Axel and others, I can appreciate the comparison to a partially applied function but not in this case. Not that it matters, but this example is more like creating an object in something like machine learning and initializing parameters without adding data. Only when you ad data and call upon some transforms and so on, does it do something.
This case is even more general. You create an object that does NOTHING. It simply holds a start/end/step set of up to three values. Lots of other functions will take this object as an argument. It can be used and reused any number of times. Strictly speaking, code like name[5:10:1] just creates a transient slice object and then uses that to get the answer. It is not delayed or partial as much as making one does nothing. Stefan mentioned functools.partial and that does create a bit of a curried function that wraps the data and holds on to it so invoking it sort of wakes the function up, with some or all data already accessible. A slice does not do that and needs some other functionality to use IT alongside whatever object you want to see a slice of. No special behavior was intended by me. I was illustrating how some methods of providing a selected view of an object are equally sensitive to the underlying data changing. A partially applied function that still takes an argument later, would have a similar problem if underlying data outside the what is stored within the function, changed, or if the saved was a reference to something that changed. But this is really far from unique. In the example given of creating a partial call, what if you made a second copy to that call then the first variable to the partial function was re-defined. -----Original Message----- From: Python-list <python-list-bounces+avi.e.gross=gmail....@python.org> On Behalf Of Axel Reichert Sent: Friday, January 13, 2023 3:22 AM To: python-list@python.org Subject: Re: To clarify how Python handles two equal objects <avi.e.gr...@gmail.com> writes: > As an example, you can create a named slice such as: > > middle_by_two = slice(5, 10, 2) > > The above is not in any sense pointing at anything yet. >From a functional programming point of view this just looks like a partially applied function, and with this in mind the behaviour to me seems to be completely as expected. No surprises here, or do I miss something? Best regards Axel -- https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
