擅长:python、mysql、java
<p>不是monkey-patching,只是重新定义了<code>sum</code>,使其同样适用于字符串。在</p>
<pre><code>>>> import __builtin__
def sum(seq, start = 0):
if all(isinstance(x,str) for x in seq):
return "".join(seq)
else:
return __builtin__.sum(seq, start)
...
>>> sum([4,5,6,7])
22
>>> sum(['s','t','a','c','k'])
'stack'
</code></pre>