How does the python context manager work
Maybe it's not a 'the context' manager, but 'a' context manager. Either way, for quite a long time i've wanted to make my own. Only today did I get a chance to apply it. The docs are not massive because it isn't a big topic. I have no idea how it works, but as long as it does work we shouldn't need to care how it works under the hood.Why use a context manager at all?
If used properly it allows you to hide setup and breakdown. But even if you use it in passing as a way to limit the availability of a set of parameters to a narrow scope, it's probably neat -- i don't know i've not had a battle with it yet.anyway, I think it's cool.
from contextlib import contextmanager @contextmanager def surfsup(): info = lambda: None info.breaker = ['teleprompt'] info.charly = ['humate', 0, 2, 3] yield info with surfsup() as i: print(i.breaker) print(i.charly)the parens are optional in the yield and
as (args, printer)
from contextlib import contextmanager def printer(fstr): print(fstr * 2) @contextmanager def conjunct(): kn = lambda: None kn.do = 'Yes' kn.dont = 'No' yield (kn, printer) with conjunct() as (args, printer): printer(args.do) printer(args.dont)