[boB Stepp , on %i/%d and %f/%F]
> Hmm. I'm surprised this slight distinction was worth keeping two
> format codes that otherwise do the same thing. Is there an actual
> need for these due to Python being implemented behind the scenes in C?
The implementation is irrelevant to this. What is rele
[boB Stepp ]
> My Google-fu must be weak tonight.
Look here:
https://en.wikipedia.org/wiki/Printf_format_string
> I cannot find any discernible
> difference between '%f' % and '%F' %
> . Is there any or do they duplicate
> functionality? If the latter, why are there two ways of doing the
[Albert-Jan Roskam ]
> I just found a neat trick to free up an emergency stash of memory in
> a funtion that overrides sys.excepthook. The rationale is that all
> exceptions, including MemoryErrors will be logged.
> The code is below. My question: is that memory *guaranteed* to be
> freed right aft
[Luke Paireepinart]
>> This is really just a round-about way of using sets.
>> I don't really want to give a code-sample unless he's confirmed he's not
>> doing this as homework, but the set version is much more simple (shorter
>> code that makes more sense) and extremely quick as well. If you're
[kb1...@aim.com]
> I'm running a test to find what the experimental average of a d20 is,
I don't know what "a d20" is, but your code is picking integers
uniformly at random between 1 and 18 inclusive. The expected value is
therefore (1+18)/2.0 = 9.5.
> and came across a strange bug in my code.
>
[Angus Rogers, suffering eval-angst]
> ...
> On the other hand, so long as I AM only executing the function
> myself, I am no more at risk than I already am every single time
> I type a command into a Python interpreter, of any description.
> (A somewhat Existentialist thought, perhaps! Virtual su
[Angus Rodgers]
> ...
> If I started to agitate for changes to a marginal and little-used
> feature of the language within days of starting to learn it, might
> I not quickly earn a reputation as a crank? 8-P
If that's your /goal/, it would be easier to rant about some imagined
flaw in the ring o
[Angus Rodgers]
> I'm a little confused by: (i) the definition of the modulus and
> floor division functions for complex arguments;
Perhaps you're confused by the current definitions simply because they
don't make good sense.
> (ii) the fact that these functions for complex arguments are
> now "
[Alec Henriksen]
> How trustworthy is the "randomness" generated by the random module?
Python uses the Mersenne Twister algorithm for generating
pseudo-random numbers, and that's one of the highest-quality methods
known. You can read more about it, e.g., here:
http://en.wikipedia.org/wiki/Me
[Jeff Younker]
>> I'd suggest googling for 'trie'. Tries are method of
>> indexing sets of strings by prefix.
[R. Alan Monroe]
> Ah, will look it up.
Or you can puzzle it out from the attached program ;-)
> ...
> In the meantime, my current version is
> much improved - it caches rejects, so
[Dick Moores]
> ...
> But isn't there a PRECISE answer to my question?
Of course ;-)
> Or is it OT?
Well, it's really more a question about your machine's floating-point
hardware than about Python. Good explanations of exact limits for
IEEE-754 floating-point hardware can be found many places o
[Thomas]
> Earlier today I typed the following into my pythonwin interactive
> interpreter in windows xp:
>
> >>> int('7' * 10 ** 6)
>
> I expected either an error message
Unlikely, if your box has enough RAM to run WinXP :-)
> or it to get stuck and require me to stop the process manually.
Not
[Chris Lasher]
> My professor and advisor has been "inspired" by me to give Python a
> try. He's an avid Perl user, and challenged me with the following:
>
> What is the Python equivalent to perl -e ''?
The initally attractive but unsatisfying answer is:
python -c ''
The reason it's "unsatis
[Tim Peters]
>> If you want /true/ randomness, you can buy a certified hardware random
>> number generator, based on non-deterministic physical processes (like
>> timing radioactive decay, or measuring thermal noise).
[Terry Carroll]
> Why buy when you can borrow?:
Speed
[Dick Moores]
>>> Would this be a better random source than choice([0,1]), which uses
>>> random()?
[Tim Peters]
>> "Better" as measured against what criteria?
[Dick]
> I meant would it be closer to true randomness than random(), even if
> much slower?
D
[Dick Moores]
...
> I'm thinking that just for the hell of it I could use urandom() as a
> source of random decimal digits.
You could, yes.
