<p>我第一次尝试python中的任何东西时,我甚至无法获得for循环来更新元素。拜托,我没看见什么?你知道吗</p>
<p>我在一个文本文件里有这些数据</p>
<blockquote>
<p>Y|Contents/MacOS/Safari|1500<br/>
N|Contents/MacOS/firefox|1200<br/>
Y|Contents/MacOS/Evernote|1100</p>
</blockquote>
<p>我想把第二行的N改成Y,它在循环内部打印出我想要的形式,而不是在循环外部?这是什么?你知道吗</p>
<pre><code>def setTrackable(self,appName):
lookfor = 'Contents/MacOS/'+appName
with open (self.__dataFile,"r") as myfile:
data = myfile.readlines()
for line in data:
temp = line.split("|")
if (temp[1] == lookfor):
line = 'Y|'+lookfor+"|"+temp[2]
print("line: "+line)
print (data[1])
with open (self.__dataFile, "w") as myfile:
myfile.writelines(data)
</code></pre>
<p>使用枚举并相应地修改<code>data</code>:</p>
<pre><code>for i, line in enumerate(data):
temp = line.split("|")
if (temp[1] == lookfor):
line = '|'.join(['Y', lookfor, temp[2]])
data[i] = line
print("line: "+line)
</code></pre>