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import argparse |
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import bisect |
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from typing import Any |
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cumulative_deposit_config = { |
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"grossinterest": 2.6, |
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"deduction": 3.5 + 1.5, |
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} |
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individual_monthly_config = { |
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"grossinterestmap": { |
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18: 2.5, |
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24: 2.5, |
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36: 2.5, |
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48: 2.5, |
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60: 2.5, |
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72: 2.75, |
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84: 2.75, |
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96: 3.0, |
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108: 3.0, |
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120: 3.0, |
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132: 3.0, |
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144: 3.0, |
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156: 3.0, |
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168: 3.0, |
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180: 3.0, |
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192: 4.0, |
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204: 6.0, |
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216: 6.0 |
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}, |
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"deduction": 12.5, |
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} |
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def compounding( |
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deposit: float, netinterest: float, maxyears: int, instalment: float = 0.0 |
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) -> float: |
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"""compounding interest effect""" |
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for _ in range(maxyears): |
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deposit += instalment |
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deposit *= (1 + netinterest / 100) |
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return deposit |
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def smallest_number_greater_or_equal(sequence: list[int], number: int) -> int: |
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"""finds the smallest number in a sequence that is greater than or equal to a number""" |
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index = bisect.bisect_left(sequence, number) |
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if index < len(sequence): |
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return sequence[index] |
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message = f"sequence has no number greater than or equal to {number}" |
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raise ValueError(message) |
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def cumulative_deposit( |
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instalment: float, maxyears: int, grossinterest: float, deduction: float |
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) -> float: |
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"""PostaFuturo da Grande deposit policy""" |
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assert 0 < maxyears, "deposit policy must last more than 0 years" |
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if instalment * 12 > 6000: |
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message = "instalment exceeds annual limit of 6000 €" |
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raise ValueError(message) |
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maxyears = min(maxyears, 10) |
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netinterest = grossinterest * (1 - deduction / 100) |
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deposit = instalment * 12 * maxyears |
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balance = compounding(deposit, netinterest, maxyears) |
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return balance |
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def individual_monthly_savings( |
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instalment: float, |
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maxyears: int, |
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grossinterestmap: dict[int, float], |
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deduction: float |
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) -> float: |
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"""Piccoli e Buoni savings plan""" |
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assert 0 < maxyears, "savings plan must last more than 0 years" |
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netinterestmap = { |
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key: value * (1 - deduction / 100) for key, value in grossinterestmap.items() |
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} |
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netinterestseq = sorted(netinterestmap.keys()) |
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endmonth = 18 * 12 |
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maxmonth = min(maxyears * 12, endmonth - 18) |
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balance = 0 |
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for month in range(1, maxmonth): |
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month = endmonth - month + 1 |
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month = smallest_number_greater_or_equal(netinterestseq, month) |
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netinterest = netinterestmap[month] |
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balance += compounding(instalment, netinterest, month // 12) |
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return balance |
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def commandline() -> dict[str, Any]: |
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parser = argparse.ArgumentParser() |
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parser.add_argument( |
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'--instalment', |
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type=float, |
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default=50.0, |
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help="fixed monthly deposit amount" |
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) |
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parser.add_argument( |
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'--cumulative-deposit-maxyears', |
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type=int, |
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default=10, |
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help="max duration of cumulative deposit" |
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) |
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parser.add_argument( |
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'--individual-monthly-maxyears', |
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type=int, |
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default=8, |
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help="max duration of individual monthly savings" |
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) |
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args, _ = parser.parse_known_args() |
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args = vars(args) |
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return args |
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def main( |
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instalment: float, |
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cumulative_deposit_maxyears: int, |
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individual_monthly_maxyears: int |
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): |
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balance = cumulative_deposit( |
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instalment, cumulative_deposit_maxyears, **cumulative_deposit_config |
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) |
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print("cumulative deposit", balance) |
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balance = individual_monthly_savings( |
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instalment, individual_monthly_maxyears, **individual_monthly_config |
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) |
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print("individual monthly", balance) |
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if __name__ == "__main__": |
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args = commandline() |
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main(**args) |
