Python: CSV challenge (https://gist.github.com/jorinvo/2e43ffa981a97bc17259)

csv_challenge.py

import requests
import datetime

URI = 'https://gist.githubusercontent.com/jorin-vogel/7f19ce95a9a842956358/raw/e319340c2f6691f9cc8d8cc57ed532b5093e3619/data.json'
filename = datetime.date.today().strftime('%Y%m%d.csv')


def imperative():
    with open(filename, 'w') as f:
        f.write('Name,Credit Card\n')
        for customer in requests.get(URI).json():
            if customer['creditcard']:
                f.write('%(name)s,%(creditcard)s\n' % customer)


def functional():
    json_data = requests.get(URI).json()
    affected_customers = (cust for cust in json_data if cust['creditcard'])
    csv_lines = ('%(name)s,%(creditcard)s' % cust for cust in affected_customers)

    with open(filename, 'w') as f:
        f.write('Name,Credit Card\n')
        f.write('\n'.join(csv_lines))


def even_more_functional():
    json_data = requests.get(URI).json()
    affected_customers = filter(lambda cust: cust['creditcard'], json_data)
    csv_lines = ('%(name)s,%(creditcard)s' % cust for cust in affected_customers)

    with open(filename, 'w') as f:
        f.write('Name,Credit Card\n')
        f.write('\n'.join(csv_lines))