Change docs for transaction.on_commit to suggest functools.partial instead of lambda

[Alex Morega]

I've recently got bitten by a silly bug:

for n in range(10):
    transaction.on_commit(lambda: do_something(n))

Of course, instead of calling do_something(0), do_something(1) ..., it's going to call do_something(9) 10 times.

The docs could help by suggesting ​functools.partial instead of lambda. The above example becomes:

for n in range(10):
    transaction.on_commit(partial(do_something, n))

If this change is a good idea I can have a go at making a PR.

[Carlton Gibson]

Hey Alex. OK... I might be a bit marginal but, certainly happy to look at a PR if you're keen to make it.

[Alex Morega]

​PR

[GitHub <noreply@…>]

In 7e6b537f:

Fixed #33939 -- Used functools.partial() in transaction.on_commit() examples.

[Carlton Gibson <carlton.gibson@…>]

In 8a8a0038:

[4.1.x] Fixed #33939 -- Used functools.partial() in transaction.on_commit() examples.

Backport of 7e6b537f5b92be152779fc492bb908d27fe7c52a from main

[Mariusz Felisiak <felisiak.mariusz@…>]

In 444b6da7:

Refs #33939 -- Improved transaction.on_commit() docs.