title: Pandas drop rows if only first column has data
body: <p>I have a pandas dataframe like so:</p>
  <pre><code>Unnamed:1 Unnamed:2 .... Unnamed:20
  Data      NaN       .... NaN
  id        name      .... year
  .
  .
  .
  Data2     NaN       .... NaN
  id        name      .... year
  .
  .
  .
  Footnotes NaN       .... NaN
  </code></pre>
  <p>So, in order to clean this data, I first want to drop all rows where only the first column has data and rest all columns are NaN. So my dataframe will become like so:</p>
  <pre><code>Unnamed:1 Unnamed:2 .... Unnamed:20
  id        name      .... year
  .
  .
  .
  id        name      .... year
  .
  .
  .
  </code></pre>
  <p>Then make the first row as column names and drop any further occurrences of it and so finally my dataframe should be like this:</p>
  <pre><code>id        name      .... year
  .
  .
  .
  </code></pre>