Multiline progress bars

Question

I know that to update something like a progress bar on the command line, one uses '\r'. Is there any way to update multiple lines?

Answer 1

If you're using Python try using blessings. It's a really intuitive wrapper around curses.

Simple example:

from blessings import Terminal
term = Terminal()
with term.location(0, 10):
 print("Text on line 10")
with term.location(0, 11):
 print("Text on line 11")

If you're actually trying to implement a progress bar, consider using progressbar. It will save you a lot of \r cruft.

You can actually connect blessings and progressbar together. Try running this:

import time
from blessings import Terminal
from progressbar import ProgressBar
term = Terminal()
class Writer(object):
 """Create an object with a write method that writes to a
 specific place on the screen, defined at instantiation.
 This is the glue between blessings and progressbar.
 """
 def __init__(self, location):
 """
 Input: location - tuple of ints (x, y), the position
 of the bar in the terminal
 """
 self.location = location
 def write(self, string):
 with term.location(*self.location):
 print(string)
writer1 = Writer((0, 10))
writer2 = Writer((0, 20))
pbar1 = ProgressBar(fd=writer1)
pbar2 = ProgressBar(fd=writer2)
pbar1.start()
pbar2.start()
for i in range(100):
 pbar1.update(i)
 pbar2.update(i)
 time.sleep(0.02)
pbar1.finish()
pbar2.finish()

multiline-progress

• lenz: This is perfect! Small update: the current version of progressbar wants the file handle to have a flush() method too.

Answer 2

The best way is to use some existing library like ncurses. But you may try dirty workaround by clearing console with system call: system("cls");.

• yodie: Is system("cls") Windows-only?
• mip: OS X core Darwin is Unix compliant and it should have "clear" along with other Unix-like systems.

Answer 3

You can use VT100 codes to reposition the cursor on a higher line, then overdraw it with your updated status.

• Sebastian: The link is broken. Here's web archive's version: web.archive.org/web/20110103061220/http://web.eecs.utk.edu/…

Answer 4

The Curses library offers powerful control for console UIs.