On 12/05/2011 04:51, Chris Angelico wrote:
On Thu, May 12, 2011 at 7:02 AM, Ianhobso...@gmail.com wrote:
In the real world lists of zero items do not exist.
You don't go shopping with a shopping list of zero items.
Actually, yes you do. You maintain your shopping list between trips;
whenever
Am 11.05.2011 23:02 schrieb Ian:
On 11/05/2011 20:13, Hans Georg Schaathun wrote:
Lists do not have truth values in the
application domain, and therefore truth values in the
implementation domain is complicated.
Exactly. Its just a convention. If it exists, its true, if if doesn't
its
Gregory Ewing greg.ew...@canterbury.ac.nz writes:
Hans Georg Schaathun wrote:
0 is a number as real and existent as any other,
one would think that the empty list is also as real and existent as
any other list.
0 does have some special properties, though, such as
being the additive
On 5/21/2011 7:46 AM John J Lee said...
Gregory Ewinggreg.ew...@canterbury.ac.nz writes:
Hans Georg Schaathun wrote:
0 is a number as real and existent as any other,
one would think that the empty list is also as real and existent as
any other list.
0 does have some special properties,
On 5/21/2011 10:46 AM, John J Lee wrote:
In the absence of an explicit interface declaration (have any standards
emerged for that in Python 3, BTW?), the use of len() does give you some
information about the interface, which sometimes makes it easier to
change the function.
I'm sure you fully
On Sat, 21 May 2011 15:46:01 +0100, John J Lee wrote:
In the absence of an explicit interface declaration (have any standards
emerged for that in Python 3, BTW?), the use of len() does give you some
information about the interface, which sometimes makes it easier to
change the function.
Er,
On Sun, May 22, 2011 at 11:02 AM, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
On Sat, 21 May 2011 15:46:01 +0100, John J Lee wrote:
Er, yes? But in any realistic example (your trivial function xyzzyx below
is not very realistic) you'll almost certainly get additional hints in
On May 22, 1:11 am, Terry Reedy tjre...@udel.edu wrote:
I agree that the domain of a function should be defined from the start
(and only expanded in the future).
I dont understand...
I dont always write correct code -- otherwise called 'a bug' -- though
I never let the damn bug lose
On Sun, May 22, 2011 at 1:02 PM, rusi rustompm...@gmail.com wrote:
Why is the C library in linux called libc6 and not just libc?
I assume you mean this? http://www.linux-m68k.org/faq/glibcinfo.html
When you dynamically link against a shared object, you save on
executable size, but you have to
On May 22, 8:52 am, Chris Angelico ros...@gmail.com wrote:
On Sun, May 22, 2011 at 1:02 PM, rusi rustompm...@gmail.com wrote:
Why is the C library in linux called libc6 and not just libc?
I assume you mean this?http://www.linux-m68k.org/faq/glibcinfo.html
Ha Ha! Thanks for that link! I
On Sun, May 22, 2011 at 2:32 PM, rusi rustompm...@gmail.com wrote:
Recently on the emacs list there was a big flame-fest because the
behavior (aka interface) of return/newline changed.
The argument for change: Can we have emacs behave a little more like a
21st century application?
Against:
On May 16, 2:36 am, Terry Reedy tjre...@udel.edu wrote:
On 5/15/2011 1:33 PM, rusi wrote:
On May 15, 10:07 am, Steven D'Apranosteve
+comp.lang.pyt...@pearwood.info wrote:
I'm afraid I don't understand what you mean. Can you explain please, what
properties of first class booleans do you
On May 15, 10:07 am, Steven D'Aprano steve
+comp.lang.pyt...@pearwood.info wrote:
I'm afraid I don't understand what you mean. Can you explain please, what
properties of first class booleans do you think are missing from Python?
Dijkstra's writings I alluded to, take a logic/math line to
On 5/15/2011 1:33 PM, rusi wrote:
On May 15, 10:07 am, Steven D'Apranosteve
+comp.lang.pyt...@pearwood.info wrote:
I'm afraid I don't understand what you mean. Can you explain please, what
properties of first class booleans do you think are missing from Python?
