title: Unite the columns of the dataframe based on the type of character they contain
body: <p>So I have the following dataframe of the salaries of former NBA players. The original data was on a .txt file, that's why my dataframe look like this:</p>
  <pre><code>  V1         V2         V3          V4         V5         V6
  Vinnie     Del        Negro       .....      150000
  Moses      Malone     .....                  75000
  Kevin      Willis     ......      150000
  Joe        Barry      Carrol      .....                 750000
  Doc        Rivers     ....                              230000
  Antoine    Carr       ......      85000
  Hot        Rod        Williams    ...                   45000
  </code></pre>
  <p>This is just a glimpse of the real dataframe, which contains 350 rows and 7 columns (Non column is fully empty). What I want to do is to rearrange this dataframe in order to ultimately have just two columns, one corresponding to the name of the player and the other corresponding to his respective salary:</p>
  <pre><code>   name                 salary
  Vinnie Del Negro        150000
  Moses Malone            75000
  Kevin Willis            150000
  Joe Barry Carrol        750000
  Doc Rivers              230000
  Antoine Carr            85000
  Hot Rod Williams        45000
  </code></pre>
  <p>Maybe this is very simple, but I've been trying to work around it for a couple of hours now and I can't seem to get any closer.
  I think the best approach would be something that puts in the first column all the alphabetic cells and in the second column all the numeric cells. The only issue with this is that since the original dataframe was a .txt file, all the columns are expressed as.characters().</p>
  <p>Hope you can help me!</p>
  <p>Thanks</p>