How can I use nested context managers in Python?

How can I use nested context managers in Python?

You can use the contextlib module to manage multiple context managers in a nested manner. For example, you can use the with statement to open multiple files at once.

Can you show me a code example?

Sure! Here's a simple example:

from contextlib import ExitStack

with ExitStack() as stack:
    file1 = stack.enter_context(open('file1.txt', 'r'))
    file2 = stack.enter_context(open('file2.txt', 'r'))
    # Now you can read from both files
    data1 = file1.read()
    data2 = file2.read()

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

If one of the files doesn't exist, a FileNotFoundError will be raised. The ExitStack will ensure that any opened files are properly closed, even if an error occurs.

Is there a way to handle exceptions when using nested context managers?

Yes, you can wrap the with statement in a try-except block to handle exceptions gracefully. This way, you can manage errors while still ensuring resources are cleaned up.