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Pythonic Approach to Environment Variables

Guide on Accessing and Setting Environment Variables in Python

Modifying Environment Variables in Python Scripts
Modifying Environment Variables in Python Scripts

Pythonic Approach to Environment Variables

In the realm of Python programming, environment variables play a crucial role in storing sensitive information and configuring a program's behaviour. This article aims to provide a tutorial on working with environment variables in Python, explaining how to set, get, and manage them effectively.

Understanding Environment Variables in Python

Environment variables in Python are implemented through the module. The provides a mapping of key-value pairs that represent the process environment. To get all environment variables, simply run .

An example use case for environment variables is storing a secret key for an API. Using environment variables improves sensitive data security and helps keep secret keys private when sharing source code on platforms like GitHub.

Setting Environment Variables in Python

To set an environment variable in Python, you can assign a value to the key in . For instance:

```python import os

os.environ["VARIABLE_NAME"] = "VALUE" ```

However, it's important to note that the changes to environment variables in Python are only valid for the current session while running the code. To set and get environment variables persistently beyond the current session, you need to define the variables at the operating system level or store them in a file.

Setting Environment Variables Persistently

At the OS level:

On Windows PowerShell, use:

```powershell

```

To set for all users (requires admin rights), use instead of .

On Linux/macOS, you typically add export statements to shell config files like or :

This will set the variable persistently for future sessions.

Using files:

Store key-value pairs in a file and load them in Python using libraries like . This way, environment variables are managed outside the terminal session but can be loaded dynamically by Python.

Accessing Environment Variables in Python

Use the module to get environment variables as strings:

```python import os

value = os.environ.get('VARIABLE_NAME', 'default_value') ```

You may need to convert the string to other types manually.

Key Points to Remember

  • Setting environment variables via in Python only affects the current Python process and its child processes; it does not persist beyond that session.
  • To make environment variables persist beyond current sessions, set them externally via OS commands or files.
  • Some tools or platforms may offer GUI or CLI commands to manage environment variables persistently (e.g., Google Cloud Composer, Langflow CLI).

This approach aligns with common practices described in multiple sources: Python code reads environment variables set outside its session, environment variables set inside a Python process are temporary, and persistent setting requires OS-level configuration or files loaded at runtime[1][2].

This article focuses on working with environment variables in Python, including getting existing variables and setting variables for a session. Environment variables are variables stored outside a program at the operating system level, aiding in automation by helping avoid manual updates in the code base.

The article was originally published on December 20, 2022, at pyshark.com.

[1] https://docs.python.org/3/library/os.html#os.environ [2] https://realpython.com/python-environment-variables/

  1. Using technologylike the module in Python allows developers to set, get, and manage environment variables, which are crucial for storing sensitive information and configuring a program's behavior.
  2. To ensure environment variables persist beyond the current Python session, they should be set at the operating system level or stored in a file, emphasizing the importance of technology in securing sensitive data like API keys when sharing source code on platforms like GitHub.

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