Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder2.enfer-du-nord.net!tudelft.nl!txtfeed1.tudelft.nl!multikabel.net!newsfeed10.multikabel.net!xlned.com!feeder7.xlned.com!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=O/dNgRcGVLDCAvIdSPrzWsSZy2qyZUKvPZexDBDGoHjK93MZIiysjSNmNRda4cFaWhohGPdlpmhIQgJXOJzmOkNIzV7UJoNWCRCQ2216uNCFTGQwbYx/nRJhbpsA5DdONIJu+mexQ1WxZI4aDt7HLPh/teB0JdoY/xArotVlU8A=;
References: <CABgq=FyhR+Ldujj3YKRBpVXRVoeoayuXZviUUcNx-gXnFiHLSw@mail.gmail.com> <CACoeR0xV=28j6rFHm1ep3gzH9C0sbDqyxRRwX-JrVm3G+rrXww@mail.gmail.com> <1333174946.18436.YahooMailNeo@web121506.mail.ne1.yahoo.com> <jl6ma0$ptg$1@dough.gmane.org> <mailman.1200.1333352587.3037.python-list@python.org> <4f7962b0$0$29981$c3e8da3$5496439d@news.astraweb.com> <1333357906.6147.YahooMailNeo@web121503.mail.ne1.yahoo.com> <CAPTjJmqtMhS8jp3D+SNiOAp-v9QzP5tkQzCqmO_Re7oLepOWwQ@mail.gmail.com>
Date: Mon, 2 Apr 2012 04:46:41 -0700 (PDT)
From: Yingjie Lan <lanyjie@yahoo.com>
Subject: Re: string interpolation for python
To: "python-list@python.org" <python-list@python.org>
In-Reply-To: <CAPTjJmqtMhS8jp3D+SNiOAp-v9QzP5tkQzCqmO_Re7oLepOWwQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
Precedence: list
Reply-To: Yingjie Lan <lanyjie@yahoo.com>
Newsgroups: comp.lang.python
Message-ID: <mailman.1210.1333367209.3037.python-list@python.org>
Lines: 33
NNTP-Posting-Host: 2001:888:2000:d::a6
Xref: csiph.com comp.lang.python:22459

>=A0=0A=0A>>>>  "Are you "+name+"?"=0A> =0A> That allows arbitrary expressi=
ons and everything.=0A>=A0=0A=0ATo make that work for any type, you need:=
=0A=0A>>> "Are you "+ str(name) + "?"=0A=0AAnother concern is performance.=
=0A=0AYou are absolutely right, they are=A0=0Aequivalent in that both are e=
xpressions.=0AAs long as people start to realize that=0Adynamic strings are=
 expressions,=0Athere is no magic in it any more.=0A=0AAnd allowing express=
ions in those=0Adynamic strings=A0would make sense=A0=0Asince=A0they are of=
 the same sort.=0A=0A>>> d"sin($x$) =3D $ sin(x):0.3f $"=0A=0Ais equivalent=
 to the expression of=0A=0A>>> "sin(%s"%x + ")=3D %0.3f"%sin(x)=0A=0ACompar=
ing th e two, I would say the latter=0Ais more computer friendly while=A0=
=0Athe former, more human friendly.=0A=0AIf the computed result is only to =
be=0Aused in formatting the string, it would=0Abe nice to save an assignmen=
t stmt.=0A=0A=0A>> =0A>>  Almost as terse, but not as readable, especially=
=0A>>  when there are many=A0parts to substitute --=0A>>  the coder and rea=
der need to be careful=0A>>  to=A0make sure the sequence is correct.=0A> =
=0A> I quite like this notation, personally. It's convenient, and is=0A> su=
pported (with variants) in quite a few C-derived languages (and, in=0A> spi=
te of the massive syntactic differences, Python does have C=0A> heritage).=
=0A=0ASure, once you get used to it, it would be harder to stop it=0A=A0the=
 harder it is :). That's part of human nature, anyway.=0A=0A=0A>>  Why the =
Python community is so=0A>>  hostile to new things now?=0A>>  Python has me=
rits,=0A>>  but it is far from being perfect.=0A> =0A> Hey now, no need to =
get defensive :) Thing is, it's up to you to=0A> demonstrate that your prop=
osal justifies itself. You're proposing to=0A> create a massive backward-co=
mpatibility issue, so you need to prove=0A> that your new way of formatting=
 strings is sufficiently awesome to be=0A> able to say "Well, you need Pyth=
on 3.4+ to use this".=0A> =0A=0A=0AOK. I have put it out as is. I trust peo=
ple knows good things.=0A=0AI would simply say: this new way is much more s=
imple=A0=0Aand much more powerful. And there is no security issues=0Aas lon=
g as you don't use the evil eval to evaluate expressions,=0Awhich is always=
 a security issue.=0A=0AIt is new, and has no compatibility issues with old=
 ways at all.=0AIn syntax, all you need is to allow d"...", which clearly w=
on't=0Aaffect any old ways of business.=0A=0ACheers,=0A=0AYingjie