python实现进度条

先说一下文本系统的控制符：
\r：   将光标移动到当前行的首位而不换行；
\n：   将光标移动到下一行，并不移动到首位；
\r\n： 将光标移动到下一行首位。

环境：
[email protected]:/alex/py/jingdutiao# python3
Python 3.5.2 (default, Jul  5 2016, 12:43:10)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 

方式1：
[email protected]:/alex/py/jingdutiao# cat test1.py
#!/usr/bin/env python
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

[email protected]:/alex/py/jingdutiao# python3 test1.py
98% ############################################################->

方式2：
[email protected]:/alex/py/jingdutiao# cat test4.py
#!/usr/bin/env python
# -*- coding:utf-8 -*-
__author__ = ‘l‘

import sys
from time import sleep
def viewBar(i):
    """
    进度条效果
    :param i:
    :return:
    """
    output = sys.stdout
    for count in range(0, i + 1):
        second = 0.1
        sleep(second)
        output.write(‘\rcomplete percent ----->:%.0f%%‘ % count)
    output.flush()

viewBar(100)
[email protected]:/alex/py/jingdutiao# python3 test4.py
complete percent ----->:100%

方式3：
tqdm模块
    tqdm是一个快速、扩展性强的进度条工具库，
    其githup地址：https://github.com/tqdm/tqdm 

1）安装：
直接使用pip安装：
    pip install tqdm
2）使用：
from time import sleep
from tqdm import tqdm
for i in tqdm(range(1, 500)):
    sleep(0.01)

自己实操：在ubuntu上默认安装到2.7环境变量里去了
[email protected]:/alex/py/jingdutiao# pip install tqdm
Collecting tqdm
  Downloading tqdm-4.8.4-py2.py3-none-any.whl
Installing collected packages: tqdm
Successfully installed tqdm-4.8.4
You are using pip version 8.1.1, however version 8.1.2 is available.
You should consider upgrading via the ‘pip install --upgrade pip‘ command.

pip install --upgrade pip
pip install tqdm
pip -V
cd /usr/local/lib/python2.7/dist-packages/
cp -r  tqdm tqdm-4.8.4.dist-info/ /usr/local/lib/python3.5/dist-packages
[email protected]:/alex/py/jingdutiao# cat test5.py
from time import sleep
from tqdm import tqdm
for i in tqdm(range(1, 500)):
    sleep(0.01)
[email protected]:/alex/py/jingdutiao# python3  test5.py
100%|████████████████████████████████████████████████████████████████████████| 499/499 [00:05<00:00, 92.20it/s

方式4：
[email protected]:/alex/py/jingdutiao# cat   test2.py 

class ProgressBar():
  def __init__(self, width=50):
    self.pointer = 0
    self.width = width
  def __call__(self,x):
     # x in percent
     self.pointer = int(self.width*(x/100.0))
     return "|" + "#"*self.pointer + "-"*(self.width-self.pointer)+ "|\n %d percent done" % int(x)

if __name__ == ‘__main__‘:
    import time,os
pb = ProgressBar()
for i in range(101):
    os.system(‘clear‘)
    print( pb(i))
    time.sleep(0.1)

[email protected]:/alex/py/jingdutiao#
执行结果：
|#################################################-|
percent done
|##################################################|   #输出100行内容，但是在屏幕会实时清屏，只展示1行
percent done

方式5：
[email protected]:/alex/py/jingdutiao# python3   test3.py
====================================================================================================>100%
#cat test3.py
import sys
import time
def view_bar(num,total):
    rate = num / total
    rate_num = int(rate * 100)
    #r = ‘\r %d%%‘ %(rate_num)
    r = ‘\r%s>%d%%‘ % (‘=‘ * rate_num, rate_num,)
    sys.stdout.write(r)
    sys.stdout.flush
if __name__ == ‘__main__‘:
    for i in range(0, 101):
        time.sleep(0.1)
        view_bar(i, 100)