Student Loan Abroad payment plan 1

slc_abroad_plan1.py

import argparse

countries = {
    'belgium': {'currency': 'EUR', 'rate': 0.869943, 'threshold': 24990, 'default': 390},
    'france': {'currency': 'EUR', 'rate': 0.869943, 'threshold': 19995, 'default': 312},
}


def plan1(annual_salary_in_currency: float, country: str) -> float:
    data = countries.get(country)
    salary_in_gbp = annual_salary_in_currency*data.get('rate')
    threshold_in_gbp = data.get('threshold')
    monthly_payment = max(0, (salary_in_gbp - threshold_in_gbp)*0.09/12)
    return monthly_payment/data.get('rate')

def inverse_plan1(monthly_payment_in_currency: float, country: str) -> float:
    data = countries.get(country)
    annual_payment_in_gbp = monthly_payment_in_currency*12*data.get('rate')
    threshold_in_gbp = data.get('threshold')
    salary_in_gbp = threshold_in_gbp + (annual_payment_in_gbp/0.09)
    return salary_in_gbp/data.get('rate')


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('salary')
    parser.add_argument('-c', '--country', default='france')
    args = parser.parse_args()

    s = float(args.salary)
    c = args.country
    d = countries.get(c)
    dp = d.get('default')/d.get('rate')
    print(f"{c}: {plan1(s, c)} EUR / month")
    print(f"Default payment is equivalent to salary of {inverse_plan1(dp, c)} EUR / year")

if __name__ == '__main__':
    main()