Simple Currency Converter - How to Build a Simple Currency Converter in Python
- Anubhav Somani
- 4 days ago
- 2 min read
Simple Currency Converter. This project is a fantastic real-world example that teaches you how to use dictionaries to manage data and perform calculations based on user input.
First, here is the explanation of how the project is built.
How the "Simple Currency Converter" is Made
The Core Idea: The goal is to create a command-line tool that can convert a specific amount of money from one currency to another using a predefined set of exchange rates.
The Data Structure: A Dictionary for Rates: A dictionary is the perfect way to store our exchange rates. We'll create a dictionary where the keys are the three-letter currency codes (e.g., 'USD', 'INR', 'EUR') and the values are their exchange rates relative to a common base currency. For simplicity, we'll use the US Dollar (USD) as our base. This means the rate for 'USD' will be 1.0.
Getting User Input: We need to collect three pieces of information from the user:
The amount of money to convert.
The currency code they are converting from (e.g., 'USD').
The currency code they want to convert to (e.g., 'INR'). We'll use the input() function for each of these and convert the currency codes to uppercase using .upper() to match the keys in our dictionary.
Safe Input Handling:
We'll wrap the code for getting the amount in a try-except block to ensure the user enters a valid number. If they type text, the program will show an error and exit gracefully.
We also need to check if the currency codes the user entered actually exist in our rates dictionary. We do this with a simple if statement to prevent the program from crashing if they enter an unsupported currency.
The Conversion Logic: Converting between any two currencies is a simple two-step math problem when you have a base currency:
Step 1: Convert to the Base Currency. First, we take the user's amount and convert it into our base currency (USD). The formula is: amount / rate_of_the_source_currency.
Step 2: Convert from the Base to the Target. Now that we have the value in USD, we can convert it to the target currency. The formula is: amount_in_usd * rate_of_the_target_currency.
Displaying the Result: Once the calculation is complete, we use a formatted f-string to display the result to the user in a clear and readable way, showing the original amount, the source currency, the final amount, and the target currency.
Lucky Link - https://amzn.to/47WluHA
Comments