title: Custom sorting of df
body: <p>I have the following df with sector, equity and a value (MV) for each. In the lines where there only is a sector and no information under equity (like index 0 and 2), this is the sum of MV for the stocks which falls under this sector.</p>
  <pre><code>data = {'Sector':['Automobiles &amp; Components','Automobiles &amp; Components', 'Banks',  'Banks', 'Banks', 'Banks', 'Banks', 'Consumer Services', 'Consumer Services','Consumer Services', 'Materials' ,'Materials', 'Materials', 'Media &amp; Entertainment', 'Media &amp; Entertainment','Media &amp; Entertainment', 'Retailing', 'Retailing', 'Transportation','Transportation'],
      'Equity':['','Autoliv Inc','', 'Nordea Bank Abp', 'Skandinaviska Enskilda Banken', 'Svenska Handelsbanken AB', 'Swedbank AB','','AcadeMedia AB','Evolution Gaming Group AB', '','Boliden AB', 'Svenska Cellulosa AB SCA', '', 'Modern Times Group MTG AB', 'Nordic Entertainment Group AB', '', 'H &amp; M Hennes &amp; Mauritz AB', '', 'Dfds A/S'],
      'MV': [2.345452e+07, 2.345452e+07, 8.112513e+07, 2.044148e+07,3.360675e+07,0,2.707689e+07,3.185811e+07,4.631995e+06,2.722611e+07,1.970195e+07,1.970195e+07,0,1.394064e+07,1.328866e+07,6.519856e+05,0,0,3.913005e+06,3.913005e+06]}
  
  
  df = pd.DataFrame(data)
  
  #Replace the sector with '' when it is a stock
  df.loc[(df['Equity'] != '', 'Sector')] = ''
  
  Index         Sector                         Equity          MV
  0   Automobiles &amp; Components                                 23454520.0
  1                                               Autoliv Inc  23454520.0
  2                      Banks                                 81125130.0
  3                                           Nordea Bank Abp  20441480.0
  4                             Skandinaviska Enskilda Banken  33606750.0
  5                                  Svenska Handelsbanken AB         0.0
  6                                               Swedbank AB  27076890.0
  7          Consumer Services                                 31858110.0
  8                                             AcadeMedia AB   4631995.0
  9                                 Evolution Gaming Group AB  27226110.0
  10                 Materials                                 19701950.0
  11                                               Boliden AB  19701950.0
  12                                 Svenska Cellulosa AB SCA         0.0
  13     Media &amp; Entertainment                                 13940640.0
  14                                Modern Times Group MTG AB  13288660.0
  15                            Nordic Entertainment Group AB    651985.6
  16                 Retailing                                        0.0
  17                                H &amp; M Hennes &amp; Mauritz AB         0.0
  18            Transportation                                  3913005.0
  19                                                 Dfds A/S   3913005.0
  </code></pre>
  <p>Right now, the df is sorted alphabetically according to the sector and then with the stocks in the particular sector beneath it.</p>
  <p>However, I would like to have it sorted by sector according to the MV value in descending order and the same within each sector like a Pivot in Excel. Such that the outcome is instead become</p>
  <pre><code>Index         Sector                         Equity          MV
  0                      Banks                                 81125130.0
  1                             Skandinaviska Enskilda Banken  33606750.0
  2                                                  Swedbank  27076890.0
  3                                           Nordea Bank Abp  20441480.0
  4                                  Svenska Handelsbanken AB         0.0
  5          Consumer Services                                 31858110.0
  6                                  Evolution Gaming Group A  27226110.0
  7                                             AcadeMedia AB   4631995.0
  8   Automobiles &amp; Components                                 23454520.0
  9                                               Autoliv Inc  23454520.0
  10                 Materials                                 19701950.0
  11                                               Boliden AB  19701950.0
  12                                 Svenska Cellulosa AB SCA         0.0
  13     Media &amp; Entertainment                                 13940640.0
  14                                Modern Times Group MTG AB  13288660.0
  15                            Nordic Entertainment Group AB    651985.6
  16                 Retailing                                        0.0
  17                                H &amp; M Hennes &amp; Mauritz AB         0.0
  18            Transportation                                  3913005.0
  19                                                 Dfds A/S   3913005.5
  </code></pre>
  <p>I can't really figure out how to do this while also preserving the order of the totalsum for the sector and then the stocks in the sector.</p>