擅长:python、mysql、java
<p>python2不支持只支持关键字的参数。如果您真的希望Python 2函数具有只能通过关键字传递的参数,则需要使用<code>**kwargs</code>并亲自验证关键字参数:</p>
<pre><code>def my_max(*args, **kwargs):
'''Emulate the built-in max, including the keyword-only key argument.'''
key = kwargs.pop('key', None)
if kwargs:
raise TypeError('my_max() got an unexpected keyword argument {!r}'.format(next(iter(kwargs))))
if key is None:
# max doesn't support key=None
return max(*args)
else:
return max(*args, key=key)
</code></pre>