Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #90726
| From | Marko Rauhamaa <marko@pacujo.net> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Building CPython |
| Date | 2015-05-16 11:08 +0300 |
| Organization | A noiseless patient Spider |
| Message-ID | <87egmhrll2.fsf@elektro.pacujo.net> (permalink) |
| References | (6 earlier) <crlglfFgf05U1@mid.individual.net> <87bnhmgqrx.fsf@elektro.pacujo.net> <DWt5x.439666$qW.359562@fx20.am4> <87twvdsbom.fsf@elektro.pacujo.net> <bpw5x.561870$Zf4.150532@fx22.am4> |
BartC <bc@freeuk.com>:
> I suppose in many cases an object will have no attributes of its own,
> and so it can rapidly bypass the first lookup.
Almost all objects have quite many instance attributes. That's what
tells objects apart.
> I don't understand the need for an object creation (to represent A.B
> so that it can call it?) but perhaps such an object can already exist,
> prepared ready for use.
Note that almost identical semantics could be achieved without a class.
Thus, these two constructs are almost identical:
class C:
def __init__(self, x):
self.x = x
def square(self):
return self.x * self.x
def cube(self):
return self.x * self.square()
##
class O: pass
def C(x):
o = O()
def square():
return x * x
def cube():
return x * square()
o.square = square
o.cube = cube
return o
IOW, the class is a virtually superfluous concept in Python. Python has
gotten it probably without much thought (other languages at the time had
it). I comes with advantages and disadvantages:
+ improves readability
+ makes objects slightly smaller
+ makes object instantiation slightly faster
- goes against the grain of ducktyping
- makes method calls slower
- makes method call semantics a bit tricky
Marko
Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Building CPython BartC <bc@freeuk.com> - 2015-05-13 20:36 +0100
Re: Building CPython Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-05-13 20:58 +0100
Re: Building CPython Terry Reedy <tjreedy@udel.edu> - 2015-05-13 18:34 -0400
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-14 16:51 +0100
Re: Building CPython Chris Angelico <rosuav@gmail.com> - 2015-05-15 02:09 +1000
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-14 18:02 +0100
Re: Building CPython Dave Angel <davea@davea.name> - 2015-05-14 13:10 -0400
Re: Building CPython Chris Angelico <rosuav@gmail.com> - 2015-05-15 03:11 +1000
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-14 18:32 +0100
Re: Building CPython Chris Angelico <rosuav@gmail.com> - 2015-05-15 03:45 +1000
Re: Building CPython Terry Reedy <tjreedy@udel.edu> - 2015-05-14 14:50 -0400
Re: Building CPython Christian Gollwitzer <auriocus@gmx.de> - 2015-05-15 12:51 +0200
Re: Building CPython Terry Reedy <tjreedy@udel.edu> - 2015-05-15 17:19 -0400
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-14 19:29 +0300
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-14 22:55 +0100
Re: Building CPython MRAB <python@mrabarnett.plus.com> - 2015-05-14 23:19 +0100
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-15 01:50 +0100
Re: Building CPython Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-05-15 18:05 +1200
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-15 11:59 +0300
Re: Building CPython wxjmfauth@gmail.com - 2015-05-15 02:07 -0700
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-15 12:20 +0300
Re: Building CPython wxjmfauth@gmail.com - 2015-05-15 02:51 -0700
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-15 13:52 +0300
Re: Building CPython Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-15 22:10 +1000
Re: Building CPython Chris Angelico <rosuav@gmail.com> - 2015-05-15 22:34 +1000
Re: Building CPython wxjmfauth@gmail.com - 2015-05-15 07:11 -0700
Re: Building CPython Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-05-15 13:41 +0100
Re: Building CPython Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-05-15 13:38 +0100
Re: Building CPython Chris Angelico <rosuav@gmail.com> - 2015-05-15 19:43 +1000
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-15 13:50 +0300
Re: Building CPython Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-15 22:43 +1000
Re: Building CPython Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-15 09:00 -0600
Re: Building CPython Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-15 09:04 -0600
Re: Building CPython Chris Angelico <rosuav@gmail.com> - 2015-05-16 01:06 +1000
Re: Building CPython Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-15 20:14 +1000
Re: Building CPython Chris Angelico <rosuav@gmail.com> - 2015-05-15 20:25 +1000
Re: Building CPython Terry Reedy <tjreedy@udel.edu> - 2015-05-15 17:05 -0400
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-15 22:54 +0100
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-16 01:44 +0300
Re: Building CPython Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-05-16 00:27 +0100
Re: Building CPython Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-16 11:55 +1000
Re: Building CPython Chris Angelico <rosuav@gmail.com> - 2015-05-16 12:15 +1000
Re: Building CPython Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-05-16 03:17 +0100
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-16 01:43 +0100
Re: Building CPython MRAB <python@mrabarnett.plus.com> - 2015-05-16 02:16 +0100
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-16 11:08 +0300
Re: Building CPython Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-16 19:40 +1000
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-16 16:59 +0300
Re: Building CPython Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-17 04:18 +1000
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-16 21:55 +0300
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-17 01:51 +0300
Re: Building CPython Marko Rauhamaa <marko@pacujo.net> - 2015-05-17 23:49 +0300
Re: Building CPython Terry Reedy <tjreedy@udel.edu> - 2015-05-15 19:54 -0400
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-15 10:32 +0100
Re: Building CPython Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-05-16 12:55 +1200
Re: Building CPython Jonas Wielicki <jonas@wielicki.name> - 2015-05-17 14:25 +0200
Re: Building CPython BartC <bc@freeuk.com> - 2015-05-17 14:41 +0100
csiph-web