Is it possible to have a single unique index for multiple rows in pandas?
<p>Is it possible to have a single unique index for multiple rows in pandas? 
Example:</p>

<pre><code>index country value
1 NL 'hi'
2 NL 'wet'
3 SWE '4'
4 SWE 'maybe'
</code></pre>

<p>So, in this example I cannot set NL as an index because it's not unique. Is it not possible to have multiple rows for a index in pandas? </p>