Comparing income of Beijing and Singapore.

income.py

import sys
import fire

class Beijing:
    max_base = 28221
    min_base = 5360
    def __init__(self, total):
        self.total = total

    def wuxianyijin(self):
        base = max(min(self.max_base, self.total / 12), self.min_base) * 12
        xian = base * (0.08 + 0.005 + 0 + 0.02 + 0)
        jin = base * 0.12
        cost = xian + jin
        return cost, jin

    def tax(self):
        cost, jin = self.wuxianyijin()
        taxable_income = self.total - cost - jin
        return self.do_tax(taxable_income)

    def do_tax(self, money):
        if money <= 60000:
            return 0
        money -= 60000
        if money <= 36000:
            return money * 0.03
        elif money <= 144000:
            return money * 0.1 - 2520
        elif money <= 300000:
            return money * 0.2 - 16920
        elif money <= 420000:
            return money * 0.25 - 31920
        elif money <= 660000:
            return money * 0.3 - 52920
        elif money <= 960000:
            return money * 0.35 - 85920
        else:
            return money * 0.45 - 181920

    def run(self):
        cost, jin = self.wuxianyijin()
        tax = self.tax()
        daoshou = self.total - cost - tax
        jin *= 2
        # return {'total': self.total, 'daoshou': daoshou, 'daoshou+jin': daoshou + jin, 'jin': jin, '5xian': cost, 'tax': tax}
        return {'税前': self.total, '到手': daoshou, '到手+买房钱': daoshou + jin, '公积金': jin, '五险': cost, '个税': tax}

class Singapore:
    conv = 4.778
    def __init__(self, total, num_xin, has_cpf):
        self.total = total / self.conv
        self.num_xin = num_xin
        self.has_cpf = has_cpf
        assert self.num_xin >= 12

    def cpf(self, money):
        ow_ceiling = 6000
        monthly = self.total / self.num_xin
        ow = min(monthly, ow_ceiling)
        total_cpf = ow * 12 * 0.37 + (self.num_xin - 12) * monthly * 0.37
        return total_cpf * (0.2 / 0.37), total_cpf * (0.23 / 0.37)

    def do_tax(self, money):
        '''
        >>> sg = Singapore(4, 14, False)
        >>> round(sg.do_tax(20000))
        0
        >>> round(sg.do_tax(10000))
        0
        >>> round(sg.do_tax(30000))
        200
        >>> round(sg.do_tax(40000))
        550
        >>> round(sg.do_tax(50000))
        1250
        >>> round(sg.do_tax(80000))
        3350
        >>> round(sg.do_tax(120000))
        7950
        '''
        total_tax = 0
        steps = [20000, 10000, 10000, 40000, 40000, 40000, 40000, 40000, 40000, 40000, 99999999999]
        rates = [0., 0.02, 0.035, 0.07, 0.115, 0.15, 0.18, 0.19, 0.195, 0.20, 0.22]
        for step, next_step, rate in zip(steps[:-1], steps[1:], rates):
            if money >= step:
                total_tax += step * rate
                money -= step
            else:
                break
        return total_tax + money * rate

    def _run(self):
        taxable_income = self.total
        if self.has_cpf:
            paied_jin, got_jin = self.cpf(self.total)
            taxable_income -= paied_jin
        else:
            paied_jin, got_jin = 0., 0.
        tax = self.do_tax(taxable_income)
        daoshou = self.total - tax - paied_jin
        # return {'total': self.total, 'daoshou': daoshou, 'daoshou+jin': daoshou + got_jin, 'tax': tax, 'jin': paied_jin, '5xian': got_jin / 0.23 * 0.14}
        return {'税前': self.total, '到手': daoshou, '到手+买房钱': daoshou + got_jin, '个税': tax, '交的CPF': paied_jin, '非买房CPF': got_jin / 0.23 * 0.14}

    def run(self):
        return {k: v * self.conv for k, v in self._run().items()}

def main(total: int, place: str, num_xin: int = 14, has_cpf: bool = False):
    table = {'bj': Beijing(total), 'sg': Singapore(total, num_xin, has_cpf)}
    print(table[place].run())

'''
$ python income.py --total=481622.39999999997 --place=bj
{'税前': 481622.39999999997, '到手': 361148.83499999996, '到手+买房钱': 442425.31499999994, '公积金': 81276.48, '五险': 76196.70000000001, '个税': 44276.86499999999}
$ python income.py --total=481622.39999999997 --place=sg
{'税前': 481622.39999999997, '到手': 454187.12399999995, '到手+买房钱': 454187.12399999995, '个税': 27435.275999999998, '交的CPF': 0.0, '非买房CPF': 0.0}
$ python income.py --total=481622.39999999997 --place=sg --has_cpf
{'税前': 481622.39999999997, '到手': 381118.12559999997, '到手+买房钱': 476066.54159999994, '个税': 17940.434400000002, '交的CPF': 82563.84, '非买房CPF': 57794.688}
'''
if __name__ == '__main__':
    import doctest
    doctest.testmod()

    fire.Fire(main)