How to Get Currency Exchange Rates with Fixer.io API in Python

Introduction to Fixer.io API

• Fixer.io is a simple and lightweight API for current and historical foreign exchange rates published by the European Central Bank. With Fixer, you can retrieve exchange rate data in real-time and historical formats.
• It offers a Free Plan with limited features, but you can access more endpoints and data sets with the paid subscriptions.

Setting Up Your Environment

• Ensure you have Python installed and an environment setup for your project. A virtual environment is recommended to manage dependencies effectively.
• Install the necessary libraries using pip. You will need the requests library to make HTTP requests to the API. Run the following command in your terminal or command prompt:

pip install requests

Making a Request to Fixer.io API

• To interact with the API, you'll construct a URL for a GET request. The endpoint for the latest rates is http://data.fixer.io/api/latest.
• You need to include your access key in the request for authentication. This is done by adding a parameter named access\_key to your URL.

import requests

API_KEY = 'YOUR_ACCESS_KEY'
BASE_URL = 'http://data.fixer.io/api/'

def get_latest_rates():
    url = BASE_URL + 'latest'
    params = {
        'access_key': API_KEY
    }
    response = requests.get(url, params=params)
    if response.status_code == 200:
        data = response.json()
        print(data)
    else:
        print(f"Failed to retrieve data: {response.status_code}")

get_latest_rates()

Parsing the API Response

• The API response will be in JSON format. It typically includes a dictionary with keys like 'success', 'timestamp', 'base', 'date', and 'rates'.
• Rates will be another dictionary inside the JSON, containing currency codes as keys and their exchange rates as values.

def parse_exchange_rates(data):
    if not data.get('success'):
        print("Failed to retrieve rates:", data.get('error'))
        return
    base_currency = data['base']
    rates = data['rates']
    for currency, rate in rates.items():
        print(f"1 {base_currency} = {rate} {currency}")

response_data = get_latest_rates()

if response_data:
    parse_exchange_rates(response_data)

Fetching Historical Exchange Rates

• To retrieve historical rates, adjust the endpoint in your request to http://data.fixer.io/api/{date}, where {date} is in the format YYYY-MM-DD.
• Add the desired date to the URL and make the request similar to how you fetched the latest rates.

def get_historical_rates(date):
    url = BASE_URL + date
    params = {
        'access_key': API_KEY
    }
    response = requests.get(url, params=params)
    if response.status_code == 200:
        return response.json()
    else:
        print(f"Failed to retrieve data: {response.status_code}")
        return None

historical_data = get_historical_rates('2023-05-01')

if historical_data:
    parse_exchange_rates(historical_data)

Handling Common Issues

• Always check for the success key in the response to verify that your request executed correctly.
• Handling exceptions and errors gracefully will ensure your application is robust. Consider implementing retry logic or alternate services in case of API downtime.
• Manage API request limits to stay within your subscription's quota, potentially by batching requests or caching responses.