Step 1: Wrap a loop with `progressbar`¶

A loop that takes a while to run gives no feedback while it works. This step wraps a plain for loop so it prints a live progress bar instead, without changing anything else about the loop.

"""Wrap an iterable to show its progress."""

import time

import progressbar

def main() -> None:
    for _ in progressbar.progressbar(range(100), fast=False):
        time.sleep(0.01)

if __name__ == '__main__':
    main()

Install the library first if you have not yet (Installation).

The example wraps range(100) in progressbar.progressbar(...) and iterates the result exactly as it would iterate range(100) on its own. progressbar.progressbar() is a function, not the bar itself: it takes an iterable, hands back an iterator over the same values, and starts, updates and finishes a bar behind the scenes as that iterator is consumed. There is no separate call to make the bar advance or to mark it done.

fast=False selects the widget renderer with its default colours. Without it, this simple loop uses the faster, uncoloured renderer.

That convenience comes from hiding the bar object entirely. The library also exposes it directly as the ProgressBar class, which you construct and update yourself when progress does not come from iterating something. The next step shows how.

Next: Step 2: Update a ProgressBar explicitly.

Step 1: Wrap a loop with progressbar¶

Step 1: Wrap a loop with `progressbar`¶