In this tutorial, we’ll build a fun and practical Python project – a Currency Converter. We'll use the tkinter library to create a simple user interface.

Currency Converter in Python

Prerequisites

To work on this Python currency converter project, you should know basic Python and how to work with external libraries.

tkinter – for building the User Interface (UI)

requests – for accessing real-time exchange rate data from an API

To install the libraries, use the following commands in your terminal:

bash

pip install tkinter pip install requests

Steps to Build the Python Currency Converter Project

1. Real-time Exchange Rates

We'll use real-time exchange data from a public API. This API returns JSON data that includes:

Base – Usually in USD (US Dollar)

Date and Time – Shows when the data was last updated

Rates – Shows currency rates compared to the base currency

2. Import Required Libraries

python

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

3. Create the CurrencyConverter Class

3.1 Constructor

python

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

This loads JSON data from the API and stores currency rates.

3.2 Convert Method

python

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

This method converts one currency to another using USD as a base.

Example:

python

url = 'https://api.exchangerate-api.com/v4/latest/USD' converter = RealTimeCurrencyConverter(url) print(converter.convert('INR','USD',100))

Output:

1.33

4. Build the User Interface (UI)

We’ll use tkinter to create a graphical interface.

4.1 Initialize the UI

python

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

This initializes the UI window.

4.2 Add Labels and Info

python

self.geometry("500x200") self.intro_label = Label(self, text='Welcome to Real Time Currency Converter', fg='blue', relief=tk.RAISED, borderwidth=3) self.intro_label.config(font=('Courier', 15, 'bold')) self.date_label = Label(self, text=f"1 INR = {self.currency_converter.convert('INR','USD',1)} USD \nDate: {self.currency_converter.data['date']}", relief=tk.GROOVE, borderwidth=5) self.intro_label.place(x=10, y=5) self.date_label.place(x=170, y=50)

4.3 Add Entry and Dropdowns

python

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)

4.4 Add Convert Button

python

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)

5. Create the perform() Method

python

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))

6. Restrict Non-numeric Input

python

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))

7. Create the Main Function

python

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

Summary

In this project, we learned how to build a real-time currency converter using Python. We used tkinter for the interface and an API for fetching current exchange rates. This kind of project helps in improving both your Python programming and UI development skills.