name):
    os.system('clear')

2.

import os

def clear():
    if os.name == 'posix':
        os.system('clear')

    elif os.name in ('ce', 'nt', 'dos'):
        os.system('cls')


clear()
Answered By: userend

How about this for a clear

- os.system('cls')

That is about as short as could be!

Answered By: Dennis Kean

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
Answered By: AAAfarmclub

The OS command clear in Linux and cls in Windows outputs a “magic string” which you can just print. To get the string, execute the command with popen and save it in a variable for later use:

from os import popen
with popen('clear') as f:
    clear = f.read()

print clear

On my machine the string is 'x1b[Hx1b[2J'.

Answered By: larsr
>>> ' '*80*25

UPDATE: 80×25 is unlikely to be the size of console windows, so to get the real console dimensions, use functions from pager module. Python doesn’t provide anything similar from core distribution.

>>> from pager import getheight
>>> 'n' * getheight()
Answered By: anatoly techtonik

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()
Answered By: Alba Mendez

I’m new to python (really really new) and in one of the books I’m reading to get acquainted with the language they teach how to create this little function to clear the console of the visible backlog and past commands and prints:

Open shell / Create new document / Create function as follows:

def clear():
    print('n' * 50)

Save it inside the lib folder in you python directory (mine is C:Python33Lib)
Next time you nedd to clear your console just call the function with:

clear()

that’s it.
PS: you can name you function anyway you want. Iv’ seen people using “wiper” “wipe” and variations.

Answered By: Adriana

OK, so this is a much less technical answer, but I’m using the Python plugin for Notepad++ and it turns out you can just clear the console manually by right-clicking on it and clicking “clear”. Hope this helps someone out there!

Answered By: guest12345

I found the simplest way is just to close the window and run a module/script to reopen the shell.

Answered By: Seymour

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
Answered By: tput-guest

just use this..

print 'n'*1000

Answered By: user1474157

I am using Spyder (Python 2.7) and to clean the interpreter console I use either

%clear

that forces the command line to go to the top and I will not see the previous old commands.

or I click “option” on the Console environment and select “Restart kernel” that removes everything.

Answered By: Youness

my way of doing this is to write a function like so:

import os
import subprocess

def clear():
    if os.name in ('nt','dos'):
        subprocess.call("cls")
    elif os.name in ('linux','osx','posix'):
        subprocess.call("clear")
    else:
        print("n") * 120

then call clear() to clear the screen.
this works on windows, osx, linux, bsd… all OSes.

Answered By: MartinUbuntu

I’m not sure if Windows’ “shell” supports this, but on Linux:

print "33[2J"

https://en.wikipedia.org/wiki/ANSI_escape_code#CSI_codes

In my opinion calling cls with os is a bad idea generally. Imagine if I manage to change the cls or clear command on your system, and you run your script as admin or root.

Answered By: Peter G. Marczis

If it is on mac, then a simple cmd + k should do the trick.

Answered By: CoderChai

Quickest and easiest way without a doubt is Ctrl+L.

This is the same for OS X on the terminal.

Answered By: Alex K

You have number of ways doing it on Windows:

1. Using Keyboard shortcut:

Press CTRL + L

2. Using system invoke method:

import os
cls = lambda: os.system('cls')
cls()

3. Using new line print 100 times:

cls = lambda: print('n'*100)
cls()
Answered By: Vlad Bezden

This is the simplest thing you can do and it doesn’t require any additional libraries. It clears the screen and returns >>> to the top left corner.

print("33[H33[J", end="")

UPDATE 1:

Since this answer gets some attention, you might want to know how it works. The command above prints ANSI escape codes:

  • 33 stands for ESC (ANSI value 27).

  • 33[ is a special escape sequence called Control Sequence
    Introducer
    (CSI).

  • 33[H command moves the cursor to the top left corner of the screen.

  • 33[J clears the screen from the cursor to the end of
    the screen.

Optional parameter end="" avoids printing newline character after executing these commands, so >>> stays in the topmost row.

UPDATE 2:

You may want to extend the above command with one additional parameter – x (before J):

print("33[H33[xJ", end="")
  • If x is 1, it will clear from cursor to beginning of the screen.
  • If x is 2, it will clear entire screen and move cursor to
    upper left.
  • If x is 3, it will clear entire
    screen and delete all lines saved in the scrollback buffer.

So, this command will clear everything, including buffer:

print("33[H33[3J", end="")

COMMAND LINE:

To clear screen in a shell (console / terminal) you can use the same command. To clear entire screen and delete all lines saved in the scrollback buffer put 3 before J:

printf "33[H33[3J"

or create an alias:

alias cls='printf "33[H33[3J"'
Answered By: Denis Rasulev

Here’s a cross platform (Windows / Linux / Mac / Probably others that you can add in the if check) version snippet I made combining information found in this question:

import os
clear = lambda: os.system('cls' if os.name=='nt' else 'clear')
clear()

Same idea but with a spoon of syntactic sugar:

import subprocess   
clear = lambda: subprocess.call('cls||clear', shell=True)
clear()
Answered By: Pitto

Arch Linux (tested in xfce4-terminal with Python 3):

# Clear or wipe console (terminal):
# Use: clear() or wipe()

import os

def clear():
    os.system('clear')

def wipe():
    os.system("clear && printf 'e[3J'")

… added to ~/.pythonrc

  • clear() clears screen
  • wipe() wipes entire terminal buffer
Answered By: Victoria Stuart

The perfect cls, also compatible with Python2 (in .pythonrc file):

from __future__ import print_function
cls = lambda: print("33c", end='')

and can be called from the terminal in this way:

cls()

Or directly:

print("33c", end='')

33[H33[J only clears the visible screen, exactly the same as the clear command up to Ubuntu 18.10. It doesn’t clear the scrollback buffer. Scrolling up will reveal the history.

To simulate this behavior, insert some terminal lines, then press Ctrl+L and insert more. After executing print("33[H33[J", end=""), only the screen lines inserted after pressing "Ctrl + L" will be deleted.

33c clears everything.

x1bc may not give the same result as 33c as the hex escape is not clearly length limited.

Answered By: Mario Palumbo

If you use vim keybindings in your .inputrc:

set editing-mode vi

It’s:

ESC Ctrl-L
Answered By: Spartan
Categories: questions Tags: , ,
Answers are sorted by their score. The answer accepted by the question owner as the best is marked with
at the top-right corner.