Securely Managing API Keys with Environment Variables in Python

import os
import requests

def get_api_key(key_name):
    """
    Retrieves an API key from environment variables.
    Raises an error if the key is not found.
    """
    api_key = os.environ.get(key_name)
    if not api_key:
        raise ValueError(f"Environment variable '{key_name}' not set.")
    return api_key

def make_authenticated_api_call(endpoint_url):
    """
    Example function demonstrating an API call using a securely retrieved key.
    """
    try:
        my_api_key = get_api_key("MY_SERVICE_API_KEY")

        headers = {
            "X-API-Key": my_api_key,
            "Accept": "application/json"
        }

        response = requests.get(endpoint_url, headers=headers)
        response.raise_for_status()
        return response.json()

    except ValueError as e:
        print(f"Configuration error: {e}")
        return None
    except requests.exceptions.RequestException as e:
        print(f"API request failed: {e}")
        return None

if __name__ == "__main__":
    try:
        key = get_api_key("MY_SERVICE_API_KEY")
        print(f"Successfully retrieved API Key (first 5 chars): {key[:5]}...")
    except ValueError as e:
        print(f"Error: {e}")
    
    print("
To test, set environment variable:
export MY_SERVICE_API_KEY=\"your_key_here\"
")