详解Python中如何写控制台进度条的整理


Posted in Python onMarch 07, 2018

本文实例讲述了Python显示进度条的方法,是Python程序设计中非常实用的技巧。分享给大家供大家参考。具体方法如下:

首先,进度条和一般的print区别在哪里呢?

答案就是print会输出一个\n,也就是换行符,这样光标移动到了下一行行首,接着输出,之前已经通过stdout输出的东西依旧保留,而且保证我们在下面看到最新的输出结果。

进度条不然,我们必须再原地输出才能保证他是一个进度条,否则换行了怎么还叫进度条?

最简单的办法就是,再输出完毕后,把光标移动到行首,继续在那里输出更长的进度条即可实现,新的更长的进度条把旧的短覆盖,就形成了动画效果。

可以想到那个转义符了吧,那就是\ r。

转义符r就可以把光标移动到行首而不换行,转义符n就把光标移动到行首并且换行。

在python中,输出stdout(标准输出)可以使用sys.stdout.write

例如:

#!/usr/bin/env python
# -*- coding=utf-8 -*-
#Using GPL v2
#Author: ihipop@gmail.com
##2010-10-27 22:07
"""
Usage:
Just A Template
"""
from __future__ import division

import sys,time
j = '#'
if __name__ == '__main__':
  for i in range(1,61):
    j += '#'
    sys.stdout.write(str(int((i/60)*100))+'% ||'+j+'->'+"\r")
    sys.stdout.flush()
    time.sleep(0.5)
print

第二种思路是用转义符\b

转义符\b是退格键,也就是说把输出的光标往回退格子,这样就可以不用+=了,例如:

#!/usr/bin/env python
# -*- coding=utf-8 -*-
#Using GPL v2
#Author: ihipop@gmail.com
#2010-10-27 22:07
"""
Usage:
Just A Template
"""
from __future__ import division

import sys,time
if __name__ == '__main__':
  for i in range(1,61):
    sys.stdout.write('#'+'->'+"\b\b")
    sys.stdout.flush()
    time.sleep(0.5)
print

光标回退2格,写个#再回退,再写,达到增长的目的了

不过写这么多似乎是废话,在耳边常常听到一句话:那就是不要重复造轮子。实际上python有丰富发lib帮你实现这个东西,你完全可以把心思放在逻辑开发上而不用注意这些小细节

下面要介绍的就是这个类“progressbar”,使用easy_install可以方便的安装这个类库,其实就一个文件,拿过来放到文件同一个目录下面也直接可以import过来

如下图所示:

详解Python中如何写控制台进度条的整理

下面就是基本使用举例:

#!/usr/bin/env python
# -*- coding=utf-8 -*-
#Using GPL v2
#Author: ihipop@gmail.com
#2010-10-27 22:53
"""
Usage:
Just A Template
"""
from __future__ import division

import sys,time
from progressbar import *
total = 1000

#基本用法
progress = ProgressBar()
for i in progress(range(total)):
 time.sleep(0.01)

pbar = ProgressBar().start()
for i in range(1,1000):
  pbar.update(int((i/(total-1))*100))
  time.sleep(0.01)
pbar.finish()

#高级用法
widgets = ['Progress: ', Percentage(), ' ', Bar(marker=RotatingMarker('>-=')),
      ' ', ETA(), ' ', FileTransferSpeed()]
pbar = ProgressBar(widgets=widgets, maxval=10000000).start()
for i in range(1000000):
 # do something
 pbar.update(10*i+1)
 time.sleep(0.0001)
pbar.finish()

官方示例:http://code.google.com/p/python-progressbar/source/browse/progressbar/examples.py

# coding:utf-8
import sys
import time
from progressbar import AnimatedMarker, Bar, BouncingBar, Counter, ETA, \
  FileTransferSpeed, FormatLabel, Percentage, \
  ProgressBar, ReverseBar, RotatingMarker, \
  SimpleProgress, Timer

examples = []

def example(fn):
  try:
    name = 'Example %d' % int(fn.__name__[7:])
  except:
    name = fn.__name__

  def wrapped():
    try:
      sys.stdout.write('Running: %s\n' % name)
      fn()
      sys.stdout.write('\n')
    except KeyboardInterrupt:
      sys.stdout.write('\nSkipping example.\n\n')

  examples.append(wrapped)
  return wrapped

@example
def example0():
  pbar = ProgressBar(widgets=[Percentage(), Bar()], maxval=300).start()
  for i in range(300):
    time.sleep(0.01)
    pbar.update(i + 1)
  pbar.finish()

