Currency Converter (Code) in Python

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Currency Converter in Python

About the project: Creating a Python project for a currency converter.

This program will convert an amount from one currency to another using a simple, predefined set of exchange rates.

It will be a console-based application that allows you to choose the currencies and enter the amount you want to convert.

This program uses a dictionary to store a set of predefined exchange rates. You can easily add more currencies and update the rates as needed to keep the converter current.

How to use this Currency Converter:

• Run the Python script.
• The program will display a list of available currencies.
• It will then prompt you to enter the currency to convert from, the currency to convert to, and the amount.
• The script will perform the calculation and display the converted amount.
• You can type q at the currency input prompt to quit the program.

Project Level: Beginner

You can directly copy the below snippet code with the help of green copy button, paste it and run it in any Python editor you have.

Steps: Follow these steps

Step 1: Copy below code using green 'copy' button.

Step 2: Paste the code on your chosen editor.

Step 3: Save the code with filename and .py extention.

Step 4: Run (Press F5 if using python IDLE)

# currency_converter.py

def get_numeric_input(prompt, min_value=0):
    """
    Helper function to get a valid positive numeric input from the user.
    """
    while True:
        try:
            value = float(input(prompt).strip())
            if value <= min_value:
                print("Please enter a positive value.")
            else:
                return value
        except ValueError:
            print("Invalid input. Please enter a number.")

def convert_currency(amount, from_currency, to_currency, rates):
    """
    Converts an amount from a source currency to a target currency.
    """
    if from_currency == to_currency:
        return amount
    
    # Check if currencies are in the rate dictionary
    if from_currency not in rates or to_currency not in rates:
        return None
    
    # Convert to a base currency (e.g., USD) first, then to the target currency.
    # This makes the conversion logic simpler and more scalable.
    amount_in_usd = amount / rates[from_currency]
    converted_amount = amount_in_usd * rates[to_currency]
    
    return converted_amount

def main():
    """
    Main function to run the Currency Converter.
    """
    print("--- Python Currency Converter ---")

    # Define a dictionary of exchange rates relative to a base currency (e.g., USD)
    # You can update these values to reflect current rates.
    exchange_rates = {
        "usd": 1.0,   # US Dollar (base)
        "eur": 0.93,  # Euro
        "gbp": 0.81,  # British Pound
        "jpy": 156.45,  # Japanese Yen
        "cad": 1.37,  # Canadian Dollar
        "aud": 1.51,  # Australian Dollar
        "inr": 83.39  # Indian Rupee
    }

    # Print a list of available currencies
    print("\nAvailable currencies:")
    for currency in exchange_rates.keys():
        print(f"- {currency.upper()}")

    while True:
        # Get user input for currencies and amount
        from_currency = input("\nConvert from currency (e.g., USD): ").strip().lower()
        if from_currency == 'q':
            print("Exiting Currency Converter. Goodbye!")
            break
        
        if from_currency not in exchange_rates:
            print("Invalid source currency. Please choose from the available list.")
            continue
            
        to_currency = input("Convert to currency (e.g., EUR): ").strip().lower()
        if to_currency not in exchange_rates:
            print("Invalid target currency. Please choose from the available list.")
            continue
            
        amount = get_numeric_input(f"Enter amount in {from_currency.upper()}: ")

        # Perform the conversion
        converted_amount = convert_currency(amount, from_currency, to_currency, exchange_rates)

        if converted_amount is not None:
            print(f"\n{amount:.2f} {from_currency.upper()} is equal to {converted_amount:.2f} {to_currency.upper()}.")
        else:
            print("Conversion failed. Please check your currency inputs.")
        
# This ensures that main() is called only when the script is executed directly.
if __name__ == "__main__":
    main()