csv kram ...

"""
Beschreibung ...
"""

import csv
import sys
from argparse import ArgumentParser, FileType
from datetime import datetime as DateTime
from urllib.request import urlretrieve


def get_demo_data():
    csv_url = "https://opendata.ecdc.europa.eu/covid19/casedistribution/csv"
    file, http_reply = urlretrieve(csv_url)
    return file


def constraints(row):
    """
    Filter nach Fälle > 100
    """
    try:
        return int(row[4]) > 100 and row[6].casefold() == "germany"
    except ValueError:
        return False


def transformer(row):
    """
    Nur Datum, Sterbefälle und Land ausgeben.
    """
    try:
        return [DateTime.strptime(row[0], "%d/%m/%Y").date().isoformat(), row[4], row[6]]
    except ValueError:
        return [row[0], row[4], row[6]]


def main(input_file, output_file):
    with open(input_file, "rt", encoding="utf8", newline="") as fd_in:
        reader = csv.reader(fd_in)
        with open(output_file, "wt", encoding="utf8", newline="") as fd_out:
            writer = csv.writer(fd_out)
            # den header schreibe ich explizit
            # der transformer selektiert spalten
            writer.writerow(transformer(next(reader)))
            for row in reader:
                if constraints(row):
                    row = transformer(row)
                    writer.writerow(row)


def get_args():
    parser = ArgumentParser(__doc__)
    parser.add_argument("input_file", help="CSV Eingabedatei")
    parser.add_argument("output_file", help="CSV Ausgabedatei")
    return parser.parse_args()


if __name__ == "__main__":
    main(get_demo_data(), "output.csv")
#    args = get_args()
#    try:
#        main(**vars(args))
#    except Exception as e:
#        print(repr(e))
#        sys.exit(1)