[CentralOH] DoJo Mumbilings for March 28, 2019

[Thomas Winningham]

1. Fixes row 9 to have category 2
2. Creates an EAV "facts" table, sort of like a graph
3. Assumes only one matching value, no aggregate sums, etc
4. Extendable to other similar problems, although report generation is
rather hard coded for this dataset

import uuid

fields = ['id','category','type','value']

data = [
        [1,1,"A",2],
        [2,3,"D",5],
        [3,4,"B",7],
        [4,2,"C",8],
        [5,4,"D",9],
        [6,4,"C",1],
        [7,1,"D",3],
        [8,3,"C",9],
        [9,2,"A",5],
        [10,3,"A",4],
        [11,1,"B",6],
        [12,4,"A",2],
        [13,2,"D",6],
        [14,3,"B",3],
        [15,2,"B",8],
        [16,1,"C",0]
        ]


# Create fact table

facts = []

for x in data:
    this_fact=str(uuid.uuid1())
    for f in range(len(fields)):
        facts.append((this_fact, fields[f], x[f]))

# Create some query functions for EAV structure

E,A,V = 0,1,2

q_e4av = lambda a,v : [x[E] for x in facts if x[A]==a and x[V]==v]
q_v4a  = lambda a   : [x[V] for x in facts if x[A]==a]
q_v4ea = lambda e,a : [x[V] for x in facts if x[E]==e and x[A]==a]

# Generate report

uniq_cats = sorted(list(set(q_v4a('category'))))
uniq_typs = sorted(list(set(q_v4a('type'))))

result=[]
for c in uniq_cats:
    row=[]
    for t in uniq_typs:
       cat_ids = set(q_e4av('category',c))
       typ_ids = set(q_e4av('type',t))
       result_entity = list(cat_ids & typ_ids)
       if len(result_entity) > 0:
           row.append(q_v4ea(result_entity[0],'value')[0])
       else:
           row.append(None)
    result.append(row)

print('\t'+'\t'.join(uniq_typs))
for c in range(len(uniq_cats)):
    print('\t'.join([str(uniq_cats[c])]+[repr(x) for x in result[c]]))

#-----------------------

$ python3 test1.py

        A       B       C       D
1       2       6       0       3
2       5       8       8       6
3       4       3       9       5
4       2       7       1       9




On Thu, Mar 28, 2019 at 3:53 PM Travis Risner <deeppunster at gmail.com> wrote:

> Hi folks,
>
> Here is a problem proposed by one of our own members.  (The problem is
> in the attached PDF.)
>
> Travis
>
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> https://mail.python.org/mailman/listinfo/centraloh
>
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