@example
def example1():
  widgets = ['Test: ', Percentage(), ' ', Bar(marker=RotatingMarker()),
        ' ', ETA(), ' ', FileTransferSpeed()]
  pbar = ProgressBar(widgets=widgets, maxval=10000000).start()
  for i in range(1000000):
    # do something
    pbar.update(10 * i + 1)
  pbar.finish()

@example
def example2():
  class CrazyFileTransferSpeed(FileTransferSpeed):
    """It's bigger between 45 and 80 percent."""

    def update(self, pbar):
      if 45 < pbar.percentage() < 80:
        return 'Bigger Now ' + FileTransferSpeed.update(self, pbar)
      else:
        return FileTransferSpeed.update(self, pbar)

  widgets = [CrazyFileTransferSpeed(), ' <<<', Bar(), '>>> ',
        Percentage(), ' ', ETA()]
  pbar = ProgressBar(widgets=widgets, maxval=10000000)
  # maybe do something
  pbar.start()
  for i in range(2000000):
    # do something
    pbar.update(5 * i + 1)
  pbar.finish()

@example
def example3():
  widgets = [Bar('>'), ' ', ETA(), ' ', ReverseBar('<')]
  pbar = ProgressBar(widgets=widgets, maxval=10000000).start()
  for i in range(1000000):
    # do something
    pbar.update(10 * i + 1)
  pbar.finish()

@example
def example4():
  widgets = ['Test: ', Percentage(), ' ',
        Bar(marker='0', left='[', right=']'),
        ' ', ETA(), ' ', FileTransferSpeed()]
  pbar = ProgressBar(widgets=widgets, maxval=500)
  pbar.start()
  for i in range(100, 500 + 1, 50):
    time.sleep(0.2)
    pbar.update(i)
  pbar.finish()

@example
def example5():
  pbar = ProgressBar(widgets=[SimpleProgress()], maxval=17).start()
  for i in range(17):
    time.sleep(0.2)
    pbar.update(i + 1)
  pbar.finish()

@example
def example6():
  pbar = ProgressBar().start()
  for i in range(100):
    time.sleep(0.01)
    pbar.update(i + 1)
  pbar.finish()

@example
def example7():
  pbar = ProgressBar() # Progressbar can guess maxval automatically.
  for i in pbar(range(80)):
    time.sleep(0.01)

@example
def example8():
  pbar = ProgressBar(maxval=80) # Progressbar can't guess maxval.
  for i in pbar((i for i in range(80))):
    time.sleep(0.01)

@example
def example9():
  pbar = ProgressBar(widgets=['Working: ', AnimatedMarker()])
  for i in pbar((i for i in range(50))):
    time.sleep(.08)

@example
def example10():
  widgets = ['Processed: ', Counter(), ' lines (', Timer(), ')']
  pbar = ProgressBar(widgets=widgets)
  for i in pbar((i for i in range(150))):
    time.sleep(0.1)

@example
def example11():
  widgets = [FormatLabel('Processed: %(value)d lines (in: %(elapsed)s)')]
  pbar = ProgressBar(widgets=widgets)
  for i in pbar((i for i in range(150))):
    time.sleep(0.1)

@example
def example12():
  widgets = ['Balloon: ', AnimatedMarker(markers='.oO<a href="http://www.jobbole.com/members/weiboyes8848" rel="external nofollow" >@*</a> ')]
  pbar = ProgressBar(widgets=widgets)
  for i in pbar((i for i in range(24))):
    time.sleep(0.3)

@example
def example13():
  # You may need python 3.x to see this correctly
  try:
    widgets = ['Arrows: ', AnimatedMarker(markers='←?↑?→?↓?')]
    pbar = ProgressBar(widgets=widgets)
    for i in pbar((i for i in range(24))):
      time.sleep(0.3)
  except UnicodeError:
    sys.stdout.write('Unicode error: skipping example')

@example
def example14():
  # You may need python 3.x to see this correctly
  try:
    widgets = ['Arrows: ', AnimatedMarker(markers='????')]
    pbar = ProgressBar(widgets=widgets)
    for i in pbar((i for i in range(24))):
      time.sleep(0.3)
  except UnicodeError:
    sys.stdout.write('Unicode error: skipping example')

