python 实现一个图形界面的汇率计算器

调用的api接口：

https://api.exchangerate-api.com/v4/latest/USD

完整代码

import requests
from tkinter import *
import tkinter as tk
from tkinter import ttk

class RealTimeCurrencyConverter():
 def __init__(self,url):
     self.data = requests.get(url).json()
     self.currencies = self.data['rates']

def convert(self, from_currency, to_currency, amount):
   initial_amount = amount
   if from_currency != 'USD' :
     amount = amount / self.currencies[from_currency]

amount = round(amount * self.currencies[to_currency], 4)
   return amount

class App(tk.Tk):

def __init__(self, converter):
   tk.Tk.__init__(self)
   self.title = 'Currency Converter'
   self.currency_converter = converter

self.geometry("500x200")

self.intro_label = Label(self, text = 'Welcome to Real Time Currency Convertor', fg = 'blue', relief = tk.RAISED, borderwidth = 3)
   self.intro_label.config(font = ('Courier',15,'bold'))

self.date_label = Label(self, text = f"1 Indian Rupee equals = {self.currency_converter.convert('INR','USD',1)} USD \n Date : {self.currency_converter.data['date']}", relief = tk.GROOVE, borderwidth = 5)

self.intro_label.place(x = 10 , y = 5)
   self.date_label.place(x = 160, y= 50)

valid = (self.register(self.restrictNumberOnly), '％d', '％P')
   self.amount_field = Entry(self,bd = 3, relief = tk.RIDGE, justify = tk.CENTER,validate='key', validatecommand=valid)
   self.converted_amount_field_label = Label(self, text = '', fg = 'black', bg = 'white', relief = tk.RIDGE, justify = tk.CENTER, width = 17, borderwidth = 3)

self.from_currency_variable = StringVar(self)
   self.from_currency_variable.set("INR")
   self.to_currency_variable = StringVar(self)
   self.to_currency_variable.set("USD")

font = ("Courier", 12, "bold")
   self.option_add('*TCombobox*Listbox.font', font)
   self.from_currency_dropdown = ttk.Combobox(self, textvariable=self.from_currency_variable,values=list(self.currency_converter.currencies.keys()), font = font, state = 'readonly', width = 12, justify = tk.CENTER)
   self.to_currency_dropdown = ttk.Combobox(self, textvariable=self.to_currency_variable,values=list(self.currency_converter.currencies.keys()), font = font, state = 'readonly', width = 12, justify = tk.CENTER)

self.from_currency_dropdown.place(x = 30, y= 120)
   self.amount_field.place(x = 36, y = 150)
   self.to_currency_dropdown.place(x = 340, y= 120)

self.converted_amount_field_label.place(x = 346, y = 150)

self.convert_button = Button(self, text = "Convert", fg = "black", command = self.perform)
   self.convert_button.config(font=('Courier', 10, 'bold'))
   self.convert_button.place(x = 225, y = 135)

def perform(self):
   amount = float(self.amount_field.get())
   from_curr = self.from_currency_variable.get()
   to_curr = self.to_currency_variable.get()

converted_amount = self.currency_converter.convert(from_curr,to_curr,amount)
   converted_amount = round(converted_amount, 2)

self.converted_amount_field_label.config(text = str(converted_amount))

def restrictNumberOnly(self, action, string):
   regex = re.compile(r"[0-9,]*?(\.)?[0-9,]*$")
   result = regex.match(string)
   return (string == "" or (string.count('.') <= 1 and result is not None))

if __name__ == '__main__':
 url = 'https://api.exchangerate-api.com/v4/latest/USD'
 converter = RealTimeCurrencyConverter(url)

App(converter)
 mainloop()

运行效果：

来源：https://data-flair.training/blogs/currency-converter-python/