Environment variables are dynamic values set outside your Python code that provide configuration details to your applications. In DevOps workflows, environment variables play a crucial role by allowing you to manage settings and secrets—such as database credentials, API keys, or deployment targets—without embedding them directly in your scripts. This separation of code and configuration helps you adapt applications to different environments, such as development, testing, and production, simply by changing environment variable values. Using environment variables also makes scripts more portable and maintainable, since you can reuse the same codebase across various systems without modification.

import os

# Get the value of the 'HOME' environment variable
home_directory = os.environ.get("HOME")
print("Your home directory is:", home_directory)

# List all environment variables
for key, value in os.environ.items():
    print(f"{key}: {value}")

Managing sensitive data such as passwords, tokens, or secret keys is a core concern in DevOps. Storing these values in environment variables keeps them out of your source code, reducing the risk of accidental exposure in version control or code reviews. However, you must still be careful: environment variables can sometimes be viewed by other processes on the same system, so always follow best practices for securing your environment and limit access to only what is necessary. Tools like encrypted secrets management and restricted user permissions further help protect sensitive data.

import os

# Try to get the value of 'API_KEY', or use a default if not set
api_key = os.environ.get("API_KEY", "default_api_key")
print("API key in use:", api_key)