[Tutor] Create a pivot table

[Peter Otten]

jarod_v6--- via Tutor wrote:

> Dear All!
> This is my data from a file.  I want to obtain a count table how many
> times c11 are present for each project and Samples and  Program.
> 
> ['Program', 'Sample', 'Featurename', 'Project'],
>  ['A', 'A100', 'c11', 'post50'],
>  ['A', 'A100', 'c12', 'post50'],
>  ['A', 'A100', 'c14', 'post50'],
>  ['A', 'A100', 'c67', 'post50'],
>  ['A', 'A100', 'c76', 'post50'],
>  ['B', 'A100', 'c11', 'post50'],
>  ['B', 'A100', 'c99', 'post50'],
>  ['B', 'D33', 'c33', 'post50'],
>  ['B', 'D33', 'c31', 'post50'],
>  ['C', 'D34', 'c32', 'post60'],
>  ['C', 'D35', 'c33', 'post60'],
>  ['C', 'D36', 'c11', 'post60'],
>  ['C', 'D37', 'c45', 'post60'],
>  ['C', 'D38', 'c36', 'post60'],
>  ['C', 'D39', 'c37', 'post60']
> I want to obtain pivot table with samples on columns and  program as rown
> and the values I want fusionwhat it is the best way to do this?thanks in
> advance!

With the pivot() function from 

https://mail.python.org/pipermail/tutor/2016-April/108671.html

>>> rows = [
...  ['A', 'A100', 'c11', 'post50'],
...  ['A', 'A100', 'c12', 'post50'],
...  ['A', 'A100', 'c14', 'post50'],
...  ['A', 'A100', 'c67', 'post50'],
...  ['A', 'A100', 'c76', 'post50'],
...  ['B', 'A100', 'c11', 'post50'],
...  ['B', 'A100', 'c99', 'post50'],
...  ['B', 'D33', 'c33', 'post50'],
...  ['B', 'D33', 'c31', 'post50'],
...  ['C', 'D34', 'c32', 'post60'],
...  ['C', 'D35', 'c33', 'post60'],
...  ['C', 'D36', 'c11', 'post60'],
...  ['C', 'D37', 'c45', 'post60'],
...  ['C', 'D38', 'c36', 'post60'],
...  ['C', 'D39', 'c37', 'post60']
... ]
>>> table = pivot(rows, operator.itemgetter(1), operator.itemgetter(0), 
lambda r: r[2] == "c11")
>>> csv.writer(sys.stdout, delimiter="\t").writerows(table)
        A100    D33     D34     D35     D36     D37     D38     D39
A       1       -/-     -/-     -/-     -/-     -/-     -/-     -/-
B       1       0       -/-     -/-     -/-     -/-     -/-     -/-
C       -/-     -/-     0       0       1       0       0       0

There are probably many other options, but you should seriously consider 
using a spreadsheet application.