> Or in a coin tossing program. Here's a list of 7817 '1's and 0's
> generated by urandom():
Note that the length of the list will vary from run to run. Si
[Geoframer]
> The last few days i've been learning python and have been doing this by
> trying to solve problems for a programming competition.
I assume you're talking about:
http://www.spoj.pl/problems/FCTRL/
If so, you'll note that I'm tied for the fastest Python solution there ;-)
The /g
[Tim Peters]
>> You would in this case, and that would be wrong. In fp you'd get an
>> approximation to the exact n * (1./5 + 1./5**2 + ...) == n/4. (use
>> the rule for the sum of an infinite geometric series). For example,
>> that way you'd compute that 4
[Tim Peters]
>> For a fun :-) exercise, prove that the number of trailing zeroes in n!
>> is the sum, from i = 1 to infinity, of n // 5**i (of course as soon as
>> you reach a value of i such that n < 5**i, the quotient is 0 at that i
>> and forever after).
>>
>
[Dick Moores, computes 100 factorial as
9332621544394415268169923885626670049071596826438162146859296389521753229915608941463976156518286253697920827223758251185210916864
but worries about all the trailing zeros]
> Yes, I'm sure you are. I'd forgotten about all tho
[Kermit Rose]
> My last email to you bounced.
>
>
> Why?
>
> From: [EMAIL PROTECTED]
> Date: 06/06/06 20:30:49
> To: [EMAIL PROTECTED]
> Subject: The results of your email commands
>
>
> The results of your email command are provided below. Attached is your
> original message.
>
> - Unprocessed:
>
es a row #, col #, and diag #.
>
> Scratching your head over how to number the diagonals I'll leave to you.
> They counted 30 diagonals, so if you come up with a different count, you
> either have an original approach or have blundered somewhere.
>
> (Hopefully that was the k
[Tim Peters]
>> That "should work", provided there aren't differences in whitespace
>> that are invisible to us in this medium. For example, if, in your
>> source file, there's actually a (one or more) trailing space on your
>> line of expected output,
[Don Taylor]
> I am trying to use Doctest and am having trouble using the ellipsis
> feature when trying to match an object reference.
>
> Here is the code:
>
> def add_change_listener(self, listener):
> '''
>
> Returns list of listeners just for testing.
> >>> def m
[Raymond Hettinger]
> ...
> The asymmetric handling of denormals by the atof() and ftoa() functions is
> why you see a difference. A consequence of that asymmetry is the breakdown
> of the expected eval(repr(f))==f invariant:
Just noting that such behavior is a violation of the 754 standard for
s
[kristi holsinger]
> please remove [EMAIL PROTECTED] from the mailing list! thank you
This is self-service. You need to go to
http://mail.python.org/mailman/listinfo/tutor
and unsubscribe youself (look for the "Unsubscribe or edit options"
button near the bottom of the page).
_
[Intercodes]
> This question is just out of curiosity. I am working with this dragon book.
> From what I have learnt so far, RE uses either NFA or DFA to check whether
> the string is accepted or not. (Correct?)
In the world of "computer science" regular expressions, yes. But the
things _called_
[Lance E Sloan]
> ...
> (I think it's a little too bad that the timedelta class represents all
> deltas as days and seconds.
And microseconds.
> That must be why they don't support months, since months have
> different lengths. IMHO...)
That's right. It's hard to argue about what days, seconds
[Liam Clarke]
> Erm, can someone please aid me? I'm using Windows XP, haven't tested
> this code on Linux yet, but, well watch this...
>
> '<' indicates little-endian, @ indicates native. i is an integer,
Yes x 3.
> q is a long.
No. q in native mode is C "long long" on Linux, or "_int64" on
Win
[Alan Gauld]
> Thanks Danny, interesting link in that it shows a solution I
> didn't know about in the one-liner at the bottom of the discussion.
>
> But really I was hoping someone could explain *why* there is a
> difference. If PATHEXT can detect that intest.py needs to be run
> through Python w
[Max Noel]
> ...
> This is where the palette comes into play. Each 256-color image
> has a palette, which is basically an array of length 256, where each
> element is a (24-bit RGB) color. The color data for each pixel in the
> image is actually an index in this array.
Adding a bit of detail,
[D. Hartley]
> Max - yep, and the hint was "BUSY" (... BZ...)...
>
> Unfortunately that hint doesnt lead me anywhere (except to bz2, which
> involves compression, and didnt seem very likely).
