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Groups > comp.lang.python > #91502
| Newsgroups | comp.lang.python |
|---|---|
| Date | 2015-05-29 14:06 -0700 |
| References | <c03de3a7-3429-44a3-8241-5a7d81b9aefc@googlegroups.com> <33b7ab62-8cc2-4a27-b229-64c94bce16b6@googlegroups.com> <mailman.202.1432919880.5151.python-list@python.org> |
| Message-ID | <656488c4-e706-4fea-ab45-3d1454e35a7f@googlegroups.com> (permalink) |
| Subject | Re: What is considered an "advanced" topic in Python? |
| From | sohcahtoa82@gmail.com |
On Friday, May 29, 2015 at 10:18:29 AM UTC-7, Ethan Furman wrote: > On 05/29/2015 10:03 AM, sohcahtoa82@gmail.com wrote: > > On Friday, May 29, 2015 at 9:02:06 AM UTC-7, Mike Driscoll wrote: > > >> I've been asked on several occasions to write about intermediate or advanced topics > >> in Python and I was wondering what the community considers to be "intermediate" or > >> "advanced". I realize we're all growing in our abilities with the language, so this > >> is going to be very subjective, but I am still curious what my fellow Python > >> developers think about this topic. > > > > Metaclasses. > > > > I've read about them. I still don't understand them, why you would want them, and what you gain from them. > > Metaclasses change the way a class behaves. > > For example, the new (in 3.4) Enum class uses a metaclass. > > class SomeEnum(Enum): > first = 1 > second = 2 > third = 3 > > The metaclass changes normal class behavior to: > > - support iterating: list(SomeEnum) --> [SomeEnum.first, SomeEnum.second, SomeEnum.third] > - support a length: len(SomeEnum) --> 3 > - not allow new instances to be created: --> SomeEnum(1) is SomeEnum(1) # True > > -- > ~Ethan~ Regarding the first two, you can implement __iter__ and __len__ functions to create that functionality, though those functions would operate on an instance of the class, not the class itself. As for the third, can't you override the __new__ function to make attempts to create a new instance just return a previously created instance?
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What is considered an "advanced" topic in Python? Mike Driscoll <kyosohma@gmail.com> - 2015-05-29 09:01 -0700
Re: What is considered an "advanced" topic in Python? Joel Goldstick <joel.goldstick@gmail.com> - 2015-05-29 12:08 -0400
Re: What is considered an "advanced" topic in Python? Mike Driscoll <kyosohma@gmail.com> - 2015-05-29 09:55 -0700
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-05-30 02:09 +1000
Re: What is considered an "advanced" topic in Python? Mike Driscoll <kyosohma@gmail.com> - 2015-05-29 09:57 -0700
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-05-30 03:08 +1000
Re: What is considered an "advanced" topic in Python? random832@fastmail.us - 2015-05-31 23:18 -0400
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-06-01 13:43 +1000
Re: What is considered an "advanced" topic in Python? Laura Creighton <lac@openend.se> - 2015-06-01 09:58 +0200
Re: What is considered an "advanced" topic in Python? Marko Rauhamaa <marko@pacujo.net> - 2015-06-01 12:36 +0300
Zero [was Re: What is considered an "advanced" topic in Python?] Steven D'Aprano <steve@pearwood.info> - 2015-06-01 22:07 +1000
Re: Zero [was Re: What is considered an "advanced" topic in Python?] Laura Creighton <lac@openend.se> - 2015-06-01 14:52 +0200
Re: Zero [was Re: What is considered an "advanced" topic in Python?] Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-06-01 13:56 +0100
Re: Zero [was Re: What is considered an "advanced" topic in Python?] Skip Montanaro <skip.montanaro@gmail.com> - 2015-06-01 08:14 -0500
Re: Zero [was Re: What is considered an "advanced" topic in Python?] Dave Farrance <df@see.replyto.invalid> - 2015-06-01 15:39 +0100
Re: Zero [was Re: What is considered an "advanced" topic in Python?] Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-01 18:35 +0100
Re: Zero [was Re: What is considered an "advanced" topic in Python?] Terry Reedy <tjreedy@udel.edu> - 2015-06-01 17:32 -0400
Re: Zero [was Re: What is considered an "advanced" topic in Python?] Marko Rauhamaa <marko@pacujo.net> - 2015-06-01 16:18 +0300
Re: Zero [was Re: What is considered an "advanced" topic in Python?] random832@fastmail.us - 2015-06-01 09:32 -0400
Re: What is considered an "advanced" topic in Python? Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-06-01 11:44 +0100
Re: What is considered an "advanced" topic in Python? Marko Rauhamaa <marko@pacujo.net> - 2015-06-01 13:54 +0300
Re: What is considered an "advanced" topic in Python? Rustom Mody <rustompmody@gmail.com> - 2015-06-01 22:33 -0700
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-06-01 19:45 +1000
Re: What is considered an "advanced" topic in Python? Laura Creighton <lac@openend.se> - 2015-06-01 12:28 +0200
Re: What is considered an "advanced" topic in Python? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-01 14:22 +0100
Re: What is considered an "advanced" topic in Python? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-01 11:34 +0100
