Postfix¶

Postfix renders a live key-value mapping (or string) after the bar.

Reach for it to show a snapshot of several live values at once, like tqdm’s postfix, as one compact key=value, key=value suffix sourced from a bar variable.

class progressbar.widgets.Postfix(name='postfix', prefix=' ', separator=', ', **kwargs: Any)[source]

Bases: VariableMixin, WidgetBase

Displays a live postfix string or key-value mapping.

Create a Postfix.

Parameters:

name – data[‘variables’] key to read (see VariableMixin).
prefix – Prepended to the rendered value. Empty when the value itself is falsy (nothing to show).
separator – Joins key=value pairs when the variable holds a dict.
**kwargs – Forwarded to WidgetBase.__init__.

Example¶

"""``Postfix`` renders a live key-value mapping (or string) after the bar.

Reach for it to show a snapshot of several live values at once -- like
tqdm's postfix -- as one compact ``key=value, key=value`` suffix,
sourced from a bar variable. Compare ``Variable`` for a single formatted
value and ``FormatCustomText`` for text that is not tied to the bar's
variables at all.
"""

import random
import time

import progressbar

random.seed(0)

STEPS = 24


def main() -> None:
    widgets = [
        progressbar.Percentage(),
        ' ',
        progressbar.Bar(),
        progressbar.Postfix('stats'),
    ]
    with progressbar.ProgressBar(max_value=STEPS, widgets=widgets) as bar:
        for step in range(STEPS):
            stats = {
                'loss': round(random.random(), 3),
                'batch': step + 1,
            }
            bar.update(step + 1, stats=stats)
            time.sleep(0.005)


if __name__ == '__main__':
    main()

Postfix¶

Example¶

See also¶