Default key for Python builtin max/min functions
<p>The documentation for the built-in functions <code>max</code> and <code>min</code> in Python indicate that the <code>key</code> parameter should operate like it does in the <code>sort</code> function. In other words, I should be able to do this:</p>

<pre><code>a = [1, 2, 3, 4]
max(a, key=None)
</code></pre>

<p>However, this raises an error:
<code>TypeError: 'NoneType' object is not callable</code></p>

<p>But, if I do something similar with the <code>sort</code> function, I get the expected results:</p>

<pre><code>a = [1, 2, 3, 4]
a.sort(key=None)
</code></pre>

<p>No error is generated and the default sort is used. Several books also imply that I should be able to get away with the same behavior in the <code>max</code> and <code>min</code> functions. See this excerpt from <a href="http://books.google.com/books?id=JnR9hQA3SncC&amp;lpg=PA58&amp;ots=Jb3UEt090u&amp;dq=set%20key%20argument%20to%20none%20python%20max&amp;pg=PA58#v=onepage&amp;q=set%20key%20argument%20to%20none%20python%20max&amp;f=false" rel="nofollow">Python in a Nutshell</a>.</p>

<p>Is this really the default behavior of the <code>max</code> and <code>min</code> functions? Should it be? Shouldn't they match the sort function?</p>
