title: Groupby aggregate and create new columns from row cells
body: <p>I have the following code I'm working with in JuypterNotebook:</p>
  
  <pre><code>import pandas as pd
  import numpy as np
  
      url = 'https://raw.githubusercontent.com/dothemathonthatone/maps/master/fruchtbarkeit.csv'
  fruchtdf = pd.read_csv(url)
  
  
  fruchtdf = fruchtdf.set_axis(['year', 'regional_schlüssel', 'kreis_frei', 'gender', 'nationality', 'u15', '15', '16', '17', '18', '19', '20',
   '21', '22', '23', '24', '25', '26', '27', '28', '29', '30','31', '32', '33', '34', '35', '47', '48', '49', 'Ü5',
   '38', '39', '36', '37', '40', '41', '42', '43', '44', '45', '46', 'uknwn'], axis=1, inplace=False)
  
  fruchtdf['15']= fruchtdf['u15']+fruchtdf['15']
  
  fruchtdf.drop(['u15'], axis=1, inplace=True)
  
  
  
        year  regional_schlüssel  kreis_frei       gender     nationality     15  16  17  18  19  ...     36  37  40  41  42  43  44  45  46  uknwn
  0   2000    5111000     Düsseldorf, krfr. Stadt     man     Deutsche    --1     7   9   20  24  ...     13  1   -   1   1   -   -   -   -   -
  1   2000    5111000     Düsseldorf, krfr. Stadt     man     Ausländerin     ---     3   3   7   17  ...     4   3   1   -   -   -   -   -   1   -
  2   2000    5111000     Düsseldorf, krfr. Stadt     woman   Deutsche    --1     4   7   14  20  ...     9   4   3   2   1   -   -   -   -   -
  3   2000    5111000     Düsseldorf, krfr. Stadt     woman   Ausländerin     ---     1   5   10  17  ...     2   4   1   1   1   -   -   -   -   -
  4   2000    5111000     Düsseldorf, krfr. Stadt     man     Deutsche    --1     9   14  30  45  ...     3   1   -   -   -   -   -   -   -   -
  </code></pre>
  
  <p>I am trying to aggregate columns <code>15</code> to <code>unknown</code> grouping by <code>nationality</code>, <code>year</code>, and <code>regioinal_schlüssel</code> </p>
  
  <p><code>year regional_schlüssel nationality gender 15  16  17 ... unknown 
  2000  5111000             Deutsche    man    1   4   4        7
  2000  5111000             Deutsche  woman    1   4   4        3
  2000  5111000             Auslande    man    1   4   4        7
  2000  5111000             Auslande  woman    1   4   4        3</code></p>
  
  <p>desired output:</p>
  
  <p><code>year regional_schlüssel nationality gender 15  16  17 ... unknown 
  2000  5111000             Deutsche    man    2   8   8        10
  2000  5111000             Auslande    man    2   8   8        10</code></p>
  
  <p>Then I would like to make 2 new sets of columns for each nationality: <code>De15</code>, <code>De16</code>, <code>...</code>, <code>unknown</code>, and <code>Aus15</code>, <code>Aus16</code>, <code>...</code>, <code>Ausunknown</code> </p>
  
  <p><code>year regional_schlüssel nationality gender De15  De16  De17 ... Deunknown Aus15  Aus16  Aus17 Ausunknown 
  2000  5111000             Deutsche    man    2     8     8        10        2      8      8      10</code></p>
  
  <p>Is this possible?</p>