@example
def example15():
  # You may need python 3.x to see this correctly
  try:
    widgets = ['Wheels: ', AnimatedMarker(markers='◐◓◑◒')]
    pbar = ProgressBar(widgets=widgets)
    for i in pbar((i for i in range(24))):
      time.sleep(0.3)
  except UnicodeError:
    sys.stdout.write('Unicode error: skipping example')

@example
def example16():
  widgets = [FormatLabel('Bouncer: value %(value)d - '), BouncingBar()]
  pbar = ProgressBar(widgets=widgets)
  for i in pbar((i for i in range(180))):
    time.sleep(0.05)

@example
def example17():
  widgets = [FormatLabel('Animated Bouncer: value %(value)d - '),
        BouncingBar(marker=RotatingMarker())]

  pbar = ProgressBar(widgets=widgets)
  for i in pbar((i for i in range(180))):
    time.sleep(0.05)

@example
def example18():
  widgets = [Percentage(),
        ' ', Bar(),
        ' ', ETA(),
        ' ', AdaptiveETA()]
  pbar = ProgressBar(widgets=widgets, maxval=500)
  pbar.start()
  for i in range(500):
    time.sleep(0.01 + (i < 100) * 0.01 + (i > 400) * 0.9)
    pbar.update(i + 1)
  pbar.finish()

@example
def example19():
  pbar = ProgressBar()
  for i in pbar([]):
    pass
  pbar.finish()

try:
  for example in examples:
    example()
except KeyboardInterrupt:
  sys.stdout('\nQuitting examples.\n')

再发一个类:

#!/usr/bin/env python
# -*- coding=utf-8 -*-
#Using GPL v2
#Author: ihipop@gmail.com
#2010-10-30 13:59
"""
Usage:
Just A Template
"""
class progressbarClass: 
  def __init__(self, finalcount, progresschar=None):
    import sys
    self.finalcount=finalcount
    self.blockcount=0
    #
    # See if caller passed me a character to use on the
    # progress bar (like "*"). If not use the block
    # character that makes it look like a real progress
    # bar.
    #
    if not progresschar: self.block=chr(178)
    else:        self.block=progresschar
    #
    # Get pointer to sys.stdout so I can use the write/flush
    # methods to display the progress bar.
    #
    self.f=sys.stdout
    #
    # If the final count is zero, don't start the progress gauge
    #
    if not self.finalcount : return
    self.f.write('\n------------------- % Progress -------------------\n')
    return

  def progress(self, count):
    #
    # Make sure I don't try to go off the end (e.g. >100%)
    #
    count=min(count, self.finalcount)
    #
    # If finalcount is zero, I'm done
    #
    if self.finalcount:
      percentcomplete=int(round(100*count/self.finalcount))
      if percentcomplete < 1: percentcomplete=1
    else:
      percentcomplete=100

    #print "percentcomplete=",percentcomplete
    blockcount=int(percentcomplete/2)
    #print "blockcount=",blockcount
    if blockcount > self.blockcount:
      for i in range(self.blockcount,blockcount):
        self.f.write(self.block)
        self.f.flush()

    if percentcomplete == 100: self.f.write("\n")
    self.blockcount=blockcount
    return

if __name__ == "__main__":
  from time import sleep
  pb=progressbarClass(8,"*")
  count=0
  while count<9:
    count+=1
    pb.progress(count)
    sleep(0.2)

另外,python cookbook中11.1节也提供了一个不错的进度条类,代码如下:

import sys

class progressbar(object):

  def __init__(self, finalcount, block_char='.'):
    self.finalcount = finalcount
    self.blockcount = 0
    self.block = block_char
    self.f = sys.stdout
    if not self.finalcount:
      return
    self.f.write('\n------------------ % Progress -------------------1\n')
    self.f.write(' 1 2 3 4 5 6 7 8 9 0\n')
    self.f.write('----0----0----0----0----0----0----0----0----0----0\n')

  def progress(self, count):
    count = min(count, self.finalcount)
    if self.finalcount:
      percentcomplete = int(round(100.0 * count / self.finalcount))
      if percentcomplete < 1:
        percentcomplete = 1
    else:
      percentcomplete = 100
    blockcount = int(percentcomplete // 2)
    if blockcount <= self.blockcount:
      return
    for i in range(self.blockcount, blockcount):
      self.f.write(self.block)
    self.f.flush()
    self.blockcount = blockcount
    if percentcomplete == 100:
      self.f.write("\n")

if __name__ == "__main__":
  from time import sleep
  pb = progressbar(8, "*")
  for count in range(1, 9):
    pb.progress(count)
    sleep(0.2)
  pb = progressbar(100)
  pb.progress(20)
  sleep(0.3)
  pb.progress(47)
  sleep(0.3)
  pb.progress(90)
  sleep(0.3)
  pb.progress(100)
  print "testing 1:"
  pb = progressbar(1)
  pb.progress(1)

