Functional csv.DictWriter example where columns keep the original order

ordered_dictwriter.py

#!/usr/bin/env python3

# Functional csv.DictWriter example where columns keep the original order

import csv


def gen_rows(input_path):
    with open(input_path) as input_file:
        reader = csv.DictReader(input_file)
        yield reader.fieldnames
        for row in reader:
            yield row


def put_rows(output_path, rows):
    with open(output_path, 'w') as output_file:
        field_names = next(rows)
        writer = csv.DictWriter(output_file, fieldnames=field_names)
        writer.writeheader()
        for row in rows:
            writer.writerow(row)


if __name__ == "__main__":
    put_rows('output.csv', gen_rows('input.csv'))