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
Python实现抓取网页并且解析的实例
Sep 20 Python
在Python中用get()方法获取字典键值的教程
May 21 Python
Python正则表达式如何进行字符串替换实例
Dec 28 Python
python筛选出两个文件中重复行的方法
May 31 Python
Python判断字符串是否为字母或者数字(浮点数)的多种方法
Aug 03 Python
python批量复制图片到另一个文件夹
Sep 17 Python
Python的高阶函数用法实例分析
Apr 11 Python
Pyqt5实现英文学习词典
Jun 24 Python
Python 模拟生成动态产生验证码图片的方法
Feb 01 Python
Python3+selenium实现cookie免密登录的示例代码
Mar 18 Python
Matplotlib animation模块实现动态图
Feb 25 Python
Python OpenCV超详细讲解读取图像视频和网络摄像头
Apr 02 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
使用Limit参数优化MySQL查询的方法
2008/11/12 PHP
PHP入门学习笔记之一
2010/10/12 PHP
phpcms手机内容页面添加上一篇和下一篇
2015/06/05 PHP
Prototype中dom对象方法汇总
2008/09/17 Javascript
写了10年的Javascript也未必全了解的连续赋值运算
2011/03/25 Javascript
一个简单的JS鼠标悬停特效具体方法
2013/06/17 Javascript
jquery动态添加删除div 具体实现
2013/07/20 Javascript
使用js修改客户端注册表的方法
2013/08/09 Javascript
ExtJS[Desktop]实现图标换行示例代码
2013/11/17 Javascript
jQuery.parseJSON(json)将JSON字符串转换成js对象
2014/07/27 Javascript
Bootstrap每天必学之日期控制
2016/03/07 Javascript
js中判断变量类型函数typeof的用法总结
2016/08/09 Javascript
Angular 4 指令快速入门教程
2017/06/07 Javascript
vue引入jq插件的实例讲解
2017/09/12 Javascript
浅谈Node.js CVE-2017-14849 漏洞分析(详细步骤)
2017/11/10 Javascript
vue form 表单提交后刷新页面的方法
2018/09/04 Javascript
详解vue中async-await的使用误区
2018/12/05 Javascript
微信小程序实现原生步骤条
2019/07/25 Javascript
解决vue-router 二级导航默认选中某一选项的问题
2019/11/01 Javascript
vue配置多代理服务接口地址操作
2020/09/08 Javascript
vue缓存之keep-alive的理解和应用详解
2020/11/02 Javascript
JavaScript代码实现简单计算器
2020/12/27 Javascript
Python字符遍历的艺术
2008/09/06 Python
pandas数据选取:df[] df.loc[] df.iloc[] df.ix[] df.at[] df.iat[]
2020/04/24 Python
Python Tricks 使用 pywinrm 远程控制 Windows 主机的方法
2020/07/21 Python
Python改变对象的字符串显示的方法
2020/08/01 Python
canvas进阶之如何画出平滑的曲线
2018/10/15 HTML / CSS
英国鲜花速递:Serenata Flowers
2018/04/03 全球购物
JACK & JONES荷兰官网:男士服装和鞋子
2021/03/07 全球购物
幼师专业毕业生自荐信
2013/09/29 职场文书
班会关于环保演讲稿
2013/12/29 职场文书
《放飞蜻蜓》教学反思
2014/04/27 职场文书
幼儿园门卫岗位职责范本
2014/07/02 职场文书
党的群众路线对照检查材料(个人)
2014/09/24 职场文书
2015年青年志愿者工作总结
2015/05/20 职场文书
《秋天的图画》教学反思
2016/02/19 职场文书