This works on all platforms and it does work in both Python 2 and 3.
def clear(number):
for i in range(number):
print(" ")
Then to clear just type clear(numberhere).
So just thought I would throw my two cents in here...
No one has provided a true answer to OP question it seems, everyone either responds with 'NO DONT USE os.system() it's evil!!!' without explanation or provides a solution that relies on printing new lines.
For those that need to clear the terminal screen and scroll back, for whatever reason, you can use the following code:
import os
def clear():
'''
Clears the terminal screen and scroll back to present
the user with a nice clean, new screen. Useful for managing
menu screens in terminal applications.
'''
os.system('cls' if os.name == 'nt' else 'echo -e \\\\033c')
print('A bunch of garbage so we can garble up the screen...')
clear()
# Same effect, less characters...
def clear():
'''
Clears the terminal screen and scroll back to present
the user with a nice clean, new screen. Useful for managing
menu screens in terminal applications.
'''
os.system('cls||echo -e \\\\033c')
This has the OP's desired effect. It does use the os.system() command so if that's evil and someone knows a way of implementing this using subprocess.call() please comment as I would also prefer to use subprocess but am not familiar with it at all.
If you are on a Linux/UNIX system then printing the ANSI escape sequence to clear the screen should do the job. You will also want to move cursor to the top of the screen. This will work on any terminal that supports ANSI.
import sys
sys.stderr.write("\x1b[2J\x1b[H")
This will not work on Windows unless ANSI support has been enabled. There may be an equivalent control sequence for Windows, but I do not know.
You can use call() function to execute terminal's commands :
from subprocess import call
call("clear")
Just use:
print("\033c")
This will clear the terminal window.
This will clear 25 new lines:
def clear():
print(' \n' * 25)
clear()
I use eclipse with pydev. I like the newline solution better than the for num in range . The for loop throws warnings, while the print newline doesn't. If you want to specify the number of newlines in the clear statement try this variation.
def clear(j):
print(' \n' * j)
clear(25)
A simple and cross-platform solution would be to use either the cls command on Windows, or clear on Unix systems. Used with os.system, this makes a nice one-liner:
import os
os.system('cls' if os.name == 'nt' else 'clear')
For Windows, on the interpreter command line only (not the GUI)! Simply type: (Remember to use proper indentation with python):
import os
def clear():
os.system('cls')
Every time you type clear() on the shell (command line), it will clear the screen on your shell. If you exit the shell, then you must redo the above to do it again as you open a new Python (command line) shell.
Note: Does not matter what version of Python you are using, explicitly (2.5, 2.7, 3.3 & 3.4).
A perhaps cheesy way to clear the screen, but one that will work on any platform I know of, is as follows:
for i in xrange(0,100):
print ""
Why hasn't anyone talked about just simply doing Ctrl+L in Windows or Cmd+L in Mac. Surely the simplest way of clearing screen.
By default, os.system("clear")/os.system("cls") will return an int type as 0.
We can completely clear the screen by assigning it to a variable and deleting that.
def clear():
if (os.name == 'nt'):
c = os.system('cls')
else:
c = os.system('clear')
del c # can also omit c totally
#clear()
For Windows, Mac and Linux, you can use the following code:
import subprocess, platform
if platform.system()=="Windows":
subprocess.Popen("cls", shell=True).communicate() #I like to use this instead of subprocess.call since for multi-word commands you can just type it out, granted this is just cls and subprocess.call should work fine
else: #Linux and Mac
print("\033c", end="")
jamesnotjim tested print("\033c", end="") for Mac, and I tested it on Linux and Windows (it doesn't work for Windows, hence the other code that calls cls). I don't remember who it was I first saw use print("\033c") and/or the printf version: subprocess.Popen("printf '\033c'", shell=True).communicate().
rolika pointed out that end="" will prevent it from printing a new line afterward.
The accepted answer is a good solution. The problem with it is that so far it only works on Windows 10, Linux and Mac. Yes Windows (known for it lack of ANSI support)! This new feature was implemented on Windows 10 (and above) which includes ANSI support, although you have to enable it. This will clear the screen in a cross platform manner:
import os
print ('Hello World')
os.system('')
print ("\x1B[2J")
On anything below Windows 10 however it returns this:
[2J
This is due to the lack of ANSI support on previous Windows builds. This can however, be solved using the colorama module. This adds support for ANSI characters on Windows:
ANSI escape character sequences have long been used to produce colored terminal text and cursor positioning on Unix and Macs. Colorama makes this work on Windows, too, by wrapping stdout, stripping ANSI sequences it finds (which would appear as gobbledygook in the output), and converting them into the appropriate win32 calls to modify the state of the terminal. On other platforms, Colorama does nothing.
So here is a cross platform method:
import sys
if sys.platform == 'win32':
from colorama import init
init()
print('Hello World')
print("\x1B[2J")
Or print(chr(27) + "[2J") used instead of print("\x1B[2J").