Given the usual CS definition
On Sun, 15 May 2011 10:33:38 -0700, rusi wrote:
On May 15, 10:07 am, Steven D'Aprano steve
+comp.lang.pyt...@pearwood.info wrote:
I'm afraid I don't understand what you mean. Can you explain please,
what properties of first class booleans do you think are missing from
Python?
[snip]
I'm
rusi wrote:
But on further examination (with Leibniz law above) Dijkstra's 23 =
True will work consistently in all contexts but [1,2,3] = True will
work sometimes and fail sometimes.
It would have to be written 23 == True; [1,2,3] == True; otherwise,
...
+1 QOTW
--
On 5/15/2011 5:36 PM, Terry Reedy wrote:
On 5/15/2011 1:33 PM, rusi wrote:
Dijkstra's writings I alluded to,
at
http://www.cs.utexas.edu/users/EWD/transcriptions/EWD10xx/EWD1070.html
Acquiring that familiarity requires what in these financial times is
known as intellectual investment; you
Steven D'Aprano wrote:
I'm afraid I don't understand what you mean. Can you explain please,
http://www.informatik.uni-bremen.de/agbkb/lehre/ws06-07/casl/slides/Datatypes-II.pdf
Geeze, I wonder if software is mathematics
kind regards,
m harris
--
On Friday 13 May 2011 18:47:50 Hans Georg Schaathun wrote:
On Thu, 12 May 2011 23:20:20 +1000, Chris Angelico
ros...@gmail.com wrote:
: Writing a program requires expertise both in programming
snip...
And the main difference here, is that the civil engineers
have a much better language
I have been scolded off-list for pursuing a discussion that has
nothing to do with python.
So I continue a bit gingerly :-) and will stop when others feel this
is useless/irrelevant/whatever.
Steven wrote:
I'm afraid I didn't find your discussion about reification, Platonism and
linguistics
On Fri, May 13, 2011 at 10:47 PM, harrismh777 harrismh...@charter.net wrote:
http://www.inf.ed.ac.uk/teaching/courses/inf1/fp/
http://www.cs.ou.edu/~rlpage/fpclassSpring97/
There are lots of these... the two above afaik are still doing this at the
entry level... ... supposedly, these
On Thu, 12 May 2011 23:46:12 -0700, rusi wrote:
Mathematics has existed for millenia. Hindu-arabic numerals (base-10
numbers) have been known for about one millennium
The boolean domain is only a 100 years old. Unsurprisingly it is not
quite 'first-class' yet: See
On May 14, 12:39 pm, Steven D'Aprano steve
+comp.lang.pyt...@pearwood.info wrote:
On Thu, 12 May 2011 23:46:12 -0700, rusi wrote:
Mathematics has existed for millenia. Hindu-arabic numerals (base-10
numbers) have been known for about one millennium
The boolean domain is only a 100 years
On 07/05/2011 02:43, Jon Clements wrote:
On May 7, 12:51 am, Ian Kellyian.g.ke...@gmail.com wrote:
On Fri, May 6, 2011 at 4:21 PM, Philip Semanchukphi...@semanchuk.com wrote:
What if it's not a list but a tuple or a numpy array? Often I just want to
iterate through an element's items and I
On Sat, May 14, 2011 at 5:45 PM, rusi rustompm...@gmail.com wrote:
And then we get the interesting result that
(True = True) is False
How does this work? In Python, the = sign is illegal there, and if you
mean True == True, then it's True (obviously), which is not False.
Chris Angelico
--
On Fri, May 13, 2011 at 10:34 PM, Gregory Ewing
greg.ew...@canterbury.ac.nz wrote:
rusi wrote:
Dijkstra's problem (paraphrased) is that python, by choosing the
FORTRAN alternative of having a non-first-class boolean type, hinders
scientific/mathematical thinking/progress.
