python文件输出不完整。

Question

刚刚学python，小白一枚，今天拿python来去除一段代码前面的行号，
待处理文件看起来是这样的
001package org.apche.lucene.demo;
002import java.io.BufferedReader;
…

python代码是这么写的（在ipython环境中）

f = open("in")
lines = f.readlines()
fout = open("out", "w")
for line in lines:
    fout.write(line[3:])
exit()

结果输出文件当中只有117行代码，而输入文件中明明有239行。
不是很懂其中的原因，考虑过缓冲区未写出的问题，但是exit()之后输出文件仍然只有117行代码。求大神指点，多谢！

Answer 1

Guess: There is a character after line 117 that allows readline() to determine the end of the file

You can add a breakpoint and try it step by step.

Answer 2

You can check len(lines) to see if it is 239.

And I suggest you add

fout.close()
f.close()

Answer 3

Maybe it’s because in this file, there are more than 100 lines of text with a length less than 3