Python文件操作自制小练习

for b in range(29):
    a = open('D:\a\' + str(b+1) + '.srt','r') #读取文件
    lines = len(a.readlines()) #测量文件行数
    a.seek(0,0) #测量文件行数
    c = open('c.txt','a') #新建文件
    if b > 0:
        ce = '

This is lesson ' + str(b+1) + '

' #标题行
    if b == 0:
        ce = 'This is lesson ' + str(b+1) + '

' #标题行
    c.write(ce)
    g = 0
    while g < lines:
        e = a.readline()
        g += 1
        e = a.readline()
        g += 1
        e = a.readline()
        g += 1
        while(e != '
' and e != '' ): 
            if '&gt;&gt;' in e:
                e = e[8:]
            c.write(e)
            e = a.readline()
            g += 1                    
    a.close()
    c.close()

目标：提取字幕文件里的文字部分

坑、要点：

1）文件行数：

lines = len(a.readlines())
a.seek(0,0)

2）追加写入模式'a'

3）文件读取到空行是' '，文件读取到结尾没了是 ''

例子：1.srt

1
00:00:00,730 --> 00:00:02,050
Hi. Welcome to Version Control.

2
00:00:02,050 --> 00:00:04,300
I'm Carolyn, one of your instructors for the course.

3
00:00:04,300 --> 00:00:05,350
>> And I'm Sarah, your other instructor.

4
00:00:05,350 --> 00:00:08,340
In this course, we'll cover the concept of Version Control and

5
00:00:08,340 --> 00:00:09,960
why you might want to use it.

6
00:00:09,960 --> 00:00:12,610
>> Yeah. So, Version Control is sort of like having a giant undo button for

7
00:00:12,610 --> 00:00:13,530
your project.

8
00:00:13,530 --> 00:00:15,720
>> You mean like this one?

例子：3.srt

1
00:00:00,310 --> 00:00:01,630
Hey, I'm here with Larry, and

2
00:00:01,630 --> 00:00:04,019
he's been having a problem with
a webpage he's been working on.

3
00:00:04,019 --> 00:00:06,810
I think this is a great opportunity to
both help Larry out with his problem and

4
00:00:06,810 --> 00:00:09,230
to show you what version
control can be useful for.

5
00:00:09,230 --> 00:00:10,700
>> Yeah, so,
I've been working on a website, and

6
00:00:10,700 --> 00:00:12,540
it looks a lot different
than it did before.

7
00:00:12,540 --> 00:00:13,610
There used to be a banner at the top.