The Python doc is relatively lousy, from content organization to the
tech writing quality.
I think i'll just post snippets of my comments as i find them. (and
feel like exposing)
Python doc:
http://python.org/doc/2.4/lib/comparisons.html
Quote:
Comparison operations are supported by all objects. They all have the
same priority (which is higher than that of the Boolean operations).
Comparisons can be chained arbitrarily; for example, x < y <= z is
equivalent to x < y and y <= z, except that y is evaluated only once
(but in both cases z is not evaluated at all when x < y is found to be
false).
--
Problem: “Comparison operations are supported by all objects.”
This is very vague and ambiguous.
The word “object” has generic English meaning as well might have
very technical meaning in a language. In Python, it does not have very
pronounced technical meaning. For example, there's a chapter in Python
Library Ref titled “2. Built-In Objects”, and under it a section
“2.1 Built-in Functions”. Apparently, functions can't possibly be
meant as a “object” for comparisons.
Now suppose we take the object in the sentence to be sensible items as
numbers, lists etc. The clause “supported by all objects” is
ambiguous. What is meant by “supported”?
--
Problem: They all have the same priority (which is higher than that of
the Boolean operations).
This sentence is very stupid, in multitude of aspects.
The “priority” referred to here means operator precedence.
It tries to say that the comparison operator has higher syntactical
connectivity than boolean operators. E.g. “False and False==False”
means “False and (False==False)” and not “(False and
False)==False”.
However, the “they” pronoun from the context of previous sentence,
refers to “the comparison operation”, not “operator”. So, it
conjures the reader to think about some “operation precedence”,
which in itself cannot be ruled out as nonsense depending on the
context. Very fucking stupid confusional writing.
And, from pure writing aspect, the sentence “...(which is ...)” is
some kind of a juvenile latch on. If the author intent to make that
point, say it in its own sentence. e.g. The comparison operators have
higher precedence than boolean operators. It would be better to not
mention this at all. For practical considerations, very rare is the
case of mixing boolean and comparison operators, and if so, parenthesis
are likely used and is indeed a good practice. The proper place for
operator precedence is a table list all such, giving a clear view, and
in some appendix of language spec.
--
Problem: Comparisons can be chained arbitrarily; for example, x < y <=
z is equivalent to x < y and y <= z, except that y is evaluated only
once (but in both cases z is not evaluated at all when x < y is found
to be false).
Drop the word “arbitrarily”. It has no meaning here.
the whole sentence is one fucked up verbiage of pell-mell thinking and
writing. Here's one example of better:
Comparisons can be chained, and is evaluated from left to right. For
example, x < y <= z is equivalent to (x < y) <= z.
With respect to documentation style, it is questionable that this
aspect needs to be mentioned at all. In practice, if programers need to
chain comparisons, they will readily do so. This is not out of ordinary
in imperative languages, and evaluation from left to right is also not
extraordinary to cost a mention.
--
Problem: <> and != are alternate spellings for the same operator. != is
the preferred spelling; <> is obsolescent
Very bad choice of term “spellings” -- not a standard usage for
computer language operators.
Better: “!=” can also be written as “<>”.
If “<>” is not likely to go out in future versions, don't even
mention about “preference”, because it has no effective meaning.
(if one wants to wax philosophical about “programing esthetics”, go
nag it outside of language documentation.)
In general, when something is obsolete or might go defunct in the
future, consider not even mentioning that construct. If necessary, add
it in a obscure place, and not adjacent to critical info. In many
places of Python documentation, this is breached.
--
This is just a quick partial analysis of one episode of incompetence i
see in Python docs in the past months i've had the pleasure to scan
here and there. A extreme pain in the ass.
I'm in fact somewhat surprised by this poor quality in writing. The
more egregious error is the hardware-oriented organization aka
technical drivel. But that i accept as common in imperative language
communities and in general the computing industry. But the poor quality
in the effectiveness and clarity of the writing itself surprised me. As
exhibited above, the writing is typical of programers, filled with
latch on sentences and unclear thinking. (they in general don't have a
clear picture of what they are talking about, and in cases they do,
they don't have the writing skills to express it effectively. (just as
a footnote: this writing problem isn't entirely the fault of programers
or Python doc writers. In part the English language (or in general
natural languages) are to blame, because they are exceptionally
illogical and really take years to master as a art by itself.))
