On Thu, Jul 26, 2018 at 12:20 AM, Stephan Houben
<stephan...@gmail.com.invalid> wrote:
> Op 2018-07-24, Chris Angelico schreef <ros...@gmail.com>:
>> On Wed, Jul 25, 2018 at 9:18 AM, Rob Gaddi
>><rgaddi@highlandtechnology.invalid> wrote:
>>> On 07/24/2018 01:07 PM, Chris Angelico wrote:
>>> I suppose one valid usage would be this sort of thing:
>>>
>>> fn = {
>>> int: dispatchInt,
>>> str: dispatchStr,
>>> list: dispatchList,
>>> type(None): dispatchNone
>>> }[type(x)]
>>> fn(x)
>>>
>>
>> True, but that would be useful only in a very few situations, where
>> you guarantee that you'll never get any subclasses. So if you're
>> walking something that was decoded from JSON, and you know for certain
>> that you'll only ever get those types (add float to the list and it's
>> basically covered), then yes, you might do this; and then I would say
>> that using "type(None)" is the correct spelling of it.
>
> This is actual code I have:
>
> @singledispatch
> def as_color(color):
> """Convert object to QColor."""
> return QtGui.QColor(color)
>
> as_color.register(type(None), lambda x: QtGui.QColor(0, 0, 0, 0))
>
Yep, I would agree with that. If it's type-based dispatch, then
type(None) is the cleanest and easiest way to spell it.
ChrisA
--
https://mail.python.org/mailman/listinfo/python-list
