How can I access environment variables in Python, JavaScript, and Ruby?

How can I access environment variables in Python, JavaScript, and Ruby?

In Python, you can use the os module: import os; value = os.getenv('VARIABLE_NAME'). In JavaScript, use process.env.VARIABLE_NAME in Node.js. For Ruby, you can access it with ENV['VARIABLE_NAME'].

Are there any differences in how these languages handle missing variables?

Yes, in Python, os.getenv returns None if the variable is missing. In JavaScript, process.env.VARIABLE_NAME returns undefined, and in Ruby, ENV['VARIABLE_NAME'] returns nil.

Can I set environment variables in these languages?

Yes, you can set them in your terminal or command line before running your script. For example, in Unix-like systems, you can use export VARIABLE_NAME=value.

What about accessing environment variables in a web application?

In web applications, you typically access environment variables on the server-side, and you can pass them to the client-side as needed, ensuring sensitive data is not exposed.