pandas converting floats to strings without decimals
<p>I have a dataframe</p>

<pre><code>df = pd.DataFrame([
        ['2', '3', 'nan'],
        ['0', '1', '4'],
        ['5', 'nan', '7']
    ])

print df

   0    1    2
0  2    3  nan
1  0    1    4
2  5  nan    7
</code></pre>

<p>I want to convert these strings to numbers and sum the columns and convert back to strings.</p>

<p>Using <code>astype(float)</code> seems to get me to the number part.  Then summing is easy with <code>sum()</code>.  Then back to strings should be easy too with <code>astype(str)</code></p>

<pre><code>df.astype(float).sum().astype(str)

0     7.0
1     4.0
2    11.0
dtype: object
</code></pre>

<p>That's almost what I wanted.  I wanted the string version of integers.  But floats have decimals.  How do I get rid of them?</p>

<p>I want this</p>

<pre><code>0     7
1     4
2    11
dtype: object
</code></pre>