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：

 
 
 
 
 

Python

 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
#!/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：

 
 
 
 
 

Python

 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
#!/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的百度云网盘搜索

下面要介绍的就是这个类“progressbar”(http://code.google.com/p/python-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：

下面就是基本使用举例：

 
 
 
 
 
 

Python

 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
#!/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

 
 
 
 
 
 

Python

 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
# 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">@*</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：

 
 
 
 
 
 

Python

 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
#!/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：

 
 
 
 
 
 

Python

 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
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：

Python中如何写控制台进度条的整理的更多相关文章

  1. Python中使用print打印进度条

    import time for i in range(0,101,2): time.sleep(0.1) char_num = i//2 #打印多少个'*' per_str = '\r%s%% : % ...

  2. 用python的time库写一个进度条

    运算符 算数运算 如a=10,b=20 +两个数相加 a+b=30 -两个数相减 a-b=-10 两个数相乘 a****b =200 /两个数相除b/a=2 %取模,并返回余数b%a=0 幂,a*** ...

  3. 用C#实现控制台进度条

    在写一些简单的控制台测试程序时,经常希望能够在程序运行的过程中实现进度条的功能以便查看程序运行的速度或者进度.本文以C#为例,实现简单的控制台进度条,以供大家参考(本文底部附下载地址). 1.实现效果 ...

  4. [c#]控制台进度条的示例

    看到[vb.net]控制台进度条的示例 感觉很好玩,翻译成C#版. using System; using System.Collections.Generic; using System.Linq; ...

  5. Python 控制台进度条的实现

    进行爬虫等耗时的任务时,有时会想在控制台输出进度条,以显示当前任务进度.这里总结了两种方法. 方法1:使用tqdm模块 示例代码: from time import sleep from tqdm i ...

  6. [ python ] 使用sys模块实现进度条

    在写网络IO传输的时候, 有时候需要进度条来显示当前传输进度,使用 sys 模块就可以实现: sys.stdout.write() 这个函数在在控制台输出字符串不会带任何结尾,这就意味着这个输出还没有 ...

  7. 用 Python 给程序加个进度条，让你的看起来更炫酷？

    对于开发或者运维来说,使用 Python 去完成一些跑批任务,或者做一些监控事件是非常正常的情况.那么如何有效地监控任务的进度?除了在任务中加上 Log 外,还能不能有另一种方式来了解任务进展到哪一步 ...

  8. css3实现loading效果--当页面加载过程中显示Loading的进度条，全部加载完成之后进度条消失

    一个页面等图片资源全部加载完成,会需要很长时间,用户体验会很差,所以我们需要loading来掩盖这个漫长的过程! emmm,定时器?写个定时器还要清除,万一造成内存泄露?定时器之间还会互相影响,呼呼呼 ...

  9. ruby 编写控制台进度条

    ruby 中,$stdout.flush 让控制台当前行内容可以重写,以此我们可以做出进度条的效果. def set_progress(index, char = '*') print (char * ...

随机推荐

  1. How to: Implement a Windows Communication Foundation Service Contract

    This is the second of six tasks required to create a basic Windows Communication Foundation (WCF) se ...

  2. codeigniter实现ajax分页

    <?php /** *417 add 主要是实现ajax分页 **/ class MY_Pagination extends CI_Pagination{ public function __c ...

  3. C# 操作 Word 修改word的高级属性中的自定义属性

    为 Microsoft Word 创建自动化客户端 启动 Visual Studio .NET. 在文件菜单上,单击新建,然后单击项目.从 Visual C# 项目类型中选择 Windows 应用程序 ...

  4. linux文件属性详解

    Linux 文件或目录的属性主要包括:文件或目录的节点.种类.权限模式.链接数量.所归属的用户和用户组.最近访问或修改的时间等内容.具体情况如下: 命令: ls -lih 输出: [root@loca ...

  5. asp.net基础

    这篇主要讲述以下基础知识: Request对象 Response对象 Server对象 Cookie对象 Application对象 ViewState对象 <%%>与<%=%> ...

  6. [MarsZ]程序猿谈大学之大学应该学好哪些课程

    大家好,我是MarsZ,上次给大家带来了程序猿Mars谈大学之大学应该怎么过 ,反响还不错(……),这次继续给大家分析一下大学应该学好哪些课程. 首先必须说明两点:一,以下我说的仅代表个人观点.二,仅 ...

  7. iOS开发——GCD多线程详解

    GCD多线程详解 1. 什么是GCD Grand Central Dispatch 简称(GCD)是苹果公司开发的技术,简单来说,GCD就是iOS一套解决多线程的机制,使用GCD能够最大限度简化多线程 ...

  8. Hadoop系列（一）hadoop2.2.0源码编译

    操作系统:Centos 所需条件:能上网 编译所需工具: apache-ant-1.9.2-bin.tar.gz apache-maven-3.0.5-bin.tar.gz findbugs-2.0. ...

  9. java 小结1（static ，final，泛型）

    static,final. (1)final: final:属于“终态”,意思就是不可以改变.可以修饰非抽象类,非抽象类的方法等.反正就是不能够再改变赋值了. 注意:1)fina类不能被继承,所以它没 ...

  10. Codeforces149E - Martian Strings(KMP)

    题目大意 给定一个字符串T,接下来有n个字符串,对于每个字符串S,判断是否存在T[a-b]+T[c-d]=S(1 ≤ a ≤ b < c ≤ d ≤ length(T)) 题解 对于每个字符串S ...