python .rstrip removes one additional character
<p>I try to remove seconds from date:</p>

<pre><code>&gt;&gt;&gt; import datetime
&gt;&gt;&gt; test1 = datetime.datetime(2011, 6, 10, 0, 0)
&gt;&gt;&gt; test1
datetime.datetime(2011, 6, 10, 0, 0)
&gt;&gt;&gt; str(test1)
'2011-06-10 00:00:00'
&gt;&gt;&gt; str(test1).rstrip('00:00:00')
'2011-06-10 '
&gt;&gt;&gt; str(test1).rstrip(' 00:00:00')
'2011-06-1'
</code></pre>

<p>Why 0 at end of '10' is removed?</p>
