Implementing Dynamic Progress Bars in Python: Multiple Approaches and Code Examples

When writing Python scripts, especially for long‑running tasks or loops, showing a progress bar improves user experience and gives a clear view of the program's execution state.

1. Using the print function

import time

def progress_bar(n, total, bar_length=20):
    percent = float(n) / total
    arrow = '-' * int(round(percent * bar_length) - 1) + '>'
    spaces = ' ' * (bar_length - len(arrow))
    print(f'Progress: [{arrow}{spaces}] {int(round(percent * 100))}%', end='\r')

total = 50
for i in range(total):
    time.sleep(0.1)  # simulate work
    progress_bar(i + 1, total)
print()  # newline

Output example:

Progress: [--------------------->] 100%

2. Using the tqdm library

from tqdm import tqdm
import time

total = 50
for i in tqdm(range(total), desc="Processing"):
    time.sleep(0.1)  # simulate work

Output example:

Processing: 100%|██████████| 50/50 [00:05<00:00, 9.82it/s]

3. Custom style with tqdm

from tqdm import tqdm
import time

total = 50
for i in tqdm(range(total), desc="Processing", bar_format="{desc}: {n_fmt}/{total_fmt} [{elapsed}<{remaining}, {rate_fmt}{postfix}]"):
    time.sleep(0.1)  # simulate work

Output example:

Processing: 50/50 [00:05<00:00, 9.82it/s]

4. Multiple progress bars

from tqdm import tqdm
import time

with tqdm(total=100, desc="First") as pbar1, tqdm(total=100, desc="Second") as pbar2:
    for i in range(100):
        time.sleep(0.05)
        pbar1.update(1)
        pbar2.update(1)

Output example:

First: 100%|██████████| 100/100 [00:05<00:00, 19.31it/s]
Second: 100%|██████████| 100/100 [00:05<00:00, 19.31it/s]

5. Nested progress bars

from tqdm import tqdm
import time

outer = tqdm(total=100, desc="Outer Loop")
for i in outer:
    inner = tqdm(total=100, desc="Inner Loop", leave=False)
    for j in inner:
        time.sleep(0.01)
        inner.update(1)
    outer.update(1)
    inner.close()
outer.close()

Output example:

Outer Loop: 100%|██████████| 100/100 [00:10<00:00, 9.78it/s]

6. Controlling update frequency

from tqdm import tqdm
import time

total = 50
for i in tqdm(range(total), desc="Processing", mininterval=0.5):
    time.sleep(0.1)  # simulate work

Output example:

Processing: 100%|██████████| 50/50 [00:05<00:00, 9.82it/s]

7. Dynamic description

from tqdm import tqdm
import time

total = 50
with tqdm(total=total, desc="Starting") as pbar:
    for i in range(total):
        time.sleep(0.1)
        pbar.set_description(f"Processing {i+1}")
        pbar.update(1)

Output example:

Processing 50: 100%|██████████| 50/50 [00:05<00:00, 9.82it/s]

8. Custom callback function

from tqdm import tqdm
import time

def update_progress(progress):
    print(f"Progress: {progress}% completed.", end="\r")

total = 50
for i in range(total):
    time.sleep(0.1)
    update_progress(int((i + 1) / total * 100))
print()  # newline

Output example:

Progress: 100% completed.

9. Using the click library

import click
import time

total = 50
with click.progressbar(range(total), label='Processing') as bar:
    for i in bar:
        time.sleep(0.1)  # simulate work

Output example:

Processing 50/50 [100%]

10. Using the rich library

from rich.progress import track
import time

total = 50
for i in track(range(total), description="Processing..."):
    time.sleep(0.1)  # simulate work

Output example:

Processing... 100% 50/50 [00:05<00:00, 9.82it/s]

By reviewing these examples you can choose the most suitable method for displaying dynamic progress bars in your Python projects, depending on your specific requirements and environment.