title: Pandas - drop last column of DataFrame
body: <p>I have a DataFrame and I would like to drop the last column of it. Until now I had just been dropping what I believed to be the final column with </p>
  
  <p><code>if len(fish_frame.columns) == 4:
      del fish_frame[3]</code>. </p>
  
  <p>Right before this command, however, I drop all columns of <code>NaN</code>s. So that removes column <code>[3]</code> because it is filled with <code>NaN</code>s, so it fails. </p>
  
  <p>I would like to say just drop the final column of the entire DataFrame. I feel like that would work perfectly. </p>
  
  <p>I tried <code>fish_frame([:-1], axis=1)</code> but that's invalid syntax.</p>
  
  <p>Any help would be appreciated thanks. </p>
  
  <p>The DataFrame:</p>
  
  <pre><code>fish_frame after dropna:
  
                                0        1      2           4
  0                         #0721      NaN    NaN         NaN
  1                       GBE COD      746  $2.00   $1,492.00
  2                       GBW COD   13,894  $0.50   $6,947.00
  3                       GOM COD       60  $2.00     $120.00
  4            GB WINTER FLOUNDER   94,158  $0.25  $23,539.50
  5           GOM WINTER FLOUNDER    3,030  $0.50   $1,515.00
  6                   GBE HADDOCK   18,479  $0.02     $369.58
  7                   GOM HADDOCK        0  $0.02       $0.00
  8                   GBW HADDOCK  110,470  $0.02   $2,209.40
  9                          HAKE      259  $1.30     $336.70
  10                       PLAICE    3,738  $0.40   $1,495.20
  11                      POLLOCK    3,265  $0.02      $65.30
  12               WITCH FLOUNDER    1,134  $1.30   $1,474.20
  13                       SNE YT    1,458  $0.65     $947.70
  14                        GB YT    4,499  $0.70   $3,149.30
  15                      REDFISH      841  $0.02      $16.82
  16  54 DAS @ $8.00/DAY = 432.00      NaN    NaN        None
  </code></pre>