How Can I Access Environment Variables in Python

how-can-i-access-environment-variables-in-python

Environment variables are a convenient way to store system-level information that can be accessed by multiple applications.

They play a crucial role in providing a secure, flexible and scalable infrastructure for your applications.

In this tutorial, we’ll explore how you can access environment variables in Python.

We’ll start with a brief overview of what environment variables are, why you should use them and the different ways you can access them in Python.

What are Environment Variables?

Environment variables are a set of key-value pairs that are stored in the operating system and can be accessed by applications running on that system.

They provide a convenient way to store and share information between different parts of an application or between multiple applications.

Why Use Environment Variables?

Using environment variables instead of hard-coded values has several advantages. They allow you to:

  1. Store sensitive information such as passwords, API keys, and other secrets that should not be hard-coded in your source code.
  2. Configure your application differently in different environments such as development, testing and production.
  3. Make it easier to manage and update configuration information without having to modify and recompile the source code.

How to Access Environment Variables in Python

There are several ways to access environment variables in Python. Let’s explore the most commonly used methods:

1. os.environ

The os module provides a dictionary-like object called os.environ that can be used to access environment variables in Python.

Here’s an example of how you can access the value of an environment variable using os.environ:

import os

print(os.environ['MY_VAR'])

In this example, we’re accessing the value of the MY_VAR environment variable. If the variable does not exist, a KeyError will be raised.

To avoid this, you can use the get method of os.environ, which returns None if the variable is not found:

import os

my_var = os.environ.get('MY_VAR')

if my_var:
    print(my_var)
else:
    print('MY_VAR is not set')

2. python-dotenv

The python-dotenv library provides a simple way to load environment variables from a file into the os.environ dictionary.

This can be useful when you want to store environment variables in a separate file, instead of setting them directly in the operating system.

Here’s an example of how you can use python-dotenv to load environment variables:

import os
from dotenv import load_dotenv

load_dotenv()

print(os.getenv('MY_VAR'))

In this example, we’re using the load_dotenv function to load environment variables from a file named .env.

The .env file should be stored in the same directory as your Python script and should contain the environment variables in the following format:

MY_VAR=value

Conclusion

In this post, we explored how to access environment variables in Python using the os.environ dictionary and the python-dotenv library.

We saw that using environment variables is a convenient and secure way to store system-level information that can be accessed by multiple applications.

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