I have this snippet of code that does not work. Well, it works fine, but it does not delete on my Windows computer. Please Help!

import time
import sys

def loading_bar(count, total, suffix=''):
    length = 60
    endlength = int(round(length * count / float(total)))

    percents = round(100.0 * count / float(total), 1)
    bar = '=' * endlength + '-' * (length - endlength)

    sys.stdout.write(f'[{bar}] {percents}% ...{suffix}\r')
    sys.stdout.flush()
    
def loading():
    items = list(range(0, 200))
    total_items = len(items)
    print("Loading:")
    for i, item in enumerate(items):
        time.sleep(0.1)
        loading_bar(i + 1, total_items, suffix=str(item))
    print()
    print("Done!")
    time.sleep(1)

loading()

I have this snippet of code that does not work. Well, it works fine, but it does not delete on my Windows computer. Please Help!

import time
import sys

def loading_bar(count, total, suffix=''):
    length = 60
    endlength = int(round(length * count / float(total)))

    percents = round(100.0 * count / float(total), 1)
    bar = '=' * endlength + '-' * (length - endlength)

    sys.stdout.write(f'[{bar}] {percents}% ...{suffix}\r')
    sys.stdout.flush()
    
def loading():
    items = list(range(0, 200))
    total_items = len(items)
    print("Loading:")
    for i, item in enumerate(items):
        time.sleep(0.1)
        loading_bar(i + 1, total_items, suffix=str(item))
    print()
    print("Done!")
    time.sleep(1)

loading()

• python
• sys

• 1 sys.stdout.flush() isn't responsible for deleting anything. The \r is what tells your terminal to send the cursor back to the beginning of the line it's already on; it's the terminal responsible for enacting that. The only thing flush() does is prevent buffering from delaying the write to the terminal, since usually stdout is line-buffered and isn't written until there's a newline (\n on UNIX, \r\n on Windows). – Charles Duffy Commented 2 days ago
• 2 So, first question here: Which terminal is your output being displayed in? Is this a windows cmd.exe window, or something built into an IDE or editor? – Charles Duffy Commented 2 days ago
• 1 it is on IDLE for windows, command prompt for iMac. – TH3KINGOFHYRULE Commented 2 days ago
• 1 Test at the command prompt on Windows. Probably it's not a Windows-vs-Mac difference but an IDLE-vs-terminal difference. – Charles Duffy Commented 2 days ago
• 2 It'll never work anywhere you don't have a terminal smart enough to honor \r, so I file this one under "don't use IDLE". (Microsoft's terminal isn't great, but this is something it should be okay for). – Charles Duffy Commented 2 days ago

1 Answer 1

IDLE doesn’t respond to \r the way a terminal should. You can run it at the command prompt with py yourscript.py or use an IDE that either has an integrated terminal (like VSCode) or one which has a shell that responds to \r and other ANSI terminal control codes (like Thonny). Otherwise your code is quite good.