Python doesn't
In article mailman.1549.1305383294.9059.python-l...@python.org,
David Robinow drobi...@gmail.com wrote:
On Fri, May 13, 2011 at 10:34 PM, Gregory Ewing
greg.ew...@canterbury.ac.nz wrote:
rusi wrote:
Dijkstra's problem (paraphrased) is that python, by choosing the
FORTRAN alternative of
On May 14, 6:42 pm, Chris Angelico ros...@gmail.com wrote:
On Sat, May 14, 2011 at 5:45 PM, rusi rustompm...@gmail.com wrote:
And then we get the interesting result that
(True = True) is False
How does this work? In Python, the = sign is illegal there, and if you
mean True == True, then
On Sun, May 15, 2011 at 1:47 AM, rusi rustompm...@gmail.com wrote:
So since
[1,2,3] is one way of writing True (lets call it True3)
and [1,2] is another (call it True2)
then we have True3 == True2 is False
But since according to Steven (according to Python?) True3 *is the
same* as True2
we
On May 14, 8:55 pm, Chris Angelico ros...@gmail.com wrote:
On Sun, May 15, 2011 at 1:47 AM, rusi rustompm...@gmail.com wrote:
So since
[1,2,3] is one way of writing True (lets call it True3)
and [1,2] is another (call it True2)
then we have True3 == True2 is False
But since according
On 5/14/2011 3:39 AM, Steven D'Aprano wrote:
Th money-quote as regards using arbitrary objects in truth tests:
[quote]
All this changed with the introduction of the two-element
boolean domain {true, false} which provides the vocabulary
needed to assign values to boolean
On 5/14/2011 3:45 AM, rusi wrote:
(True = True) is False
is a syntax error ;-)
and 'True = True' is a (useless) statement,
and statements do not have boolean values,
and 'True == True' *is* True, which is to say,
((True == True) is False) is False.
--
Terry Jan Reedy
--
On 5/14/2011 1:43 PM, rusi wrote:
But it seems you did not get the moral? Spelt out: Beware of lossy
compression!
[Which is also the moral of my 'proof']
I get it now. As I suggested in response to Stephen, [] and [1] spell
False and True only in boolean contexts (if/while headers) where
rusi rustompm...@gmail.com writes:
[Steven quote]
In Python, [1, 2, 3] is another way of writing true, and [] is another
way of writing false. Similarly with any other arbitrary objects. The
only things that bools True and False are good for are:
snipped
[end Steven quote]
On May 15, 4:26 am, Ben Finney ben+pyt...@benfinney.id.au wrote:
rusi rustompm...@gmail.com writes:
[Steven quote]
In Python, [1, 2, 3] is another way of writing true, and [] is another
way of writing false. Similarly with any other arbitrary objects. The
only things that bools True and
On Sat, 14 May 2011 00:45:29 -0700, rusi wrote:
On May 14, 12:39 pm, Steven D'Aprano steve
+comp.lang.pyt...@pearwood.info wrote:
On Thu, 12 May 2011 23:46:12 -0700, rusi wrote:
Mathematics has existed for millenia. Hindu-arabic numerals (base-10
numbers) have been known for about one
On Sat, 14 May 2011 19:41:32 -0700, rusi wrote:
The python entities: {True, False} are not an exact (isomorphic) model
for the semantic boolean domain {true, false} (which is needed for
example to explicate the semantics of if while etc) Which is to say the
boolean type in python is not
Mathematics has existed for millenia.
Hindu-arabic numerals (base-10 numbers) have been known for about one
millennium
The boolean domain is only a 100 years old.
Unsurprisingly it is not quite 'first-class' yet: See
http://www.cs.utexas.edu/users/EWD/transcriptions/EWD10xx/EWD1070.html
[Lifted
On Thu, May 12, 2011 at 11:46 PM, rusi rustompm...@gmail.com wrote:
snip
The boolean domain is only a 100 years old.
Unsurprisingly it is not quite 'first-class' yet: See
It is nowadays. Every halfway-mainstream language I can think of has
an explicit boolean datatype. Heck, as of C99, even C
On Thu, 12 May 2011 23:20:20 +1000, Chris Angelico
ros...@gmail.com wrote:
: Writing a program requires expertise both in programming and in the
: purpose for which it's being written. Ultimately, a programmer is a
: translator; without proper comprehension of the material he's
:
On May 13, 1:02 pm, Chris Rebert c...@rebertia.com wrote:
On Thu, May 12, 2011 at 11:46 PM, rusi rustompm...@gmail.com wrote:
The boolean domain is only a 100 years old.
