擅长:python、mysql、java
<p>使用<code>regex</code>:</p>
<pre><code>>>> import re
>>> with open('filename') as f:
... ans = []
... for line in f:
... matches = re.findall(r'(?<!\w)(\$\w+)', line)
... ans.extend(matches)
...
>>> print ans
['$severity', '$description', '$eventID', '$eventURL', '$alertLevel', '$eventStart', '$eventSourceCount', '$eventSourceTable', '$eventDestCount']
</code></pre>
<p>现在使用<code>str.join</code>获得预期的输出:</p>
^{pr2}$