Printing on the same line on a jupyter notebook

Question

In python 3, we can easily print on the same line using the following script. I use this to understand the progress of my loop (how much time will be left). However, in jupy

Answer 1

The part "\r" overwrites the line, if you leave that you append to the line. Your version print(f, end='', flush=False) could work but I've read under Python 3 you need to use sys.stdout.write() and best is if you add flush command too.

import sys
import time

for f in range(10):
    #delete "\r" to append instead of overwrite
    sys.stdout.write("\r" + str(f))
    sys.stdout.flush()
    time.sleep(10)

The stdout.flush is required on some systems or you won't get any output

Answer 2

Found the solution to this a bit later (note that it does not work in pycharm jupyter, but only in the browser implementation). For me print works fine, but here display is advised, but it prints apostrophes around strings.

from time import sleep
from IPython.display import clear_output, display

for f in range(10):
    clear_output(wait=True)
    print(f)  # use display(f) if you encounter performance issues
    sleep(10)

Edit: Just wanted to add that TQDM is often also a good tool for this goal. It displays progress bars and allows you to write output below it or differ the description of each bar. See also this post.

import sys
from tqdm import tqdm
from time import sleep

values = range(3)
with tqdm(total=len(values), file=sys.stdout) as pbar:
    for i in values:
        pbar.set_description('processed: %d' % (1 + i))
        pbar.update(1)
        sleep(1)

And the notebook one with nice colours

from tqdm import tqdm, tqdm_notebook
from time import sleep

for i in tqdm_notebook(range(2), desc='1st loop'):
    sleep(0.01)
    tqdm.write(f"Done task {i}")

Answer 3

Prefix a \r and add an argument end="" to print, like so

print("\rThis will be printed on the same line", end="")

This works in the Jupyter notebook in Google Colab.