Assets change of buying a apartment in china in tensor?

ten_years.py

import math
import numpy_financial as npf


def get_irr(loan, X, plan_month):
    """Finacial concept"""
    v = [-loan]
    for i in range(plan_month):
        v.append(X)
    return npf.irr(v)


def deng_e_ben_xi(base_loan, month_rate, plan_month, real_month):
    """ pay_list用于标明每期的账单 depst_list[i] 用于标明在第i期还款后剩余的本金,这个值将用于提前还款使用,1.01是由于银行往往会有1%的违约金,可以只计算前real_month期的,也可以全部计算 """
    sum_exp_plan = (1+month_rate)**(plan_month)
    X = base_loan*month_rate*sum_exp_plan/(sum_exp_plan-1)
    irr = get_irr(base_loan, X, plan_month)
    pay_list = []
    dept_list = []
    remain_dept = base_loan
    for i in range(real_month):
        pay_list.append(X)
        remain_dept = remain_dept-(X-remain_dept*irr)
        dept_list.append(remain_dept*1.01)
    return pay_list, dept_list


def deng_e_ben_jin(base_loan, month_rate, plan_month, real_month):
    remain_dept = base_loan
    base_month = base_loan/plan_month
    pay_list = []
    dept_list = []
    for i in range(real_month):
        interest = remain_dept * month_rate
        pay_list.append(interest+base_month)
        remain_dept -= base_month
        dept_list.append(remain_dept*1.01)
    return pay_list, dept_list


def ten_years(house_pirce=160,  # 房屋总价
              curent_money=110,  # 买房时的现金
              avg_gain_month=2.5,  # 预期的月平均收入
              rent_fee=0.22,  # 预期的月平均租金(不买房的话需要租房)
              real_month=12*10,  # 只计算多少期
              plan_month=12*30,  # 分期计划
              first_shot_ratio=0.3,  # 首付比例
              house_inflation_rate = 1.04, # 房屋价格的膨胀系数(每年)
              investigate_rate=0.03 / 12,  # 现金用于理财/投资的月均收益率
              month_rate=0.043 / 12,  # 房贷的月均利率
              pay_list_fn=deng_e_ben_xi):  # 分期方法,默认等额本息

    loan = house_pirce * (1-first_shot_ratio)
    pay_list, dept_list = pay_list_fn(loan, month_rate, plan_month, real_month)

    money_house = curent_money - house_pirce * first_shot_ratio - house_pirce*0.05
    money_no_house = curent_money

    print("{:>2}.{:>2},{:>20},{:>20},{:>20}".format(
        "YY", "MM", "cash_no_house", "cash_house", "asset_house"))
    inflation = house_inflation_rate
    prod_inflation = inflation # 用于评估房子的增值率
    for i in range(len(pay_list)):
        money_house = money_house * \
            (1+investigate_rate) + avg_gain_month - pay_list[i]
        asset_house = money_house - \
            dept_list[i] + house_pirce * prod_inflation
        prod_inflation *= math.pow(house_inflation_rate, 1/12)
        money_no_house = money_no_house * \
            (1+investigate_rate) + avg_gain_month - rent_fee
        print("{:>2}.{:>2},{:>20},{:>20},{:>20}".format(
            round(math.floor(i/12))+1, (i) % 12+1, money_no_house, money_house, asset_house))


ten_years()