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-06-01 20:36 +1000
Re: What is considered an "advanced" topic in Python? Laura Creighton <lac@openend.se> - 2015-06-01 13:00 +0200
Re: What is considered an "advanced" topic in Python? Laura Creighton <lac@openend.se> - 2015-06-01 13:24 +0200
Re: What is considered an "advanced" topic in Python? Marko Rauhamaa <marko@pacujo.net> - 2015-06-01 14:57 +0300
Re: What is considered an "advanced" topic in Python? BartC <bc@freeuk.com> - 2015-06-01 13:27 +0100
Re: What is considered an "advanced" topic in Python? MRAB <python@mrabarnett.plus.com> - 2015-06-01 13:27 +0100
Re: What is considered an "advanced" topic in Python? Laura Creighton <lac@openend.se> - 2015-06-01 17:07 +0200
Re: What is considered an "advanced" topic in Python? alister <alister.nospam.ware@ntlworld.com> - 2015-06-01 15:26 +0000
Re: What is considered an "advanced" topic in Python? Laura Creighton <lac@openend.se> - 2015-06-01 17:51 +0200
Re: What is considered an "advanced" topic in Python? MRAB <python@mrabarnett.plus.com> - 2015-06-01 18:06 +0100
Re: What is considered an "advanced" topic in Python? Marko Rauhamaa <marko@pacujo.net> - 2015-06-01 20:14 +0300
Re: What is considered an "advanced" topic in Python? BartC <bc@freeuk.com> - 2015-06-01 16:42 +0100
Re: What is considered an "advanced" topic in Python? Grant Edwards <invalid@invalid.invalid> - 2015-06-01 17:02 +0000
Re: What is considered an "advanced" topic in Python? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-01 18:45 +0100
Re: What is considered an "advanced" topic in Python? Grant Edwards <invalid@invalid.invalid> - 2015-06-01 18:23 +0000
Re: What is considered an "advanced" topic in Python? BartC <bc@freeuk.com> - 2015-06-01 13:24 +0100
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-06-01 23:52 +1000
Re: What is considered an "advanced" topic in Python? BartC <bc@freeuk.com> - 2015-06-01 16:17 +0100
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-06-02 02:10 +1000
Re: What is considered an "advanced" topic in Python? Rustom Mody <rustompmody@gmail.com> - 2015-06-01 21:46 -0700
Re: What is considered an "advanced" topic in Python? Skip Montanaro <skip.montanaro@gmail.com> - 2015-05-29 11:39 -0500
Re: What is considered an "advanced" topic in Python? Mike Driscoll <kyosohma@gmail.com> - 2015-05-29 09:58 -0700
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-05-30 02:50 +1000
Re: What is considered an "advanced" topic in Python? Todd <toddrjen@gmail.com> - 2015-05-29 19:02 +0200
Re: What is considered an "advanced" topic in Python? sohcahtoa82@gmail.com - 2015-05-29 10:03 -0700
Re: What is considered an "advanced" topic in Python? Ethan Furman <ethan@stoneleaf.us> - 2015-05-29 10:17 -0700
Re: What is considered an "advanced" topic in Python? sohcahtoa82@gmail.com - 2015-05-29 14:06 -0700
Re: What is considered an "advanced" topic in Python? Jason Swails <jason.swails@gmail.com> - 2015-05-29 17:28 -0400
Re: What is considered an "advanced" topic in Python? Ethan Furman <ethan@stoneleaf.us> - 2015-05-29 14:39 -0700
Re: What is considered an "advanced" topic in Python? Ethan Furman <ethan@stoneleaf.us> - 2015-05-29 14:44 -0700
Re: What is considered an "advanced" topic in Python? Marko Rauhamaa <marko@pacujo.net> - 2015-05-29 20:24 +0300
Re: What is considered an "advanced" topic in Python? Todd <toddrjen@gmail.com> - 2015-05-29 19:03 +0200
Re: What is considered an "advanced" topic in Python? Steven D'Aprano <steve@pearwood.info> - 2015-05-30 03:55 +1000
Re: What is considered an "advanced" topic in Python? Mike Driscoll <kyosohma@gmail.com> - 2015-05-29 13:38 -0700
Re: What is considered an "advanced" topic in Python? Sturla Molden <sturla.molden@gmail.com> - 2015-05-30 12:15 +0000
Re: What is considered an "advanced" topic in Python? jonathon <jonathon.blake@gmail.com> - 2015-05-30 19:32 +0000
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-05-31 08:24 +1000
Re: What is considered an "advanced" topic in Python? "C.D. Reimer" <chris@cdreimer.com> - 2015-05-30 18:28 -0700
Re: What is considered an "advanced" topic in Python? Rustom Mody <rustompmody@gmail.com> - 2015-05-30 20:30 -0700
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-05-31 14:25 +1000
Re: What is considered an "advanced" topic in Python? Rustom Mody <rustompmody@gmail.com> - 2015-05-30 21:46 -0700
Re: What is considered an "advanced" topic in Python? Chris Angelico <rosuav@gmail.com> - 2015-05-31 14:58 +1000
Re: What is considered an "advanced" topic in Python? Rustom Mody <rustompmody@gmail.com> - 2015-05-30 22:18 -0700
Re: What is considered an "advanced" topic in Python? Gene Heskett <gheskett@wdtv.com> - 2015-06-01 09:49 -0400
Re: What is considered an "advanced" topic in Python? Denis McMahon <denismfmcmahon@gmail.com> - 2015-06-01 15:30 +0000
Re: What is considered an "advanced" topic in Python? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-06-01 20:33 -0400
Re: What is considered an "advanced" topic in Python? Gene Heskett <gheskett@wdtv.com> - 2015-06-01 23:30 -0400
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