How do nested context managers work in Python?

How do nested context managers work in Python?

Nested context managers allow you to manage multiple resources using the with statement. You can nest them to ensure that each resource is properly managed.

Can you give me an example of using nested context managers?

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 fails to open?

If one of the files fails to open, Python will raise an exception, and the context manager will ensure that any already opened files are closed properly.

Are there any performance considerations with nested context managers?

Generally, the performance impact is minimal, but it's good practice to keep the number of nested context managers reasonable to maintain code readability.