@poke answer is very insecure on Windows, yes it works but it is really a hack. A file named cls.bat or cls.exe in the same dictionary as the script will conflict with the command and execute the file instead of the command, creating a huge security hazard.
One method to minimise the risk could be to change the location of where the cls command is called:
import os
os.system('cd C:\\Windows|cls' if os.name == 'nt' else 'clear')
This will change the Currant Dictionary to C:\Window (backslash is important here) then execute. C:\Windows is always present and needs administration permissions to write there making it a good for executing this command with minimal risk. Another solution is to run the command through PowerShell instead of Command Prompt since it has been secured against such vulnerabilities.
There are also other methods mentioned in this question: Clear screen in shell which may also be of use.
This function works in gnome-terminal because, by default, it recognizes ANSI escape sequences. It gives you a CLEAN PROMPT rows_max distance from the bottom of the terminal, but also precisely from where it was called. Gives you complete control over how much to clear.
def clear(rows=-1, rows_max=None, *, calling_line=True, absolute=None,
store_max=[]):
"""clear(rows=-1, rows_max=None)
clear(0, -1) # Restore auto-determining rows_max
clear(calling_line=False) # Don't clear calling line
clear(absolute=5) # Absolutely clear out to 5 rows up"""
from os import linesep
if rows_max and rows_max != -1:
store_max[:] = [rows_max, False]
elif not store_max or store_max[1] or rows_max == -1 or absolute:
try:
from shutil import get_terminal_size
columns_max, rows_max = get_terminal_size()
except ImportError:
columns_max, rows_max = 80, 24
if absolute is None:
store_max[:] = [rows_max, True]
if store_max:
if rows == -1:
rows = store_max[0]
elif isinstance(rows, float):
rows = round(store_max[0] * rows)
if rows > store_max[0] - 2:
rows = store_max[0] - 2
if absolute is None:
s = ('\033[1A' + ' ' * 30 if calling_line else '') + linesep * rows
else:
s = '\033[{}A'.format(absolute + 2) + linesep
if absolute > rows_max - 2:
absolute = rows_max - 2
s += (' ' * columns_max + linesep) * absolute + ' ' * columns_max
rows = absolute
print(s + '\033[{}A'.format(rows + 1))
Implementation:
clear() # Clear all, TRIES to automatically get terminal height
clear(800, 24) # Clear all, set 24 as terminal (max) height
clear(12) # Clear half of terminal below if 24 is its height
clear(1000) # Clear to terminal height - 2 (24 - 2)
clear(0.5) # float factor 0.0 - 1.0 of terminal height (0.5 * 24 = 12)
clear() # Clear to rows_max - 2 of user given rows_max (24 - 2)
clear(0, 14) # Clear line, reset rows_max to half of 24 (14-2)
clear(0) # Just clear the line
clear(0, -1) # Clear line, restore auto-determining rows_max
clear(calling_line=False) # Clear all, don't clear calling line
clear(absolute=5) # Absolutely clear out to 5 rows up
Parameters: rows is the number of clear text rows to add between prompt and bottom of terminal, pushing everything up. rows_max is the height of the terminal (or max clearing height) in text rows, and only needs to be set once, but can be reset at any time. *, in the third parameter position means all following parameters are keyword only (e.g., clear(absolute=5)). calling_line=True (default) works better in Interactive mode. calling_line=False works better for text-based, terminal applications. absolute was added to try to fix glitchy gap problems in Interactive mode after reducing size of terminal, but can also be used for terminal applications. store_max is just for secret, "persistent" storage of rows_max value; don't explicitly use this parameter. (When an argument is not passed for store_max, changing the list contents of store_max changes this parameter's default value. Hence, persistent storage.)
Portability: Sorry, this doesn't work in IDLE, but it works >> VERY COOL << in Interactive mode in a terminal (console) that recognizes ANSI escape sequences. I only tested this in Ubuntu 13.10 using Python 3.3 in gnome-terminal. So I can only assume portability is dependant upon Python 3.3 (for the shutil.get_terminal_size() function for BEST results) and ANSI recognition. The print(...) function is Python 3. I also tested this with a simple, text-based, terminal Tic Tac Toe game (application).
For use in Interactive mode: First copy and paste the copy(...) function in Interactive mode and see if it works for you. If so, then put the above function into a file named clear.py . In the terminal start python, with 'python3'. Enter:
>>> import sys
>>> sys.path
['', '/usr/lib/python3.3', ...
