擅长:python、mysql、java
<pre><code>>>> d = {'i:crid1': 1, 'c:crid1': 1, 'i:crid2': 1, 'c:crid2': 1}
>>> %timeit dict((k, v) for k, v in d.iteritems() if k.startswith('c:'))
# 100000 loops, best of 3: 4.12 us per loop
>>> import re
>>> patt = re.compile('^c:.')
>>> %timeit dict((k, v) for k, v in d.iteritems() if patt.match(k))
# 100000 loops, best of 3: 5.22 us per loop
>>> { k:v for k,v in d.iteritems() if k.startswith('c:') }
# 100000 loops, best of 3: 2.22 us per loop
</code></pre>