def get_env_var()

in main.py [0:0]

• 5 lines of code
• 2 McCabe index (conditional complexity)

def get_env_var(var_name: str) -> str:
    """Retrieve required environment variable or raise error."""
    value = os.getenv(var_name)
    if not value:
        raise EnvironmentError(f"{var_name} is not set.")
    return value