title: remove specific characters in dataframe and csv file
body: <p>l have a csv file that l treat using pandas dataframe.
  in the column which called <code>left</code> l'm supposed to have only numbers
  1)</p>
  
  <pre><code>  df.icol(4) 
      0       2492
      1       2448
      2       2410
      3       2382
      4       2358
      5       2310
      6       2260
      7       2208
      8       2166
      9       2134
      10       198
      11       198
      12       239
      13       239
      14       243
      15       241
      16       239
      17       394
      18       396
      19       396
      20       396
      21       396
      22       396
      23       396
      24       396
  Name: bottom, dtype: object
  </code></pre>
  
  <p>however going further in my csv file l noticed that l have something like 396] or [456. My question is how l remove all the [ and ] in this column.
  2)
  in the another column</p>
  
  <pre><code>df1.icol(0)
  0       'm'
  1       'i'
  2       'i'
  3       'l'
  4       'm'
  5       'u'
  6       'i'
  7       'l'
  8       'i'
  9       'l'
  10      '.'
  11      '3'
  12      'A'
  13      'M'
  14      'S'
  15      'U'
  16      'N'
  17      'A'
  18      'D'
  19      'R'
  20      'E'
  21      'S'
  22      'S'
  23      'E'
  Name: char, dtype: object
  </code></pre>
  
  <p>l noticed also that l have some rows with <code>['E'</code> , <code>]'S'</code> rather than <code>'E'</code> and <code>'S'</code>.
  how can l remove <code>[</code> and <code>]</code> ?</p>
  
  <p>3) l have a dataframe  </p>
  
  <pre><code>df =[['c', 88, 118, 2872, 2902], [] ,['g', 8, 98, 287, 202]]
  </code></pre>
  
  <p>l want to remove all the <code>'[]'</code>
  as a result l'm looking for something like the following :</p>
  
  <pre><code>df= [['c', 88, 118, 2872, 2902], ['g', 8, 98, 287, 202]]
  </code></pre>