Unsurprisingly it is not quite 'first-class' yet: See
It is nowadays. Every halfway-mainstream language I can think of
ru...@yahoo.com wrote:
http://www.codinghorror.com/blog/2006/07/separating-programming-sheep-from-non-programming-goats.html
A later paper by the same authors...
(http://www.eis.mdx.ac.uk/research/PhDArea/saeed/paper3.pdf)
These papers are fascinating reading, not only for philosophy sake
On Fri, May 13, 2011 at 1:41 PM, harrismh777 harrismh...@charter.net wrote:
On the other hand, kids today are dumped into a first comp sci course in
programming and plopped in-front of a Hugs interactive shell and then are
expected to learn programming and be successful by trying to grasp pure
Ian Kelly wrote:
Well, at least Haskell is probably better as an introductory language
than Lisp or Scheme. But what schools actually do this?
http://www.cs.kent.ac.uk/teaching/resources/haskell/HugsResources.html
http://research.cs.queensu.ca/home/cisc260/2010w/haskell.html
These are
On Fri, May 13, 2011 at 6:48 PM, harrismh777 harrismh...@charter.net wrote:
Ian Kelly wrote:
Well, at least Haskell is probably better as an introductory language
than Lisp or Scheme. But what schools actually do this?
http://www.cs.kent.ac.uk/teaching/resources/haskell/HugsResources.html
Ian Kelly wrote:
If a math major comes to you wanting to learn some
programming for theorem-proving, bearing in mind that they probably
aren't interested in learning more than a single language,
I would question whether theorem-proving is the *only*
thing they will ever want to do with a
harrismh777 wrote:
... and I'm also lumping two other languages into this 'category'...
namely, Scheme, and Erlang.
Scheme isn't really a functional language, though. You can
use a subset of it in a functional way, but it doesn't have
the sort of built-in support for pattern matching and
rusi wrote:
Dijkstra's problem (paraphrased) is that python, by choosing the
FORTRAN alternative of having a non-first-class boolean type, hinders
scientific/mathematical thinking/progress.
Python doesn't have the flaw that Dijkstra was talking about.
Fortran's flaw wasn't so much the lack of
Ian Kelly wrote:
Well, at least Haskell is probably better as an introductory language
than Lisp or Scheme. But what schools actually do this?
http://www.inf.ed.ac.uk/teaching/courses/inf1/fp/
http://www.cs.ou.edu/~rlpage/fpclassSpring97/
There are lots of these... the two above
On 11 May 2011 21:47:27 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: On Wed, 11 May 2011 20:13:35 +0100, Hans Georg Schaathun wrote:
: One principle of object oriented programming is to bestow the objects
: with properties reflecting known properties from the domain
On Wed, 11 May 2011 20:16:01 -0700 (PDT), alex23
wuwe...@gmail.com wrote:
: Hans Georg Schaathun h...@schaathun.net wrote:
: Revolutionary indeed, so why don't we exploit the revolution
: and write the programs to be as accessible as possible?
:
: Where do you draw the line, though?
I said
On Thu, 12 May 2011 17:44:07 +1200, Gregory Ewing
greg.ew...@canterbury.ac.nz wrote:
: Roy Smith wrote:
: Hans Georg Schaathun h...@schaathun.net wrote:
: If both are numbers, they are converted to a common type. Otherwise,
: objects of different types always compare unequal
Actually, I did
On Wed, 11 May 2011 22:53:45 -0500, harrismh777 wrote:
alex23 wrote:
through intuitive language skills. Why not?
Because the vast majority of them don't seem to want to be bothered?
That could very well be... but I have a hope for them. I honestly think
its not because they don't want to
On Thu, 12 May 2011 01:49:05 -0400, D'Arcy J.M. Cain
da...@druid.net wrote:
: That's not programming. That's using a canned app that a programmer
: wrote that takes your unstructured input and does something useful with
: it. Spreadsheets are a primitive example of that. Google is a more
:
On 11 May 2011 21:42:10 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: *Potentially* different tests. Which is exactly the point. Given an
: arbitrary object, the developer doesn't know what test is appropriate.
