Pandas dataframe: how to group by values in a column and create new columns out of grouped values
<p>I have a dataframe with two columns:</p>

<pre><code>x y
0 1
1 1
2 2
0 5
1 6
2 8
0 1
1 8
2 4
0 1
1 7
2 3
</code></pre>

<p>What I want is:</p>

<pre><code>x val1 val2 val3 val4
0 1 5 1 1
1 1 6 8 7
2 2 8 4 3
</code></pre>

<p>I know that the values in column x are repeated all N times.</p>