>
> I went through and removed all the \x## 's that represented
> 'unprintable'/carraigereturn/etc characte
[Jacob S.]
> Ok, I'm stuck on #4
>
> I tried using urllib like the source hints... but, when I run my automation
> of the process of typing in the new nothing, I run through about 15 pages,
> then I notice that they add an extra number in the text.
> 60167 or something like that
> This is encouragi
[Max Noel]
...
> In fact, I am (and will probably give up) at number 9. I was
> able to do #7 without using PIL, but it seems that it is once again
> necessary for #9, and I'm not gonna be able to use a workaround this
> time.
What do you have against PIL ?
Processing images has played no par
[Gooch, John]
> Thank you for the idea, I could have been more clear that days part of the
> date isn't important. Here is what I came up with:
>
>currentDate = datetime.datetime.fromtimestamp( time.time() )
Easier:
today = datetime.date.today()
>archMonth = 0
>archYear = 0
>
[Tony Meyer]
...
>> Somewhat ironically, one of the tenets of Python is "there should be one--
>> and preferably only one --obvious way to do it." (type "import this" at an
[Marilyn Davis]
> In this case, there is: regular expressions. :^)
>
> "Obvious" doesn't mean we can, necessarily, all see i
[Jacob S.]
>I'm having a problem that is ticking me off. (to put it lightly)
> Why does decimal do this -- I thought that getcontext().prec
> was number of decimal places?
It's unclear what you mean by "decimal places". From context, you
_appear_ to mean "number of decimal digits after the r
[Alan Gauld]
> OK, The timbot's word is good enough for me, I won't bother
> looking at the code, I'll revert to my previous assumption! :-)
It's educational to look at the code anyway . Here it is, from
Python's listobject.c:
static int
list_length(PyListObject *a)
{
return a->ob_size;
[Gonçalo Rodrigues]
> It this correct? Python lists are not linked-lists (as in Scheme, for
> example). They are more like arrays (or vectors in C++/Java) with a
> little more sofistication built into them to allow, for example, to
> amortize over time a sequence of append operations. But in a nuts
[Brian van den Broek]
> in Marc's check_range thread, I had proposed:
>
> def check_in_range(value):
>
> in_range = False
> if 9 < value < 90:
> in_range = True
> return in_range
>
> and DogWalker suggested the better:
>
> def check_in_range(value):
> return 9 < value < 90
[Ertl, John]
> I need to take a number and turn it into a formatted string.
> The final output needs to look like when the X is the
> integer part padded on the left and Y is the decimal part padded
> on the right.
> I figured I could split the number at "." and then use zfill or
> some
[Dick Moores]
>>> Actually, I'm trying to write a Python script that computes all 3
>>> roots of a cubic equation. Do you happen to have one tucked
>>> away in your store of wisdom and tricks? (One for real coefficients
>>> will do).
[Tim Peters]
>>
[Dick Moores]
> Aw, that's just amazing.
Well, complex numbers are amazing in many ways. The code is actually
obvious, if you understand the motivation. Polar coordinates are more
natural for complex * / and **. If you a view a complex number c as
a vector in the complex plane (from the origin
[Dick Moores]
> VERY helpful, Matt. Thanks.
>
> One question: This seems to not compute accurately at all
> when the imaginary part of number=complex() is other than 0.
That's just because the math was wrong . Starting with theta =
0.0 *assumed* the imaginary part is 0, although I can't guess wh
[Dick Moores]
...
> Brian, where did you learn about the ".seconds". And
> the .year, .month,.day of
>
> "alarm_datetime = datetime.datetime(now.year + 4, now.month,
> now.day, alarm_hour, alarm_minute)"?
>
> Does this come from a general knowledge of OOP, or is it
> somewhere in the Pytho
[Brian van den Broek]
...
> Or, so I thought. I'd first tried getting the alarm datetime by simply
> taking the date component of datetime.datetime.now() and adding
> to the day value. That works fine, provided you are not on the last
> day of the month. But, when checking boundary cases before
> p
[Dave S <[EMAIL PROTECTED]>]
> OK I may be pushing it, ;-)
Yup .
> I need a script to sleep from any point to 8:05AM when in needs to
> re-start.
>
> So I calculate the number of seconds with the following
>
> def secs_till_805():
># Returns the number of seconds till 8:05AM
>
>s
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