Question

我一直在写这个程序，目的是在钱箱里加钱。当我开始乘法时，我意识到我需要对代码进行更改。 int(1) * float(0.05)给了我0.050000000000000003。我尝试搜索如何对其进行四舍五入，但发现float不能准确表示货币，我还发现了有关decimal和quatitize ()的信息。我试图了解如何将其合并到我的代码中，但我一直在努力。如何在我的代码中准确表示货币？

money = {'nickles' : 0, 'dimes' : 0, 'quarters': 0, 'ones': 0, 'twos': 0, 'tens' : 0, 'twenties' : 0, 'fifties': 0, 'one hundreds' : 0}

def display_values():
    print(money['nickles'], 'nickles = ', money['nickles'] * 0.05, 'cents')

def assign_all_values():
    input_nickles()
    input_dimes()
    input_quarters()
    input_ones()
    input_twos()
    input_fives()
    input_tens()
    input_fifties()
    input_one_hundreds()

def input_nickles():    
    money['nickles'] = float(input('how many nickels are in your cash box? '))
    display_values()

def input_dimes():
    money['Dimes'] = float(input('how many dimes are in your cash box? '))
    display_values()

def input_quarters():
    money['Quarters'] = float(input('how many quarters are in your cash box? '))
    display_values()

def input_ones():
    money['Ones'] = int(input('how many one dollar coins are in your cash box? '))
    display_values()

def input_twos():
    money['twos'] = int(input('how many one two dollar coins are in your cash box? '))
    display_values()

def input_fives():
    money['fives'] = int(input('how many five dollar bills are in your cash box? '))
    display_values()

def input_tens():
    money['Tens'] = int(input('how many ten dollar bills are in your cash box? '))
    display_values()

def input_twenties():
    money['Twenties'] = int(input('how many twenty dollar bills are in your cash box? '))
    display_values()

def input_fifties():
    money['fifties'] = int(input('how many fifty dollar bills are in your cash box? '))
    display_values()

def input_one_hundreds():
    money['one hundreds'] = int(input('how many one hundred dollar bills are in your cash box '))
    display_values()

def change_value():
    entry = input("what value would you like to change?\n1. One dollar")

assign_all_values()

Answer 1

您在decimal数据类型的正确轨道上。您可以使用小数代替整数和浮点数将其集成到程序中。

首先，导入模块
from decimal import Decimal as D

然后您可以像这样使用它：
money['nickles'] = D(input('how many nickels are in your cash box? '))

您还应该将乘法因子和起始0定义为十进制。然后，您可以像本机python类型一样执行算术运算（在两个十进制值之间）。
请注意，您应将字符串传递给十进制初始化（例如number = D('0.05')）以获取精确表示

要打印值时，可以使用.quantize(D('1.000'))舍入到＃0的小数位

我怎样才能准确地表示货币

1 个答案: