python 3.x - Compare 2 csv files using Pandas

Question

How can i compare 2 csv files using Pandas?

File1:

1
2
3
4
5
5
6

File2:

4
5
6
1

Expected result in another file:

2
3

question from:https://stackoverflow.com/questions/65906472/compare-2-csv-files-using-pandas

Answer 1

You can use this method to calculate the differences between the different csv files. Remember to change the file names to the name of your file. Try this:

with open('old.csv', 'r') as t1, open('new.csv', 'r') as t2:
    fileone = t1.readlines()
    filetwo = t2.readlines()

with open('update.csv', 'w') as outFile:
    for line in filetwo:
        if line not in fileone:
            outFile.write(line)

You could also use a more complex method using sets:

#!/usr/bin/env python3

import sys
import argparse
import csv


def get_dataset(f):
    return set(map(tuple, csv.reader(f)))


def main(f1, f2, outfile, sorting_column):
    set1 = get_dataset(f1)
    set2 = get_dataset(f2)
    different = set1 ^ set2

    output = csv.writer(outfile)

    for row in sorted(different, key=lambda x: x[sorting_column], reverse=True):
        output.writerow(row)


if __name__ == '__main__':
    parser = argparse.ArgumentParser()

    parser.add_argument('infile', nargs=2, type=argparse.FileType('r'))
    parser.add_argument('outfile', nargs='?', type=argparse.FileType('w'), default=sys.stdout)
    parser.add_argument('-sc', '--sorting-column', nargs='?', type=int, default=0)

    args = parser.parse_args()

    main(*args.infile, args.outfile, args.sorting_column)