[Python-ideas] Re: Allow with block (context manager) to return a value (e.g. to use as a builder)

Or if the context object needs different behavior, stick the "return value" in an attribute like restaurant_choices.data. On Sun, Oct 13, 2019, 2:56 PM David Mertz wrote:

Why not just:

with build_choices('Restaurant') as restaurant_choices : ...

print(restaurant_choices)

On Sun, Oct 13, 2019, 2:49 PM Steve Jorgensen wrote:

...

Here's a more fleshed-out example of the kind of usage I have in mind. Note that this does not require `with` to have any affect on variable scope. The object returned from the context manager's __enter__ method is all the context that is needed or wanted for this pattern.

restaurant_choices = with build_choices('Restaurant') as cb: # Get of nonexistent attr auto-generates matching entry. cb.BURGER_KING cb.FIVE_GUYS # Returned value is a ChoiceItem that implements __mod__ to return a # new ChoiceItem instance w/ substituted label. cb.MCDONALDS %= "McDonald's"

print(restaurant_choices) # RestaurantChoices( # ( # ('BURGER_KING', 'Burger King'), # ('FIVE_GUYS', 'Five Guys'), # ('MCDONALDS', "McDonald's")))

print(RestaurantChoices.BURGER_KING) # Prints 'BURGER_KING'

print(RestaurantChoices.value_labels['FIVE_GUYS']) # Prints 'Five Guys' _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/ZPZ47K... Code of Conduct: http://python.org/psf/codeofconduct/