Now drop the clear.py file into one of the path directories listed so that Python can find it (don't overwrite any existing files). To easily use from now on:
>>> from clear import clear
>>> clear()
>>> print(clear.__doc__)
clear(rows=-1, rows_max=None)
clear(0, -1) # Restore auto-determining rows_max
clear(calling_line=False) # Don't clear calling line
clear(absolute=5) # Absolutely clear out to 5 rows up
For use in a terminal application: Put the copy(...) function into a file named clear.py in the same folder with your main.py file. Here is a working abstract (skeleton) example from a Tic Tac Toe game application (run from terminal prompt: python3 tictactoe.py):
from os import linesep
class TicTacToe:
def __init__(self):
# Clear screen, but not calling line
try:
from clear import clear
self.clear = clear
self.clear(calling_line=False)
except ImportError:
self.clear = False
self.rows = 0 # Track printed lines to clear
# ...
self.moves = [' '] * 9
def do_print(self, *text, end=linesep):
text = list(text)
for i, v in enumerate(text[:]):
text[i] = str(v)
text = ' '.join(text)
print(text, end=end)
self.rows += text.count(linesep) + 1
def show_board(self):
if self.clear and self.rows:
self.clear(absolute=self.rows)
self.rows = 0
self.do_print('Tic Tac Toe')
self.do_print(''' | |
{6} | {7} | {8}
| |
-----------
| |
{3} | {4} | {5}
| |
-----------
| |
{0} | {1} | {2}
| |'''.format(*self.moves))
def start(self):
self.show_board()
ok = input("Press <Enter> to continue...")
self.moves = ['O', 'X'] * 4 + ['O']
self.show_board()
ok = input("Press <Enter> to close.")
if __name__ == "__main__":
TicTacToe().start()
Explanation: do_print(...) on line 19 is a version of print(...) needed to keep track of how many new lines have been printed (self.rows). Otherwise, you would have to self.rows += 1 all over the place where print(...) is called throughout the entire program. So each time the board is redrawn by calling show_board() the previous board is cleared out and the new board is printed exactly where it should be. Notice self.clear(calling_line=False) on line 9 basically pushes everything up RELATIVE to the bottom of the terminal, but does not clear the original calling line. In contrast, self.clear(absolute=self.rows) on line 29 absolutely clears out everything self.rows distance upward, rather than just pushing everything upward relative to the bottom of the terminal.
Ubuntu users with Python 3.3: Put #!/usr/bin/env python3 on the very first line of the tictactoe.py file. Right click on the tictactoe.py file => Properties => Permissions tab => Check Execute: Allow executing file as program. Double click on the file => Click Run in Terminal button. If an open terminal's current directory is that of the tictactoe.py file, you can also start the file with ./tictactoe.py.
A Pure Python solution.
Does not rely on either ANSI, or external commands.
Only your terminal has to have the ability to tell you how many lines are in view.
from shutil import get_terminal_size
print("\n" * get_terminal_size().lines, end='')
Python version >= 3.3.0
If you wish to clear your terminal when you are using a python shell. Then, you can do the following to clear the screen
import os
os.system('clear')
If all you need is to clear the screen, this is probably good enough. The problem is there's not even a 100% cross platform way of doing this across linux versions. The problem is the implementations of the terminal all support slightly different things. I'm fairly sure that "clear" will work everywhere. But the more "complete" answer is to use the xterm control characters to move the cursor, but that requires xterm in and of itself.
Without knowing more of your problem, your solution seems good enough.
You could try to rely on clear but it might not be available on all Linux distributions. On windows use cls as you mentionned.
import subprocess
import platform
def clear():
subprocess.Popen( "cls" if platform.system() == "Windows" else "clear", shell=True)
clear()
Note: It could be considered bad form to take control of the terminal screen. Are you considering using an option? It would probably be better to let the user decide if he want to clear the screen.
You could tear through the terminfo database, but the functions for doing so are in curses anyway.
This will be work in Both version Python2 OR Python3
print (u"{}[2J{}[;H".format(chr(27), chr(27)))
As for me, the most elegant variant:
import os
os.system('cls||clear')
In Windows you can use:
>>> import os
>>> clear = lambda: os.system('cls')
>>> clear()
python -c "from os import system; system('clear')"
I would do it in this way to make it look more like bash:
Just create a file named .pythonstartup at Home directory and use poke's answer in a function
On Linux:
echo "from subprocess import call
def clear(int=None):
call('clear')
if int == 0:
exit()
clear()" >> $HOME/.pythonstartup ; export PYTHONSTARTUP=$HOME/.pythonstartup ; python
You can add export PYTHONSTARTUP=$HOME/.pythonstartup to your ./bashrc file
Since what I care about is space; a call to the function will not display the python interpreter description at startup, but you can remove clear() to retain it.
Using it like a normal function should do the trick without printing the exit status:
>>> clear()
If you pass the argument 0 to the function it will clear the screen and exit successfully so you can continue using the shell in a clean screen
>>> clear(0)
Came across this some time ago
def clearscreen(numlines=100):
"""Clear the console.
numlines is an optional argument used only as a fall-back.
"""
# Thanks to Steven D'Aprano, http://www.velocityreviews.com/forums
if os.name == "posix":
# Unix/Linux/MacOS/BSD/etc
os.system('clear')
elif os.name in ("nt", "dos", "ce"):
# DOS/Windows
os.system('CLS')
else:
# Fallback for other operating systems.
print('\n' * numlines)
Then just use clearscreen()
you can make your own. this will not be dependent on your terminal, or OS type.
def clear(num):
for i in range(num): print
clear(80)
print "hello"
Source: Stackoverflow.com