擅长:python、mysql、java
<pre><code>from collections import Counter
import re
reg = re.compile('\S{4,}')
s = "hello this is hello this is baby baby baby baby hello"
c = Counter(ma.group() for ma in reg.finditer(s))
print c
</code></pre>
<p>结果</p>
<pre><code>Counter({'baby': 4, 'hello': 3, 'this': 2})
</code></pre>
<p>另外:</p>
<pre><code>from collections import defaultdict
d = defaultdict(int)
s = "hello this is hello this is baby baby baby baby hello"
for w in s.split():
if len(w)>=4:
d[w] += 1
print d
</code></pre>