: Should I write len(x) == 0 or list(x) == [] or x.next is
On Wed, 11 May 2011 20:31:45 -0700 (PDT), alex23
wuwe...@gmail.com wrote:
: On May 12, 7:24 am, harrismh777 harrismh...@charter.net wrote:
: We need to move away from 'canned apps' to a new day where
: the masses can sit down to their computer and solve new problems with it
: through
Hans Georg Schaathun h...@schaathun.net writes:
On Wed, 11 May 2011 20:31:45 -0700 (PDT), alex23
wuwe...@gmail.com wrote:
: On May 12, 7:24 am, harrismh777 harrismh...@charter.net wrote:
: We need to move away from 'canned apps' to a new day where
: the masses can sit down to their
On Thu, 12 May 2011 16:46:38 +1000, Ben Finney
ben+pyt...@benfinney.id.au wrote:
: Hans Georg Schaathun h...@schaathun.net writes:
:
: On Wed, 11 May 2011 20:31:45 -0700 (PDT), alex23
:wuwe...@gmail.com wrote:
: : On May 12, 7:24 am, harrismh777 harrismh...@charter.net wrote:
: : We
Hans Georg Schaathun h...@schaathun.net writes:
On Thu, 12 May 2011 16:46:38 +1000, Ben Finney
ben+pyt...@benfinney.id.au wrote:
: Hans Georg Schaathun h...@schaathun.net writes:
:
: On Wed, 11 May 2011 20:31:45 -0700 (PDT), alex23
:wuwe...@gmail.com wrote:
: : On May 12, 7:24
In article 931adaf9g...@mid.individual.net,
Gregory Ewing greg.ew...@canterbury.ac.nz wrote:
Roy Smith wrote:
If both are numbers, they are converted to a common type. Otherwise,
objects of different types always compare unequal
That's just the default treatment for unrelated types that
On Thu, May 12, 2011 at 4:21 PM, Hans Georg Schaathun h...@schaathun.net
wrote:
On Thu, 12 May 2011 01:49:05 -0400, D'Arcy J.M. Cain
da...@druid.net wrote:
: That's not programming. That's using a canned app that a programmer
: wrote that takes your unstructured input and does something
On Thu, 12 May 2011 22:16:10 +1000, Chris Angelico
ros...@gmail.com wrote:
: Anyone can join. Not everyone wants to join. Me, I'm happy here as a
: priest of the software industry, and I have no desire to become a
: priest of, say, automotive engineering or concrete pouring. Would an
:
On Thu, May 12, 2011 at 10:43 PM, Hans Georg Schaathun h...@schaathun.net
wrote:
On Thu, 12 May 2011 22:16:10 +1000, Chris Angelico
ros...@gmail.com wrote:
: Anyone can join. Not everyone wants to join. Me, I'm happy here as a
: priest of the software industry, and I have no desire to
Chris Angelico wrote:
On Thu, May 12, 2011 at 7:02 AM, Ian hobso...@gmail.com wrote:
In the real world lists of zero items do not exist.
You don't go shopping with a shopping list of zero items.
Actually, yes you do. You maintain your shopping list between trips;
whenever you need something,
On Fri, May 13, 2011 at 12:02 AM, Ethan Furman et...@stoneleaf.us wrote:
Chris Angelico wrote:
On Thu, May 12, 2011 at 7:02 AM, Ian hobso...@gmail.com wrote:
In the real world lists of zero items do not exist.
You don't go shopping with a shopping list of zero items.
Actually, yes you do.
On 05/12/2011 12:13 AM, Steven D'Aprano wrote:
[snip]
http://www.codinghorror.com/blog/2006/07/separating-programming-sheep-from-non-programming-goats.html
Shorter version: it seems that programming aptitude is a bimodal
distribution, with very little migration from the can't program hump
On 5/11/2011 8:26 AM, Roy Smith wrote:
I conclude that li == [] should have returned False. Either I'm not
understanding things correctly, or this is a bug.
The doc is wrong (and not only on this). I am working on a report with
suggested fixes. Will post number when finish.
--
Terry Jan
On 5/12/2011 3:37 PM, Terry Reedy wrote:
On 5/11/2011 8:26 AM, Roy Smith wrote:
I conclude that li == [] should have returned False. Either I'm not
understanding things correctly, or this is a bug.
