What are nested context managers in Python?

What are nested context managers in Python?

Nested context managers allow you to manage multiple resources using the with statement in Python. They help ensure that resources are properly acquired and released.

Can you give me an example of how to use them?

Sure! Here's a simple example:

with open('file1.txt') as f1, open('file2.txt') as f2:
    data1 = f1.read()
    data2 = f2.read()

This opens both files and ensures they are closed properly after the block.

What happens if one of the files doesn't exist?

If one of the files doesn't exist, a FileNotFoundError will be raised, and the context manager will ensure that any resources opened before the error are still properly closed.

Are there any best practices for using nested context managers?

Yes! It's best to keep the nesting shallow for readability, and ensure that the resources are related. Also, handle exceptions appropriately to avoid resource leaks.