房贷计算器python源码.zip

#!/usr/bin/env python ################################################################################################### # # Title: bank_loan_calculator.py # Usage: To make a calculation for the bank loan # Author: Wi1s0n # Date: 2021/09/15 # ################################################################################################### import prettytable as pt class LoanCalculation(object): """ [住房贷款计算器] 1、支持等额本息、等额本金两种计算方式； 2、还款周期以月为单位，输出当前期数、月供总额、月供本金、月供利息、剩余本金； 3、交互式菜单输入，并以表格形式显示结果，增加可读性。 """ def __init__(self): """ @param installment_list: 月供清单 @param total_payment: 还款总额 @param total_interest: 利息总额 """ self.installment_list = [] self.total_payment = 0 self.total_interest = 0 def equal_interest(self,P,R,N): """等额本息""" Pi = P A = (P*R/1200*(1+R/1200)**N)/((1+R/1200)**N-1) for i in range(1,N+1): B = (P*R/1200*(1+R/1200)**(i-1))/((1+R/1200)**N-1) r = A-B Pi -= B installment_dict = {"time_num":i, "monthly_payment":round(A,2), "monthly_principal":round(B,2), "monthly_interest":round(r,2), "rest_loan":round(Pi,2)} self.installment_list.append(installment_dict) self.total_payment = (round(sum([x["monthly_payment"] for x in self.installment_list]))) self.total_interest = (round(sum([x["monthly_interest"] for x in self.installment_list]))) def equal_principal(self,P,R,N): """等额本金""" B = P/N for i in range(1,N+1): A = P/N+(P-P/N*(i-1))*R/1200 r = A-B installment_dict = {"time_num":i, "monthly_payment":round(A,2), "monthly_principal":round(B,2), "monthly_interest":round(r,2), "rest_loan":round(P-P/N*i,2)} self.installment_list.append(installment_dict) self.total_payment = (round(sum([x["monthly_payment"] for x in self.installment_list]))) self.total_interest = (round(sum([x["monthly_interest"] for x in self.installment_list]))) def standardized_output(self): """输出表格""" tb = pt.PrettyTable() tb.field_names = list(self.installment_list[0].keys()) for i in self.installment_list: tb.add_row(list(i.values())) self.installment_list.clear() # 清空列表 return tb @staticmethod def print_menu(): """程序菜单提示""" main_menu = pt.PrettyTable() main_menu.field_names = ["The Bank Loan Calculator V1.0"] main_menu.add_row(["[1] Equality principal and interest"+" "*18]) main_menu.add_row(["[2] Equality principal"+" "*32]) main_menu.add_row(["[0] quit"+" "*46]) main_menu.junction_char = "#" main_menu.horizontal_char = "*" main_menu.vertical_char = "|" return main_menu @staticmethod def option_info(opcode,P,R,N): """用户选项信息""" user_scheme_info = pt.PrettyTable() user_scheme_info.field_names = ["Loan scheme","Principal (RMB)","Annual interest rate (%)","Loan time (month)"] if opcode == 1: user_scheme_info.add_row(["Equality principal&interest",P,R,N]) else: user_scheme_info.add_row(["Equality principal",P,R,N]) return user_scheme_info def show_calculation(self,opcode,P,R,N): """计算结果显示""" print("Your loan scheme details is as follow:") print(self.option_info(opcode,P,R,N)) if opcode == 1: self.equal_interest(P,R,N) print(self.standardized_output()) print("Total Payment:{},Total Interest:{}".format(self.total_payment,self.total_interest)) else: self.equal_principal(P,R,N) print(self.standardized_output()) print("Total Payment:{},Total Interest:{}".format(self.total_payment,self.total_interest)) def input_control(self): """用户输入控制""" while True: try: print(self.print_menu()) opcode = int(input("Please input the option you want:")) if opcode in [0,1,2]: if opcode == 0: return P = float(input("Please input the principal:")) R = float(input("Please input the annual interest rate (%):")) N = int(input("Please input the loan time (month):")) else: print("[Warning] Invalid value,motherfucker!Please re-type your information.") continue except ValueError: print("[Warning] Invalid value,motherfucker!Please re-type your information.") continue self.show_calculation(opcode,P,R,N) if __name__ == '__main__': wilson = LoanCalculation() wilson.input_control() print("Goodbye,gentlemen！")