擅长:python、mysql、java
<p>打开文件时,<code>r+</code>命令Python附加到文件。听起来你想覆盖这个文件。<code>w+</code>标志将为您实现这一点,请参见<a href="https://docs.python.org/2/library/functions.html#open" rel="nofollow">Python docs on open()</a></p>
<blockquote>
<p>Modes 'r+', 'w+' and 'a+' open the file for updating (reading and writing); note that 'w+' truncates the file.</p>
</blockquote>
<pre><code>f = open ('testLC31.txt', 'w+')
def after_semi(f):
for line in f:
yield line.split(';')[0]
for line in after_semi(f):
f.write('!\n' + line)
f.close()
</code></pre>
<p>我建议使用<code>with</code>来确保文件总是被关闭,这应该为您指明正确的方向:</p>
<pre><code>with open ('testLC31.txt', 'w+') as fout:
for line in after_semi(f):
fout.write('!\n' + line)
</code></pre>
<p>希望有帮助!你知道吗</p>