android_dev android_dev - 2 months ago 12
Python Question

Python/CSV unique rows with unique values per row in a column

Have this dataset, dataset is fictional:

cat sample.csv

id,fname,lname,education,gradyear,attributes
"6F9619FF-8B86-D011-B42D-00C04FC964FF",john,smith,mit,2003,qa
"6F9619FF-8B86-D011-B42D-00C04FC964FF",john,smith,harvard,2007,"test|admin,test"
"6F9619FF-8B86-D011-B42D-00C04FC964FF",john,smith,harvard,2007,"test|admin,test"
"6F9619FF-8B86-D011-B42D-00C04FC964FF",john,smith,ft,2012,NULL
"6F9619FF-8B86-D011-B42D-00C04FC964F1",john,doe,htw,2000,dev


When I run this script, which parses the csv and finds unique rows, concating rows in on column when more are found:

parse-csv.py

import itertools

from itertools import groupby
import csv
import pprint
import argparse

if __name__ == '__main__':
parser = argparse.ArgumentParser(description='sql dump parser')
parser.add_argument('-i','--input', help='input file', required=True)
parser.add_argument('-o','--output', help='output file', required=True)
args = parser.parse_args()
inputf = args.input
outputf = args.output


t = csv.reader(open(inputf, 'rb'))
t = list(t)


def join_rows(rows):
return [(e[0] if i < 1 else '|'.join(e)) for (i, e) in enumerate(zip(*rows))]

myfile = open(outputf, 'wb')
wr = csv.writer(myfile, quoting=csv.QUOTE_ALL, lineterminator='\n')

for name, rows in groupby(t, lambda x:x[0]):
wr.writerow(join_rows(rows))
#print join_rows(rows)


And than another script, which makes sure each colum has only unique values separated by "|"

unique.py

import csv
import sys
from collections import OrderedDict
import argparse

csv.field_size_limit(sys.maxsize)

import argparse

if __name__ == '__main__':
parser = argparse.ArgumentParser(description='sql dump parser - unique')
parser.add_argument('-i','--input', help='input file', required=True)
parser.add_argument('-o','--output', help='output file', required=True)
args = parser.parse_args()
inputf = args.input
outputf = args.output


with open(inputf) as fin, open(outputf, 'wb') as fout:
csvin = csv.DictReader(fin)
csvout = csv.DictWriter(fout, fieldnames=csvin.fieldnames, quoting=csv.QUOTE_ALL,lineterminator='\n')
csvout.writeheader()
for row in csvin:
for k, v in row.items():
row[k] = '|'.join(OrderedDict.fromkeys(v.split('|')))
csvout.writerow(row)


It works for the sample.csv

Output:

$ python parse-csv.py -i sample.csv -o sample-out.csv
$ python unique.py -i sample-out.csv -o sample-final.csv

$ cat sample-final.csv

"id","fname","lname","education","gradyear","attributes"
"6F9619FF-8B86-D011-B42D-00C04FC964FF","john","smith","mit|harvard|ft","2003|2007|2012","qa|test|admin,test|NULL"
"6F9619FF-8B86-D011-B42D-00C04FC964F1","john","doe","htw","2000","dev"


But when I do the same for this:

(dataset is fictional)

sample2.csv

id,lastname,firstname,middlename,address1,address2,city,zipcode,city2,zipcode2,emailaddress,website
"E387F3C1-F6E9-40DD-86AB-A7149C67F61C","Technical Support",NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL
"648EEB5D-0586-444A-B86F-4EB2446BBC93","Palm","Samuel","J",NULL,NULL,NULL,NULL,NULL,NULL,"",NULL
"A94FAD4E-27DB-48FE-B89E-C37B408C5DD5","Mait","A.V.",NULL,NULL,NULL,NULL,NULL,NULL,NULL,"mait@yahoo.com",NULL
"E387F3C1-F6E9-40DD-86AB-A7149C67F61C","Technical Support",NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL
"648EEB5D-0586-444A-B86F-4EB2446BBC93","Palm","Samuel","J",NULL,NULL,NULL,NULL,NULL,NULL,"",NULL
"A94FAD4E-27DB-48FE-B89E-C37B408C5DD5","Mait","A.V.",NULL,NULL,NULL,NULL,NULL,NULL,NULL,"mait@yahoo.com",NULL
"FDFCA22A-EE19-4997-B892-90B2006FE328","Drago","Paul",NULL,"","","","",NULL,NULL,"psd@gmail.com",NULL
"FDFCA22A-EE19-4997-B892-90B2006FE328","Drago","Paul",NULL,"","","","",NULL,NULL,"psd@gmail.com",NULL
"FDFCA22A-EE19-4997-B892-90B2006FE328","Drago","Paul",NULL,"","","","",NULL,NULL,"psd@gmail.com",NULL
"FDFCA22A-EE19-4997-B892-90B2006FE328","Drago","Paul",NULL,"","","","",NULL,NULL,"psd@gmail.com",NULL
"FDFCA22A-EE19-4997-B892-90B2006FE328","Drago","Paul",NULL,"","","","",NULL,NULL,"psd@gmail.com",NULL


The output is:

$ python parse-csv.py -i sample2.csv -o sample2-out.csv
$ python unique.py -i sample2-out.csv -o sample2-final.csv
$ cat sample2-final.csv

"id","lastname","firstname","middlename","address1","address2","city","zipcode","city2","zipcode2","emailaddress","website"
"E387F3C1-F6E9-40DD-86AB-A7149C67F61C","Technical Support","NULL","NULL","NULL","NULL","NULL","NULL","NULL","NULL","NULL","NULL"
"648EEB5D-0586-444A-B86F-4EB2446BBC93","Palm","Samuel","J","NULL","NULL","NULL","NULL","NULL","NULL","","NULL"
"A94FAD4E-27DB-48FE-B89E-C37B408C5DD5","Mait","A.V.","NULL","NULL","NULL","NULL","NULL","NULL","NULL","mait@yahoo.com","NULL"
"E387F3C1-F6E9-40DD-86AB-A7149C67F61C","Technical Support","NULL","NULL","NULL","NULL","NULL","NULL","NULL","NULL","NULL","NULL"
"648EEB5D-0586-444A-B86F-4EB2446BBC93","Palm","Samuel","J","NULL","NULL","NULL","NULL","NULL","NULL","","NULL"
"A94FAD4E-27DB-48FE-B89E-C37B408C5DD5","Mait","A.V.","NULL","NULL","NULL","NULL","NULL","NULL","NULL","mait@yahoo.com","NULL"
"FDFCA22A-EE19-4997-B892-90B2006FE328","Drago","Paul","NULL","","","","","NULL","NULL","psd@gmail.com","NULL"


Why it doesn't properly get unique rows and columns like it did for sample.csv????

Anybody has any ideas?

Thanks in advance! Chewing on this for a long time now ....

Answer

Your first file is sorted, while the second is not. Please see this discussion

All you need is this:

t = list(t)
t[1:] = sorted(t[1:])
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