运行结果如下图所示:

详解Python中如何写控制台进度条的整理

希望本文所述对大家Python程序设计的学习有所帮助。也希望大家多多支持三水点靠木。

Python 相关文章推荐
在Python中测试访问同一数据的竞争条件的方法
Apr 23 Python
Python网站验证码识别
Jan 25 Python
python实现决策树
Dec 21 Python
Python自定义函数实现求两个数最大公约数、最小公倍数示例
May 21 Python
Django项目开发中cookies和session的常用操作分析
Jul 03 Python
python字符串Intern机制详解
Jul 01 Python
学习和使用python的13个理由
Jul 30 Python
python如何实现不可变字典inmutabledict
Jan 08 Python
python实现简单学生信息管理系统
Apr 09 Python
python用TensorFlow做图像识别的实现
Apr 21 Python
python实现俄罗斯方块小游戏
Apr 24 Python
在keras 中获取张量 tensor 的维度大小实例
Jun 10 Python
python爬虫爬取网页表格数据
Mar 07 #Python
python使用mysql的两种使用方式
Mar 07 #Python
python表格存取的方法
Mar 07 #Python
Django中Model的使用方法教程
Mar 07 #Python
python使用opencv按一定间隔截取视频帧
Mar 06 #Python
python+ffmpeg视频并发直播压力测试
Mar 06 #Python
小白如何入门Python? 制作一个网站为例
Mar 06 #Python
You might like
星际争霸任务指南——虫族
2020/03/04 星际争霸
php实现从ftp服务器上下载文件树到本地电脑的程序
2009/02/10 PHP
php添加文章时生成静态HTML文章的实现代码
2013/02/17 PHP
探讨多键值cookie(php中cookie存取数组)的详解
2013/06/06 PHP
PHP学习笔记(二) 了解PHP的基本语法以及目录结构
2014/08/04 PHP
Jquery 常用方法经典总结
2010/01/28 Javascript
javascript中的delete使用详解
2013/04/11 Javascript
js substr支持中文截取函数代码(中文是双字节)
2013/04/17 Javascript
javascript动态添加、修改、删除对象的属性与方法详解
2014/01/27 Javascript
FullCalendar日历插件应用之数据展现(一)
2015/12/23 Javascript
javascript输出AscII码扩展集中的字符方法
2016/12/26 Javascript
详解nodejs中express搭建权限管理系统
2017/09/15 NodeJs
微信小程序 按钮滑动的实现方法
2017/09/27 Javascript
Vue实现web分页组件详解
2017/11/28 Javascript
javaScript实现鼠标在文字上悬浮时弹出悬浮层效果
2020/04/12 Javascript
对vue 键盘回车事件的实例讲解
2018/08/25 Javascript
vue把输入框的内容添加到页面的实例讲解
2019/11/11 Javascript
[02:07]DOTA2新英雄展现中国元素,完美“圣典”亮相央视
2016/12/19 DOTA
Python将图片批量从png格式转换至WebP格式
2020/08/22 Python
python扫描proxy并获取可用代理ip的实例
2017/08/07 Python
分析Python读取文件时的路径问题
2018/02/11 Python
简单实现python聊天程序
2018/04/01 Python
Python实现的调用C语言函数功能简单实例
2019/03/13 Python
什么是python的函数体
2020/06/19 Python
html5弹跳球示例代码
2013/07/23 HTML / CSS
利用三角函数在canvas上画虚线的方法
2018/01/11 HTML / CSS
聘任书的写作格式及范文
2014/03/29 职场文书
建材投资建议书
2014/05/16 职场文书
学校运动会通讯稿
2015/07/18 职场文书
尊师重教主题班会
2015/08/14 职场文书
礼貌问候语大全
2015/11/10 职场文书
vue3中的组件间通信
2021/03/31 Vue.js
用python删除文件夹中的重复图片(图片去重)
2021/05/12 Python
html中显示特殊符号(附带特殊字符对应表)
2021/06/21 HTML / CSS
漫改真人电影「萌系男友是燃燃的橘色」公开先导视觉图
2022/03/21 日漫
《巫师》是美食游戏?CDPR10月将推出《巫师》官方食谱
2022/04/03 其他游戏