Simple script to calculate Paypal fee

paypal_fee.py

#!/usr/bin/env python
import sys
from math import ceil


def ceil_two_digits(amount):
    return (ceil(amount * 100) / 100.0)


def calculate_invoice(invoice_amount):
    """ Calculate paypal fee (4.4%) + 0.3 USD"""

    total_amount = 100 * invoice_amount / 95.6
    paypal_fee = total_amount - invoice_amount + 0.3  # there is an additional fee 0.3 USD. 

    # ceil the amount
    paypal_fee = ceil_two_digits(paypal_fee)
    total_amount = ceil_two_digits(invoice_amount + paypal_fee)
    return paypal_fee, total_amount


if __name__ == "__main__":
    """ example: python paypal.py 431.75 """

    if len(sys.argv) < 2:
        print("Please add your invoice amount => 'python paypal.py 431.75' ")
        sys.exit()

    invoice_amount = float(sys.argv[1])

    paypal_fee, total_amount = calculate_invoice(invoice_amount)

    print("Invoice amount: {}".format(invoice_amount))
    print("Paypal Fee: {}".format(paypal_fee))
    print("Total Invoice: {}".format(total_amount))