Is it ok to call sys.exit() from within context manager in Python?

For example, I’ve something using the "with" statement, and I do something inside the "with" that can throw an exception, and I want to catch the exception so that I can use sys.exit(0) / sys.exit(1) so the pass / fail result can be picked up by the calling script/shell.

with open("test.txt", "r") as f:
    try:
        do_something_with(f)
    except Exception as e:
        sys.exit(1)
    else:
        sys.exit(0)

In my case, it’s not a file I’m opening but a connection to a server, and I just want to know if the context manager’s __exit__ will get called properly, or if sys.exit() somehow bypasses it?

>Solution :

Yes, the context manager’s __exit__ will still be called.

You can test this yourself by creating your own dummy context manager:

import contextlib
import sys


@contextlib.contextmanager
def my_context_manager():
    try:
        print("enter")
        yield
    finally:
        print("exit")


with my_context_manager():
    print("inside")
    sys.exit(1)

Running this script outputs

enter
inside
exit

This should make sense, since sys.exit works by raising SystemExit, which is just a slightly special exception that does not inherit from Exception. You can even catch it if you like:

try:
    sys.exit(1)
except SystemExit:
    print("caught exit")

print("I survived sys.exit!")

outputs

caught exit
I survived sys.exit!