Re: [Tutor] Name for this type of class?
Thanks for everyone's feedback. Some interesting thoughts including Alan's "classes should never be named for their data but for their function" feedback. I'm going to have to noodle on that one. Good stuff! Malcolm ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Name for this type of class?
On 8/3/19 10:56 AM, Malcolm Greene wrote: > Thanks for everyone's feedback. Some interesting thoughts including Alan's > "classes should never be named for their data but for their function" > feedback. I'm going to have to noodle on that one. Good stuff! And more: if the class is really just a data container, then no need to make it a class. Use a namedtuple (or as Cameron suggested, types.SimpleNamespace). Of course we still don't know if that's the case... General comment on naming: you don't need to qualify things if the context makes it clear, all it does is make you type more stuff (or, I guess, exercise autocomplete in your IDE). A favorite one is to call your custom exception MyProgramSpecificException. Since this is going to appear in a line with raise or except in it, the word Exception is superfluous. This comes up in regards to an idea of using something like TelemetryData or TelemetryStatistics. It also comes up here: >> file_count >> line_count >> byte_count >> row_count >> batch_count >> job_count >> error_count >> warning_count why not "files", "lines", "bytes"... the plural form already tells you it's a counter. Opinions, we all have 'em :) ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Name for this type of class?
On 2019-08-03 10:16, Mats Wichmann wrote: . It also comes up here: file_count line_count byte_count row_count batch_count job_count error_count warning_count why not "files", "lines", "bytes"... the plural form already tells you it's a counter. To me "files", "lines", "bytes" implies collections of files, lines bytes. (i.e. arrays or tuples...) "___count" implies an integer. If the latter, I'd use "n_files", "n_lines" ... (possibly without the underscores if you find typing them a bother.) Comments? ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Name for this type of class?
On 8/3/19 1:40 PM, Alex Kleider wrote: > On 2019-08-03 10:16, Mats Wichmann wrote: > >> . It also comes up here: >> file_count line_count byte_count row_count batch_count job_count error_count warning_count >> >> why not "files", "lines", "bytes"... the plural form already tells you >> it's a counter. > > To me "files", "lines", "bytes" implies collections of files, lines > bytes. (i.e. arrays or tuples...) > "___count" implies an integer. > If the latter, I'd use "n_files", "n_lines" ... (possibly without the > underscores if you find typing them a bother.) > Comments? I agree, plural nouns imply collections, and collections should generally be plural nouns. file_count is fine to me, or it could be numfiles or nfiles (possibly adding the underscore) -- Richard Damon ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Name for this type of class?
On 03/08/2019 17:56, Malcolm Greene wrote: >... interesting thoughts including Alan's "classes should never be named > for their data but for their function" feedback. I'm going to have to > noodle on that one. Let me expand slightly. Go back to the fundamentals of OOP. OOP is about programs composed of objects that communicate by sending each other messages. Those messages result in the objects executing a method. Objects, therefore are defined by the set of messages that can be sent to them. By their behaviour in other words. The data they contain should only be there to support the behaviour. So an object should expose a set of methods that determine what it can do. It therefore stands to reason that the class (the template for the objects) should have a name that reflects the nature of the messages that can be sent. What kind of thing offers those kinds of capabilities? Once you can describe the operations that the object can perform you can usually find a name that describes the kind of object. One of the anti-patterns of OOP is having classes that expose methods that are unrelated to each other. Then we just have a bunch of data and some functions collected together but no coherent concept. It could be two(or more) genuine classes accidentally merged into one. Or it could be a plain module masquerading as a class. Another clue is where you only ever need a single instance of this "class". That's often a sign that it should just be a module. (There are a very few genuine singleton use cases though, so it's not a cast iron rule.) HTH. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Name for this type of class?
NB am heading somewhat OT NBB Python3+ On 3/08/19 12:38 PM, Alan Gauld via Tutor wrote: On 03/08/2019 00:47, Malcolm Greene wrote: Anyways, I'm looking for help coming up for the proper name for a class that collects the following type of telemetry data Classes should never be named for their data but for their function. What does this class do? What operations does it support. This statement caused me to double-take. Do I misunderstand? Quick survey of my PC's Projects directory:- sure-enough, few of my classNMs are verbs and convey little/no idea of function. (to a degree one's expectations/experience lead to ideas of (what might be) included in its functionality) They are almost exclusively nouns, eg Customer, Person, Organisation; rather than verbs/functions, eg Selling, Addressing, Billing. [I'm not an OOP-native, and embraced OOP concepts as extensions to practices learned whilst programming with languages such as COBOL!] Part of my introduction to OOP included the word "entity". A class was to represent an entity. An entity would be described (have attributes), just like a data-record; and it would have associated actions (methods or procedures) which acted on the entity's attributes. An entity was described as a 'thing' - no mention of an entity being an action, even though 'things' do 'stuff'. Python is not particularly dogmatic or "pure" in its following of the OOP paradigm. Unlike some languages it does not insist on OOP and will support elements of both "procedural" and "functional" programming. For this discussion then, a Wikipedia definition* 'will do'. What is included in OOP? [sometimes have 'translated' into Python terminology] - objects - data attributes - methods - inheritance - instances and dynamic dispatch - encapsulation [dotted notation] - composition [will come back to this...] - inheritance/delegation [ditto] - polymorphism [sub-classing] NB the article was no help with regard to the naming of objects/classes. Simple comprehensions of inheritance and composition boil down to the phrases "is a" and "has a". The subjects and objects of such sentences will surely be a noun, rather than a verb? Employee is a Person Circle/Oval/Square/Triangle/Shape has a CentralPoint Thus: class Person(): ... class Employee( Person ): ... Python says "everything is an object" and makes little/no distinction between "type" and "class": >>> class C: pass ... >>> i = C() >>> type( i ) >>> i.__class__ >>> type( C ) >>> C.__class__ So, what are Python's base types/objects/classes? eg int, str, list. Are these "data or function"? Expand that outwards into the PSL. Same: numbers, decimals, fractions. However, does "math" convey more "function" than "data"? There's current discussion about concerns of the age/relevance/maintenance of certain members within the PSL. So, let's look at a recent addition (it even features O-O in its description): "pathlib — Object-oriented filesystem paths". Function or data? Let's argue that it is a library not a class/object per-se. Fine. However, the six (major) classes that library contains, eg Path, PosixPath, are all nouns! At first I thought Inspect might be different, but (it is billed as a module of functions cf classes!) the classNMs are nouns (one is even called "Attribute"). The functions though, are indeed verbs, eg getargs(). Whither "Classes should never be named for their data but for their function."? WebRef: https://en.wikipedia.org/wiki/Object-oriented_programming -- Regards =dn ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
