Rewrite multiple lines in the console

On Unix, use the curses module.

On Windows, there are several options:

• PDCurses: http://www.lfd.uci.edu/~gohlke/pythonlibs/
• The HOWTO linked above recommends the Console module
• http://newcenturycomputers.net/projects/wconio.html
• http://docs.activestate.com/activepython/2.6/pywin32/win32console.html

Simple example using curses (I am a total curses n00b):

import curses
import time

def report_progress(filename, progress):
    """progress: 0-10"""
    stdscr.addstr(0, 0, "Moving file: {0}".format(filename))
    stdscr.addstr(1, 0, "Total progress: [{1:10}] {0}%".format(progress * 10, "#" * progress))
    stdscr.refresh()

if __name__ == "__main__":
    stdscr = curses.initscr()
    curses.noecho()
    curses.cbreak()

    try:
        for i in range(10):
            report_progress("file_{0}.txt".format(i), i+1)
            time.sleep(0.5)
    finally:
        curses.echo()
        curses.nocbreak()
        curses.endwin()

Like this:

#!/usr/bin/env python

import sys
import time
from collections import deque

queue = deque([], 3)
for t in range(20):
    time.sleep(0.5)
    s = "update %d" % t
    for _ in range(len(queue)):
        sys.stdout.write("\x1b[1A\x1b[2K") # move up cursor and delete whole line
    queue.append(s)
    for i in range(len(queue)):
        sys.stdout.write(queue[i] + "\n") # reprint the lines

I discovered this in the Jiri project, written in Go.

Even better: erase all lines after done:

#!/usr/bin/env python

import sys
import time
from collections import deque

queue = deque([], 3)
t = 0
while True:
    time.sleep(0.5)
    if t <= 20:
        s = "update %d" % t
        t += 1
    else:
        s = None
    for _ in range(len(queue)):
        sys.stdout.write("\x1b[1A\x1b[2K") # move up cursor and delete whole line
    if s != None:
        queue.append(s)
    else:
        queue.popleft()
    if len(queue) == 0:
        break
    for i in range(len(queue)):
        sys.stdout.write(queue[i] + "\n") # reprint the lines