The Python doc, though relatively incompetent, but the author have
tried the best. This is in contrast to documentations in unix related
things (unix tools, perl, apache, and so on etc), where the writers
have absolutely no sense of clear writing, and in most cases don't give
a damn and delight in drivel thinking of it as literary. A criminal of
this sort that does society huge damage is Larry Wall and the likes of
his cohorts in the unix community. (disclaimer: this is a piece of
opinion.)
addendum: quality writing takes time. Though, the critical part lies
not in the mastery of writing itself, but in clarity of thinking of
what exactly one wants to say. So, next time you are writing a tech
doc, first try to have a precise understanding of the object, and then
know exactly what is that you want to say about it, then the writing
will come out vastly better. If the precise understanding of the object
is not readily at hand (which is common and does not indicate
incompetence), being aware of it helps greatly in its exposition.
This and past critics on Python documentation and IT doc in general is
archived at
http://xahlee.org/Periodic_dosage_dir/t2/xlali_skami_cukta.html
Xah
···@xahlee.org
∑ http://xahlee.org/PageTwo_dir/more.html
Xah Lee wrote:
> The Python doc is relatively lousy, from content organization to the
> tech writing quality.
So write your own or fork the current one. I doubt if that's a problem.
Did you read Dive into Python?
--
John Small Perl scripts: http://johnbokma.com/perl/
Perl programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html
Xah Lee wrote:
> The Python doc is relatively lousy, from content organization to the
> tech writing quality.
>
> I think i'll just post snippets of my comments as i find them. (and
> feel like exposing)
The cross-posting idiot is back. Next he'll be posting his readings
from Richard Burton's _Arabian Nights_.
Xah, for you to think that Python is topical in the newsgroups to which
you posted, you must be sharing Karl Malbrain's cell at the loony bin.
Apologies to these various newsgroups, but I have no idea which one Xah
Lee actually reads or posts from. F'ups set.
In comp.lang.perl.misc Xah Lee <···@xahlee.org> wrote:
> The Python doc is relatively lousy, from content organization to the
> tech writing quality.
Which has precisely what to do with most of the groups to which you
cross-posted?
> Problem: They all have the same priority (which is higher than that of
> the Boolean operations).
> However, the ?they? pronoun from the context of previous sentence,
> refers to ?the comparison operation?, not ?operator?. So, it
> conjures the reader to think about some ?operation precedence?,
> which in itself cannot be ruled out as nonsense depending on the
> context. Very fucking stupid confusional writing.
The meaning is perfectly plain. By the way did you perhaps mean
'confusing' or 'confused'? I normally regard language flames
otiose but here, since you are trying to correct other people's
writing, fair game.
> And, from pure writing aspect, the sentence ?...(which is ...)? is
> some kind of a juvenile latch on. If the author intent to make that
Do you mean... 'if the author's intent is to make' or 'if the author
intends to'?
> point, say it in its own sentence. e.g. The comparison operators have
> higher precedence than boolean operators. It would be better to not
> mention this at all. For practical considerations, very rare is the
> case of mixing boolean and comparison operators, and if so, parenthesis
> are likely used and is indeed a good practice. The proper place for
Should that not be 'parentheses are likely to be used'?
It is not rare at all. Besides, little asides like this are an ideal
way to reinforce thoughts about operator preference and more helpful
then memorising a table.
> Problem: Comparisons can be chained arbitrarily; for example, x < y <=
> z is equivalent to x < y and y <= z, except that y is evaluated only
> once (but in both cases z is not evaluated at all when x < y is found
> to be false).
> Drop the word ?arbitrarily?. It has no meaning here.
I suggest you look up the meaning of the word.
> the whole sentence is one fucked up verbiage of pell-mell thinking and
> writing. Here's one example of better:
> Comparisons can be chained, and is evaluated from left to right. For
> example, x < y <= z is equivalent to (x < y) <= z.
You mean 'are evaluated'. Your rephrasing is also incomplete since
it doesn't note that z will not be evaulated if x < y is false.
> With respect to documentation style, it is questionable that this
> aspect needs to be mentioned at all. In practice, if programers need to
> chain comparisons, they will readily do so. This is not out of ordinary
> in imperative languages, and evaluation from left to right is also not
> extraordinary to cost a mention.
Really? In a reference manual such matters should be fully specified
regardless of what happens in other languages.
> Problem: <> and != are alternate spellings for the same operator. != is
> the preferred spelling; <> is obsolescent
> In general, when something is obsolete or might go defunct in the
> future, consider not even mentioning that construct. If necessary, add
> it in a obscure place, and not adjacent to critical info. In many
> places of Python documentation, this is breached.
Really? Actually it is very important to mention it in the correct
place in a reference manual. Do you understand the concept of
maintaining old code?
> I'm in fact somewhat surprised by this poor quality in writing. The
Really? The writing in the manual seems simple, straight-forward and
clear to me (knowing no Python). Unlike your writing.
> more egregious error is the hardware-oriented organization aka
> technical drivel.
What on earth does this mean?
