[Python-Dev] PEP 557: Data Classes (original) (raw)

Gustavo Carneiro gjcarneiro at gmail.com
Thu Oct 12 09:16:21 EDT 2017

On 12 October 2017 at 11:20, Steve Holden <steve at holdenweb.com> wrote:

On Thu, Oct 12, 2017 at 9:20 AM, Mike Miller <python-dev at mgmiller.net> wrote:

On 2017-10-12 00:36, Stéfane Fermigier wrote: "An object that is not defined by its attributes, but rather by a thread of continuity and its identity." (from https://en.wikipedia.org/wiki/ Domain-drivendesign#Buildingblocks)

Not sure I follow all this, but Python objects do have identities once instantiated. e.g. >>> id('') ​It seems to me that the quoted document is attempting to make a distinction ​similar to the one between classes (entities) and instances (value objects). The reason I liked "row" as a name is because it resembles "vector" and hence is loosely assocaited with the concept of a tuple as well as being familiar to database users. In fact the answer to a relational query was, I believe, originally formally defined as a set of tuples.

But rows and tuples are usually immutable, at least in database terms. These data classes are not immutable (by default). If you want tuple-like behaviour, you can continue to use tuples.

I see dataclasses as something closer to C struct. Most likely someone already considered struct as name; if not, please consider it. Else stick with dataclass, it's a good name IMHO. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20171012/cefcd9a7/attachment.html>

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