How to refresh an stdout in python

Question

Hello and thank you in advance for your help, In fact I have a progress bar with various options that I would have liked to see refreshed instead of spending my time clearing the console.

while True :
    #system("cls")
    sys.stdout.write("\rSearching for {} --- [Currently {} found] \nLoading [".format(entry, count_result) + "="*int(100 * count / nb_files) + " "*(100-int(100 * count / nb_files)) + "] {}%".format(int(round(float(int(100 * count / nb_files))))) + "\n")
    sys.stdout.flush()
    sleep(0.5)
    if int(100 * count / nb_files) == 100 :
        sleep(1)
        system("cls")
        break

So I would have liked to know if there was a way, I looked everywhere to try to understand but I do not understand how I could do it in my case. thanks in advance

use this --> https://github.com/tqdm/tqdm instead of trying to build a progress bar — gold_cy, Dec 24 '21 at 19:19
Thank you but i don't want to use an external librairy. I want to understand how it works and do it with this style — Sénéchal Julien, Dec 24 '21 at 19:21

Yevhen Bondar · Accepted Answer · 2021-12-24T19:51:47.367

The easiest way to "refresh" progress bar is print line without LF (\n) a new symbol. Instead you you just CR (\r) carriage return symbol. With this approach cursor will return to the same line and rewrite it

import sys
import time

for i in range(100):
    print("Progress: {}% ".format(i), end="\r")
    time.sleep(.1)

The main downside of this approach, that it leaves symbols from the previous line. You can see it with this example.

import sys
import time

for i in range(100):
    print("Progress: {}% ".format(i), end="\r")
    time.sleep(.5)
    print("short line", end="\r")
    time.sleep(.5)

So, you should also clean line before you write a new one

import sys
import time

for i in range(100):    
    print("                                                                     ", end="\r")
    print("Progress: {}% ".format(i), end="\r")
    time.sleep(.1)

Here more info about CR and LF symbols What are carriage return, linefeed, and form feed?

The problem is that if I do this method on 2 lines: They will be deleted and appear alternately. Can't you get them both? — Sénéchal Julien, Dec 24 '21 at 22:24
Ok i found my answer (https://stackoverflow.com/questions/39455022/python-3-print-update-on-multiple-lines) ! Thx again — Sénéchal Julien, Dec 24 '21 at 22:43

How to refresh an stdout in python

1 Answers1