Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!cs.uu.nl!news0.firedrake.org!news.xcski.com!ncf.ca!not-for-mail
From: "Colin J. Williams" <cjw@ncf.ca>
Newsgroups: comp.lang.python
Subject: Re: Yet another Python textbook
Date: Thu, 22 Nov 2012 07:24:38 -0500
Organization: National Capital Freenet, Ottawa, Ontario, Canada
Lines: 66
Sender: fn681@dsl-153-214.b2b2c.ca
Message-ID: <50AE1986.2080605@ncf.ca>
References: <CAB89DN0nusHZU32zP5UbTSUH8P7aXJomssBT-Jge7LEhaOtphg@mail.gmail.com> <CALwzid=3b_Gv3XR5iYvo7Pc0ZjXERB60daT9AjVoOG1OAP9vNg@mail.gmail.com> <CAB89DN0M5NzpoLRtcXRtM4Vs4xrOfw0wZq64GkU-DKy=Ei8HJQ@mail.gmail.com> <mailman.34.1353398989.29569.python-list@python.org> <31a82817-8c9b-4dd2-a468-89d8d081fd1b@googlegroups.com> <mailman.96.1353445247.29569.python-list@python.org> <50AD0962.5080002@ncf.ca> <mailman.180.1353536254.29569.python-list@python.org>
NNTP-Posting-Host: dsl-153-214.b2b2c.ca
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Trace: theodyn.ncf.ca 1353587080 3139 66.158.153.214 (22 Nov 2012 12:24:40 GMT)
X-Complaints-To: complaints@ncf.ca
NNTP-Posting-Date: 22 Nov 2012 12:24:40 GMT
Cc: rosuav@gmail.com
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/17.0 Thunderbird/17.0
In-Reply-To: <mailman.180.1353536254.29569.python-list@python.org>
Xref: csiph.com comp.lang.python:33798

 From Yet another Python textbook
On 21/11/2012 5:17 PM, Chris Angelico wrote:
> On Thu, Nov 22, 2012 at 4:03 AM, Colin J. Williams <cjw@ncf.ca> wrote:
>> On 20/11/2012 4:00 PM, Chris Angelico wrote:
>>> To the OP: jmf has an unnatural hatred of Python 3.3 and PEP 393
>>> strings. Take no notice; the rest of the world sees this as a huge
>>> advantage. Python is now in a VERY small group of languages (I'm aware
>>> of just one other) that have absolutely proper Unicode handling *and*
>>> efficient string handling.
>>>
>>> ChrisA
>>>
>> It's interesting to see that someone else finds the format function to be a
>> pain.  Perhaps the problem lies with the documentation.
>
> Hang on, what? I'm not sure where the format function comes in. I was
> referring to the underlying representation.
The OP wrote:
   "The absurd flexible string representation has practically
borrowed the idea to propose once Python has a teaching tool."

I perhaps stretched this to refer specifically on one aspect, formatting 
in my comment.
>
> That said, though, I'm just glad that %-formatting is staying. It's an
> extremely expressive string formatting method, and exists in many
> languages (thanks to C's heritage). Pike's version is insanely
> powerful, Python's is more like C's, but all three are compact and
> convenient.
>
> str.format(), on the other hand, is flexible. It strikes me as rather
> more complicated than a string formatting function needs to be, but
> that may be a cost of its flexibility.
>
> ChrisA

Yes is is complicated.

 From my reading of the docs, it seems to me that the three following 
should be equivalent:

   (a) formattingStr.format(values)
with
   (b) format(values, formattingStr)
or
   (c) tupleOfValues.__format__(formattingStr

Example:
print('{:-^14f}{:^14d}'.format(-25.61, 95 ))
print(format((-25.61, 95), '{:-^14f}{:^14d}'))
(-25.61, 95 ).__format__('{:-^14f}{:^14d}')

The second fails, perhaps because values can only be a single value.
The third fails, the reason is unclear.

Steven D'Aprano earlier said that a better diagnostic tool is planned 
for Python 3.4.

Should we retreat to %-formatting for now?

Colin W.



>