stock_profit_calculator.py

# Copyright (c) 2020, Kai Wolf. All rights reserved.

from argparse import ArgumentParser

capital_gains_tax = 0.26375

def calculate_profit(quantity, buy_price, sell_price):
    gain = quantity * sell_price - quantity * buy_price
    fees = min(69.9, 4.9 + sell_price * 0.25) # ING-DiBBa order provision
    taxes = (gain - fees) * capital_gains_tax
    return gain - fees - taxes # profit

if __name__ == "__main__":
    parser = ArgumentParser(description='stock profit calculator')
    parser.add_argument('-b', '--buy_price', type=float, help="Buy price", required=True)
    parser.add_argument('-s', '--sell_price', type=float, help="Sell price", required=True)
    parser.add_argument('-q', '--quantity', type=int, help="Number of stocks", required=True)
    args = parser.parse_args()
    print(calculate_profit(args.quantity, args.buy_price, args.sell_price))