The doc is wrong (and not only on this). I am working on a report with
suggested fixes. Will
On Thu, 12 May 2011 07:36:27 -0400, Roy Smith wrote:
In article 931adaf9g...@mid.individual.net,
Gregory Ewing greg.ew...@canterbury.ac.nz wrote:
Roy Smith wrote:
If both are numbers, they are converted to a common type. Otherwise,
objects of different types always compare unequal
On 07 May 2011 02:51:50 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: On Fri, 06 May 2011 14:57:21 -0700, scattered wrote:
:
: is there any problem with
:
: (3) if li == []:
:
: ?
:
: Seems to work when I test it and seems to clearly test what you are
: trying
On 07 May 2011 02:49:53 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: On Fri, 06 May 2011 16:05:09 -0400, Adam Tauno Williams wrote:
:
: I'd never accept code like if not x as an empty test.
:
: So much the worse for you then.
:
: The point of the if x idiom is that
In this case, the interpretation of an arbitrary object as a boolean
is peculiar for python. An empty list is a real, existing object, and
the supposition that [] be false is counter-intuitive. It can be
learnt, and the shorthand may be powerful when it is, but it will
confuse many readers.
On Sat, 07 May 2011 21:57:13 -0700, Ethan Furman
et...@stoneleaf.us wrote:
: If you're going to use a language, and use it well, you have to learn
: how that language works.
And if the world evolves around the compiler and you, that advice
suffices.
However, programming is often as much
On Wed, 11 May 2011 11:48:16 +0200, Laurent Claessens wrote:
Once I wrote something like:
def f(x=None):
if x:
print x
else:
print I have no value
The caller of that function was something like f(cos(2*theta)) where
theta come from some computations.
Well.
I believe you are grossly oversimplifying whatever code you had. Using
the definition of f from above:
theta = math.pi/4
f(math.cos(2*theta))
6.12303176911e-17
Yes: its oversimplifued. The angle come from a normal vector of a curve
and so on In particular, I was using Sage; the
I believe you are grossly oversimplifying whatever code you had. Using
the definition of f from above:
theta = math.pi/4
f(math.cos(2*theta))
6.12303176911e-17
Yes: its oversimplifued. The angle come from a normal vector of a curve
and so on In particular, I was using Sage; the
On Wed, 11 May 2011 10:02:42 +0100, Hans Georg Schaathun wrote:
The problem with 'if x' is that it requires a much more detailed
understanding of python.
Much more detailed? Hardly.
Understanding that Python accepts any and all objects in truth-testing
concepts, and the rules thereof, is
On Wed, 11 May 2011 10:14:38 +0100, Hans Georg Schaathun wrote:
In this case, the interpretation of an arbitrary object as a boolean is
peculiar for python.
Incorrect. It is widespread among many languages. Programmers have been
writing conditional tests using arbitrary values since 1958
On Wed, 11 May 2011 11:47:42 +0100, Hans Georg Schaathun wrote:
On Sat, 07 May 2011 21:57:13 -0700, Ethan Furman
et...@stoneleaf.us wrote:
: If you're going to use a language, and use it well, you have to learn
: how that language works.
And if the world evolves around the compiler and
On 11 May 2011 13:36:02 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: In this case, the interpretation of an arbitrary object as a boolean is
: peculiar for python.
:
: Incorrect. It is widespread among many languages. Programmers have been
: writing conditional
On 11 May 2011 12:14:46 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: Not knowing that you can write if x instead of if x == [] is like not
: knowing that you can write
:
: elif condition
:
: instead of
:
: else:
: if condition
My concern was
On Wed, 11 May 2011 11:47:42 +0100
Hans Georg Schaathun h...@schaathun.net wrote:
However, programming is often as much about developing ideas in a large
and complex community, where perfect universal mastery of one language
is not an option, because half the community do not normally use that
On Wed, 11 May 2011 15:05:45 +0100
Hans Georg Schaathun h...@schaathun.net wrote:
What could elif mean other than else: if?
If run by an elf? Who knows. You do, of course, if you have learned
the basics of the language you are using.
if x could, for instance, mean if x is defined.
