擅长:python、mysql、java
<p>这就是你要找的吗?在</p>
<pre><code>>>> def abc(a=None,b=None):
... if a is not None: print a
... if b is not None: print b
...
>>> abc("a")
a
>>> abc("a","b")
a
b
>>> abc()
>>>
</code></pre>