Pandas Groupby and Sum Only One Column
<p>So I have a dataframe, <code>df1</code>, that looks like the following:</p>
<pre><code>       A      B      C
1     foo    12    California
2     foo    22    California
3     bar    8     Rhode Island
4     bar    32    Rhode Island
5     baz    15    Ohio
6     baz    26    Ohio
</code></pre>
<p>I want to group by column <code>A</code> and then sum column <code>B</code> while keeping the value in column <code>C</code>. Something like this:</p>
<pre><code>      A       B      C
1    foo     34    California
2    bar     40    Rhode Island
3    baz     41    Ohio
</code></pre>
<p>The issue is, when I say</p>
<pre><code>df.groupby('A').sum()
</code></pre>
<p>column <code>C</code> gets removed, returning</p>
<pre><code>      B
A
bar  40
baz  41
foo  34
</code></pre>
<p>How can I get around this and keep column <code>C</code> when I group and sum?</p>