What is not objects in Python?

[process]

I have heard some criticism about Python, that it is not fully object-
oriented.

What is not an object in Python?

Why isn't len implemented as a str.len and list.len method instead of
a len(list) function?

[Steven D'Aprano]

On Mon, 29 Sep 2008 05:41:02 -0700, George Sakkis wrote:

For example I would be much less
opposed to len() being defined as, say, |x| if "|...|" was a valid
operator.

Arghh! No!!! |x| should be abs(x), not len(x). Just ask mathematicians
and physicists.

*wink*

Actually there's a serious point there. There aren't that many
unambiguous operators that are available on a standard keyboard that
(nearly) everyone can agree on.
--
Steven

[Terry Reedy]

Steven D'Aprano wrote:

On Mon, 29 Sep 2008 05:41:02 -0700, George Sakkis wrote:

>For example I would be much less
opposed to len() being defined as, say, |x| if "|...|" was a valid
operator.

Arghh! No!!! |x| should be abs(x), not len(x). Just ask mathematicians
and physicists.

It should be both, just as + is addition for numbers and concatenation
for sequences. Or we could have just one built-in -- size() instead of
abs() and len(). For non-sequence collections, size() would be better
than len() anyway.

tjr

[namekuseijin]

On 28 set, 15:29, process <circularf...@g mail.comwrote:

I have heard some criticism about Python, that it is not fully object-
oriented.

So what?

Why isn't len implemented as a str.len and list.len method instead of
a len(list) function?

Because postfix notation sucks. The natural way of spelling is
adjective+noun and verb+predicate. That's one of the reasons I like
Lisp better than Python.

[Roy Smith]

In article <ma************ *************** ***********@pyt hon.org>,
Terry Reedy <tj*****@udel.e duwrote:

It should be both, just as + is addition for numbers and concatenation
for sequences.

Actually, the math folks would argue that using + for concatenation is
wrong, since by normal math rules, + denotes a commutative operation.

Of course, the math folks think that i^2 = -1, so what do they know? All
right-thinking people know that j^2 = -1.

[Steven D'Aprano]

On Mon, 29 Sep 2008 21:03:07 -0700, namekuseijin wrote:

>Why isn't len implemented as a str.len and list.len method instead of a
len(list) function?

Because postfix notation sucks. The natural way of spelling is
adjective+noun and verb+predicate.

"Natural"?

You mean phrases like "heir apparent" and "worst choice imaginable" are
unnatural? To say nothing of languages like Spanish, Albanian, Italian,
Cornish, Vietnamese, Hebrew...

--
Steven

[Gabriel Genellina]

En Tue, 30 Sep 2008 01:03:07 -0300, namekuseijin <na**********@g mail.com>
escribió:

On 28 set, 15:29, process <circularf...@g mail.comwrote:

>Why isn't len implemented as a str.len and list.len method instead of
a len(list) function?

Because postfix notation sucks. The natural way of spelling is
adjective+noun and verb+predicate. That's one of the reasons I like
Lisp better than Python.

Well, "natural" for English-speaking people... Noun+adjective is usually
more "natural" In Spanish than the English word ordering.

Back to the original question, len(x) allows for a fast response without
paying the overhead of a name lookup and then a method call.
len(some_list) doesn't invoke some_list.__len __(), it just returns the
value stored somewhere in the list object; same for other built-in
objects. __len__ is searched as a last resort only.
The optimization could not be done if it were spelled x.len()

--
Gabriel Genellina

[Steve Holden]

Terry Reedy wrote:

Steven D'Aprano wrote:

>On Mon, 29 Sep 2008 05:41:02 -0700, George Sakkis wrote:

>>For example I would be much less
opposed to len() being defined as, say, |x| if "|...|" was a valid
operator.

Arghh! No!!! |x| should be abs(x), not len(x). Just ask mathematicians
and physicists.

It should be both, just as + is addition for numbers and concatenation
for sequences. Or we could have just one built-in -- size() instead of
abs() and len(). For non-sequence collections, size() would be better
than len() anyway.

And how are these "non-sequence collections" to be distinguished? And
how does size() differ from len() in that case?

regards
Steve
--
Steve Holden [phone] [phone]
Holden Web LLC http://www.holdenweb.com/

[Lie Ryan]

On Mon, 2008-09-29 at 21:03 -0700, namekuseijin wrote:

On 28 set, 15:29, process <circularf...@g mail.comwrote:

I have heard some criticism about Python, that it is not fully object-
oriented.

So what?

Why isn't len implemented as a str.len and list.len method instead of
a len(list) function?

Because postfix notation sucks. The natural way of spelling is
adjective+noun and verb+predicate. That's one of the reasons I like
Lisp better than Python.
--
http://mail.python.org/mailman/listinfo/python-list

Actually str.len and len(str) is just like saying "the string's length"
and "the length of the string". There is no difference between the two
except for personal preference. (I am no linguist-- not even a native
speaker of English --but I think there is a subtle difference on
emphasis, "the string's length" emphasizes on the length being string's
property, while "the length of the string" emphasizes on the length
itself, am I correct?)

[Steve Holden]

Steven D'Aprano wrote:

On Mon, 29 Sep 2008 21:03:07 -0700, namekuseijin wrote:

>>Why isn't len implemented as a str.len and list.len method instead of a
len(list) function?

Because postfix notation sucks. The natural way of spelling is
adjective+no un and verb+predicate.

"Natural"?

You mean phrases like "heir apparent" and "worst choice imaginable" are
unnatural?

They are certainly far from normal usage, as my dog yellow would be
certain to agree.

To say nothing of languages like Spanish, Albanian, Italian,
Cornish, Vietnamese, Hebrew...

It's long been a convention in the Western programming world to pretend
no other language than English and no other codes than ASCII exist.

The fact that Python is beginning to come to terms with Unicode is a
tribute to certain developers' persistence.

regards
Steve
--
Steve Holden [phone] [phone]
Holden Web LLC http://www.holdenweb.com/

[Steve Holden]

Steven D'Aprano wrote:

On Mon, 29 Sep 2008 21:03:07 -0700, namekuseijin wrote:

>>Why isn't len implemented as a str.len and list.len method instead of a
len(list) function?

Because postfix notation sucks. The natural way of spelling is
adjective+no un and verb+predicate.

"Natural"?

You mean phrases like "heir apparent" and "worst choice imaginable" are
unnatural?

They are certainly far from normal usage, as my dog yellow would be
certain to agree.

To say nothing of languages like Spanish, Albanian, Italian,
Cornish, Vietnamese, Hebrew...

It's long been a convention in the Western programming world to pretend
no other language than English and no other codes than ASCII exist.

The fact that Python is beginning to come to terms with Unicode is a
tribute to certain developers' persistence.

regards
Steve
--
Steve Holden [phone] [phone]
Holden Web LLC http://www.holdenweb.com/