It could
On 11 May 2011 13:45:52 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: Do you think that we should avoid chained comparisons, class methods,
: closures, co-routines, decorators, default values to functions,
: delegation, doc tests, exceptions, factory functions,
On Thu, May 12, 2011 at 12:00 AM, Hans Georg Schaathun h...@schaathun.net
wrote:
The fact that you need to list language by language which objects
evaluate as false or equivalent to false illustrates that this has
to be learnt language by language. Allowing arbitrary objects is
one thing,
On Wed, 11 May 2011 10:33:51 -0400, D'Arcy J.M. Cain wrote:
Non-programmers should be able to program?
Wasn't that sort of the premise behind Visual Basic? I don't know if that
was the intention, but it sure was the result in a lot of cases.
--
Hans Georg Schaathun wrote:
On 11 May 2011 13:36:02 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: In this case, the interpretation of an arbitrary object as a boolean is
: peculiar for python.
:
: Incorrect. It is widespread among many languages. Programmers have
On Wed, 11 May 2011 15:05:45 +0100, Hans Georg Schaathun wrote:
My concern was with the reader and not the writer.
What could elif mean other than else: if?
It could mean Oh, the author has made a stupid typo, I better fix it.
It could mean What does the elif command do?
The first time I
On Thu, May 12, 2011 at 1:50 AM, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
On Wed, 11 May 2011 15:05:45 +0100, Hans Georg Schaathun wrote:
My concern was with the reader and not the writer.
What could elif mean other than else: if?
The first time I read Python code, I had
On Wed, 11 May 2011 15:34:28 +0100, Hans Georg Schaathun wrote:
On 11 May 2011 13:45:52 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: Do you think that we should avoid chained comparisons, class methods,
: closures, co-routines, decorators, default values to
On Wed, May 11, 2011 at 8:34 AM, Hans Georg Schaathun h...@schaathun.net
wrote:
E.g. Anyone who has used list/set comprehension in Z, haskell, set theory,
or whereever will understand python list comprehension immediately.
They would understand the underlying concept. But would somebody who
All of this just boils down to Python providing an implicit bool cast in
syntactic situations that expect conditional expressions, including if [1].
So if x: is equivalent to if bool(x). Perhaps that is the part that is
not immediately obvious, being implicit to Python conditional syntax.
I don't mean to insult anyone, but I've heard and read all the arguments
against Python's truth-testing, and they
don't impress me in the slightest. Most of them strike me as silly. The only
argument that carries any weight to me is
one which I haven't seen anyone raise:
if x: turns something
The audience I am concerned about is the ones who are over-educated
into using and having used a score of different meanings of the same
symbols. They will be used to their intuition being wrong when they
move into a new context. Being explicit will help them.
I find this argument to be
On Wed, 11 May 2011 10:33:51 -0400, D'Arcy J.M. Cain
da...@druid.net wrote:
: Non-programmers should be able to program?
That was not really what I suggested; I was primarily talking
about reading programs and commenting on formulæ and algorithms.
: Should non-doctors be able to doctor?
If
On 11 May 2011 16:26:40 GMT, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
: 1. My concern was not about clueless newbies. They need to
:learn. My concern is about experienced scientists and engineers who
:are simply new to python.
:
: Which makes them clueless newbies
On Thu, 12 May 2011 02:05:21 +1000, Chris Angelico
ros...@gmail.com wrote:
: In a Bourne shell script, if ends with fi... case ends with esac... so
: file would end with... hmm. Yeah, I think it's best to know the
: language you're trying to comprehend, and/or actually look at context
:
On Wed, 11 May 2011 10:27:49 -0400, D'Arcy J.M. Cain
da...@druid.net wrote:
: When did we come to the idea that people should be able to program in a
: language without actually learning it? The fact that Python comes so
: close to that possibility is nothing short of revolutionary.
On Wed, 11 May 2011 10:31:59 -0600, Ian Kelly
ian.g.ke...@gmail.com wrote:
: (x + 3 for x in xs if x % 2 == 1)
Interesting. Thanks. That might come in handy some time.
--
:-- Hans Georg
--
http://mail.python.org/mailman/listinfo/python-list
On Wed, 11 May 2011 13:50:54 -0400, Prasad, Ramit
ramit.pra...@jpmchase.com wrote:
: I find this argument to be flawed. Should I stop using built-in
: generators instead of range/xrange for looping through lists?
: Certainly for loops with loop counting are understood more widely
: than
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