Python的progressbar模块

The package can be installed through pip (this is the recommended method):

pip install progressbar2

Or if pip is not available, easy_install should work as well:

easy_install progressbar2

Or download the latest release from Pypi (https://pypi.python.org/pypi/progressbar2) or Github.

Note that the releases on Pypi are signed with my GPG key (https://pgp.mit.edu/pks/lookup?op=vindex&search=0xE81444E9CE1F695D) and can be checked using GPG:

gpg --verify progressbar2-<version>.tar.gz.asc progressbar2-<version>.tar.gz

Introduction

A text progress bar is typically used to display the progress of a long running operation, providing a visual cue that processing is underway.

The ProgressBar class manages the current progress, and the format of the line is given by a number of widgets. A widget is an object that may display differently depending on the state of the progress bar. There are many types of widgets:

• AbsoluteETA
• AdaptiveETA
• AdaptiveTransferSpeed
• AnimatedMarker
• Bar
• BouncingBar
• Counter
• CurrentTime
• DataSize
• DynamicMessage
• ETA
• FileTransferSpeed
• FormatCustomText
• FormatLabel
• Percentage
• ReverseBar
• RotatingMarker
• SimpleProgress
• Timer

The progressbar module is very easy to use, yet very powerful. It will also automatically enable features like auto-resizing when the system supports it.

Known issues

Due to limitations in both the IDLE shell and the Jetbrains (Pycharm) shells this progressbar cannot function properly within those.

• The IDLE editor doesn't support these types of progress bars at all: https://bugs.python.org/issue23220
• The Jetbrains (Pycharm) editors partially work but break with fast output. As a workaround make sure you only write to either sys.stdout (regular print) or sys.stderr at the same time. If you do plan to use both, make sure you wait about ~200 milliseconds for the next output or it will break regularly. Linked issue: https://github.com/WoLpH/python-progressbar/issues/115
• Jupyter notebooks buffer sys.stdout which can cause mixed output. This issue can be resolved easily using: import sys; sys.stdout.flush(). Linked issue: https://github.com/WoLpH/python-progressbar/issues/173

Links

• Documentation
  • https://progressbar-2.readthedocs.org/en/latest/
• Source
  • https://github.com/WoLpH/python-progressbar
• Bug reports
  • https://github.com/WoLpH/python-progressbar/issues
• Package homepage
  • https://pypi.python.org/pypi/progressbar2
• My blog
  • https://w.wol.ph/

Usage

There are many ways to use Python Progressbar, you can see a few basic examples here but there are many more in the examples file.

Wrapping an iterable

import time
import progressbar

for i in progressbar.progressbar(range(100)):
    time.sleep(0.02)

Progressbars with logging

Progressbars with logging require stderr redirection _before_ the StreamHandler is initialized. To make sure the stderr stream has been redirected on time make sure to call progressbar.streams.wrap_stderr() before you initialize the logger.

One option to force early initialization is by using the WRAP_STDERR environment variable, on Linux/Unix systems this can be done through:

# WRAP_STDERR=true python your_script.py

If you need to flush manually while wrapping, you can do so using:

import progressbar

progressbar.streams.flush()

In most cases the following will work as well, as long as you initialize the StreamHandler after the wrapping has taken place.

import time
import logging
import progressbar

progressbar.streams.wrap_stderr()
logging.basicConfig()

for i in progressbar.progressbar(range(10)):
    logging.error('Got %d', i)
    time.sleep(0.2)

Context wrapper

import time
import progressbar

with progressbar.ProgressBar(max_value=10) as bar:
    for i in range(10):
        time.sleep(0.1)
        bar.update(i)

Combining progressbars with print output

import time
import progressbar

for i in progressbar.progressbar(range(100), redirect_stdout=True):
    print('Some text', i)
    time.sleep(0.1)

Progressbar with unknown length

import time
import progressbar

bar = progressbar.ProgressBar(max_value=progressbar.UnknownLength)
for i in range(20):
    time.sleep(0.1)
    bar.update(i)

Bar with custom widgets

import time
import progressbar

widgets=[
    ' [', progressbar.Timer(), '] ',
    progressbar.Bar(),
    ' (', progressbar.ETA(), ') ',
]
for i in progressbar.progressbar(range(20), widgets=widgets):
    time.sleep(0.1)

Bar with wide Chinese (or other multibyte) characters

# vim: fileencoding=utf-8
import time
import progressbar


def custom_len(value):
    # These characters take up more space
    characters = {
        '进': 2,
        '度': 2,
    }

    total = 0
    for c in value:
        total += characters.get(c, 1)

    return total


bar = progressbar.ProgressBar(
    widgets=[
        '进度: ',
        progressbar.Bar(),
        ' ',
        progressbar.Counter(format='%(value)02d/%(max_value)d'),
    ],
    len_func=custom_len,
)
for i in bar(range(10)):
    time.sleep(0.1)