擅长:python、mysql、java
<p>标志<code>re.MULTILINE</code>是必需的</p>
<pre><code>import re
s = '''one line
identifier = None ,) and
another line'''
pat = '^identifier\s*=\s*(None)+'
m = re.search(pat,s)
try:
gr = m.group(1)
print gr,type(gr)
except:
print ' No match has been found '
print ' -'
m = re.search(pat,s,re.M)
try:
gr = m.group(1)
print gr,type(gr)
except:
print ' No match has been found '
</code></pre>
<p>结果</p>
<pre><code> No match has been found
-
None <type 'str'>
</code></pre>