character classification of strings in python
<pre><code>def isLower(ch):
    return ch in string.lowercase

def isLower(ch):
    return 'a' &lt;= ch &lt;= 'z'

def isLower(ch):
    return string.find(string.lowercase, ch) != -1
</code></pre>

<p>Which version of isLower you think will be
fastest? What are the other reasons besides speed to prefer one or
the other?</p>
