hackathon_test.py

import sys
import datetime
from random import randint
import re


def random_with_n_digits(n):
    range_start = 10**(n-1)
    range_end = (10**n)-1
    return randint(range_start, range_end)

year_of_change = 1954

if len(sys.argv) > 1:
    # Validate
    errors = []
    input_data = sys.argv[1]

    if not re.match(r'^\s*(\d){6}[ /]*(\d){3,4}\s*$', input_data):
        raise ValueError("Invalid format, aborting")

    year = int(input_data[0:2])
    month = int(input_data[2:4])
    day = int(input_data[4:6])
    numeric_input = int(input_data.replace('/', ''))

    if month > 12:
        month = month - 50
        if month < 1 or month > 12:
            errors.append('Invalid month')

    if numeric_input % 11 != 0:
        errors.append("Invalid checksum")

    if errors:
        print('INVALID INPUT:')
        for error in errors:
            print(error)
else:
    # Generate
    # Get Date
    date = ''
    valid = False
    while not valid:
        date_text = input('Day of the birth [YYYY-MM-DD]:')
        try:
            date = datetime.datetime.strptime(date_text, '%Y-%m-%d')
            valid = True
        except ValueError:
            print("Invalid date, try again\n")

    # Get Sex
    sex = ''
    valid = False
    while not valid:
        sex = input('Sex [M/F]:')
        if sex in ['M', 'F']:
            valid = True
        else:
            print("Invalid choice, try again\n")

    month = date.month
    if sex == 'F':
        month += 50

    year = int(date.year)

    if year >= year_of_change:
        n = 4
        total_n = 10
    else:
        n = 3
        total_n = 9
    random_number = random_with_n_digits(n)
    print('%02d' % (date.year % 100))
    generated = int('%02d' % (date.year % 100) + '%02d' % month + '%02d' % date.day + str(random_number))

    remain = generated % 11
    if remain > 0:
        generated -= remain

    # Leading zero might be missing
    generated = ('%0' + str(total_n) + 'd') % generated

    print(str(generated)[0:6] + '/' + str(generated)[6:])