title: Python Pandas: DataFrame filter negative values
body: <p>I was wondering how I can remove all indexes that containing negative values inside their column. I am using Pandas <code>DataFrames</code>. </p>
  
  <p><a href="http://pandas.pydata.org/pandas-docs/dev/generated/pandas.DataFrame.html" rel="noreferrer">Documentation Pandas DataFrame</a></p>
  
  <p>Format:</p>
  
  <p><strong>Myid</strong> - <strong>valuecol1</strong> - <strong>valuecol2</strong> - <strong>valuecol3</strong> -... <strong>valuecol30</strong></p>
  
  <p>So my <code>DataFrame</code> is called <code>data</code></p>
  
  <p>I know how to do this for 1 column:</p>
  
  <pre><code>data2 = data.index[data['valuecol1'] &gt; 0]
  data3 = data.ix[data3]
  </code></pre>
  
  <p>So I only get the ids where <code>valuecol1 &gt; 0</code>, how can I do some kind of <code>and</code> statement?</p>
  
  <p><code>valuecol1 &amp;&amp; valuecol2 &amp;&amp; valuecol3 &amp;&amp; ... &amp;&amp; valuecol30 &gt; 0</code> ? </p>