title: How to select rows based on unlabelled first column of a multidimentional dataframe in pandas in python?
body: <p>I have the following dataframe:</p>
  
  <pre><code>             1   2   3   4   5   6   7   8   9   10
  cat   cat     1   1   1   1   1   1   0   0   1   1
        dog     1   0   1   1   1   1   0   0   1   1
        fox     0   0   0   0   0   0   0   0   0   0
        jumps   1   0   1   1   1   0   0   1   1   1
        over    1   0   1   1   1   1   0   0   1   1
        the     1   0   1   1   1   1   0   0   1   1
  dog   cat     1   1   0   1   1   1   0   0   1   0
        dog     1   1   1   1   1   1   0   0   1   1
        fox     1   1   1   1   1   1   0   0   1   1
        jumps   1   1   1   1   1   1   0   1   1   1
        over    1   1   1   1   1   1   0   0   1   1
        the     1   1   1   1   1   1   1   0   1   1
  fox   cat     0   0   0   0   0   0   0   0   0   0
        dog     1   1   1   1   1   1   0   0   1   1
        fox     1   1   1   1   1   1   0   0   1   1
        jumps   1   1   1   1   1   1   0   1   1   1
        over    1   1   1   1   1   1   0   0   1   1
        the     1   1   1   1   1   1   1   0   1   1
  jumps cat     1   1   0   1   0   1   1   0   1   0
        dog     1   1   1   1   1   1   1   0   1   0
        fox     1   1   1   1   1   1   1   0   1   0
        jumps   1   1   1   1   1   1   0   0   1   0
        over    1   0   1   1   1   0   0   1   1   0
        the     1   0   1   1   1   1   0   0   1   0
  over  cat     1   1   0   1   1   1   0   0   1   0
        dog     1   1   1   1   1   1   0   0   1   0
        fox     1   1   1   1   1   1   0   0   1   0
        jumps   1   1   0   1   0   1   1   0   1   0
        over    1   1   1   1   1   1   0   0   1   0
        the     1   0   1   1   1   0   0   1   1   0
  the   cat     1   1   0   1   1   1   0   0   1   0
        dog     1   1   1   1   1   1   0   1   1   0
        fox     1   1   1   1   1   1   0   1   1   0
        jumps   1   1   0   1   1   1   0   0   1   0
        over    1   1   0   1   0   1   1   0   1   0
        the     1   1   1   1   1   1   0   0   1   0
  </code></pre>
  
  <p>As you can see the first two columns are unlabelled. I want to select all rows where column1 == 'dog'</p>
  
  <p>So that I end up with this:</p>
  
  <pre><code>dog   cat     1   1   0   1   1   1   0   0   1   0
  dog   dog     1   1   1   1   1   1   0   0   1   1
  dog   fox     1   1   1   1   1   1   0   0   1   1
  dog   jumps   1   1   1   1   1   1   0   1   1   1
  dog   over    1   1   1   1   1   1   0   0   1   1
  dog   the     1   1   1   1   1   1   1   0   1   1
  </code></pre>
  
  <p>If it had a label, the solution would have been: </p>
  
  <pre><code>print(df.loc[df['label'] == 'dog'])
  </code></pre>
  
  <p>But because it doesn't have a label, how do I achieve that?
  Any suggestions will be highly appreciated. Thank you.</p>