> The Python doc, though relatively incompetent, but the author have
> tried the best. This is in contrast to documentations in unix related
> things (unix tools, perl, apache, and so on etc), where the writers
> have absolutely no sense of clear writing, and in most cases don't give
> a damn and delight in drivel thinking of it as literary.
I think that this is an excellent description of your own writing.
Axel
····@white-eagle.invalid.uk wrote:
>>The Python doc, though relatively incompetent, but the author have
Really, how could those morons even dream of creating a language,
and even writing docs to accompany it??
>>tried the best. This is in contrast to documentations in unix related
>>things (unix tools, perl, apache, and so on etc), where the writers
>>have absolutely no sense of clear writing, and in most cases don't give
>>a damn and delight in drivel thinking of it as literary.
Well, man-pages are at least coherent and precise.
It's not literature, it's technical documentation!
>
> I think that this is an excellent description of your own writing.
:)
To be sure, he's a stupid troll, but I think you shouldn't insult
him for being bad at English. I bet you (or most Western people
anyway) have trouble getting fluent in an Asian language. Imagine
the lingua franca were Chinese, non English...
Please stop cross-posting this stuff!
--
Keith Thompson (The_Other_Keith) ·····@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
Python doc “3.6.4 Mutable Sequence Types” at
http://python.org/doc/2.4/lib/typesseq-mutable.html
in which contains the documentation of the “sort” method of a list.
Quote:
--------------
.sort([cmp[, key[, reverse]]])
sort the items of s in place
(7), (8), (9), (10)
...
(8)
The sort() method takes optional arguments for controlling the
comparisons.
cmp specifies a custom comparison function of two arguments (list
items) which should return a negative, zero or positive number
depending on whether the first argument is considered smaller than,
equal to, or larger than the second argument: "cmp=lambda x,y:
cmp(x.lower(), y.lower())"
key specifies a function of one argument that is used to extract a
comparison key from each list element: "cmp=str.lower"
reverse is a boolean value. If set to True, then the list elements
are sorted as if each comparison were reversed.
In general, the key and reverse conversion processes are much faster
than specifying an equivalent cmp function. This is because cmp is
called multiple times for each list element while key and reverse
touch each element only once.
Changed in version 2.3: Support for None as an equivalent to omitting
cmp was added.
Changed in version 2.4: Support for key and reverse was added.
------------------
As a piece of documentation, this is a relatively lousy one.
The question Python doc writers need to ask when evaluating this piece
of doc are these:
* can a experienced programer (expert at several languages) who is new
to Python, and also have read the official Python tutorial, can he,
read this doc about ”sort”, and know exactly how to use it with all
the options?
* can this piece of documentation be rewritten fairly easily, so that
the answer to the previous question is a resounding yes?
To me, the answers to the above questions are No and Yes. Here are some
issues with the doc:
* in the paragraph about “Key”, the illustration given is:
“cmp=str.lower”. Shouldn't it be “key=str.lower”?
* This doc lacks examples. One or two examples will help a lot,
especially to less experienced programers. (which comprises the
majority of readers) In particular, it should give a full example of
using the cmp predicate and one with key.
* This doc fails to address what happens when the predicate and the
short cut version conflicts. e.g.
myList.sort(lambda x,y: cmp(x[0], y[0]), lambda x: str(x[0]), False )
* on the whole, the way this doc is written does not give a clear
picture of what exactly is happening (think of mathematics) with sort,
nor the roles of the supplied options, nor how to use them.
Quick remedy: add a examples of using cmp predicate. And a example
using “key” predicate. Add example of Using one of them and with
reverse. (the examples need not to come with much explanations. One
sentence annotation will do. )
Other than that, the way the doc is layed out with a terse table and
run-on footnotes (as appeared in other pages) is not inductive. For a
better improvement, there needs to be overhaul of the organization and
the attitude of the entire doc. The organization needs to be programing
based, as opposed to implementation or computer science based. (in this
regard, one can learn from the Perl folks). As to attitude, the writing
needs to be Python-as-is, as opposed to computer science framework.
I'll might have to give more details in the future, but I've made some
headway in this respect before; peruse:
http://xahlee.org/Periodic_dosage_dir/t2/xlali_skami_cukta.html
Xah
···@xahlee.org
∑ http://xahlee.org/PageTwo_dir/more.html
☄
On 28 Mar 2005 03:56:42 -0800, in comp.lang.c , "Xah Lee"
<···@xahlee.org> wrote:
>Python doc �3.6.4 Mutable Sequence Types� at
(whatever)
will you /please/ stop crossposting this python thread to comp.lang.c.
(FUP's set to exclude CLC, please respect this)
--
Mark McIntyre
CLC FAQ <http://www.eskimo.com/~scs/C-faq/top.html>
CLC readme: <http://www.ungerhu.com/jxh/clc.welcome.txt>