Re: some problems for an introductory python test

2021-08-11 Thread Wolfram Hinderer via Python-list
ider that surprising, but maybe I should? (Honest question, I really don't know.) -- Wolfram Hinderer -- https://mail.python.org/mailman/listinfo/python-list

Re: count consecutive elements

2021-01-14 Thread Wolfram Hinderer via Python-list
Am 13.01.2021 um 22:20 schrieb Bischoop: I want to to display a number or an alphabet which appears mostly consecutive in a given string or numbers or both Examples s= ' aabskaaabad' output: c # c appears 4 consecutive times 8bbakebaoa output: b #b appears 2 consecutive times You can

Re: best way to remove leading zeros from a tuple like string

2018-05-21 Thread Wolfram Hinderer via Python-list
Am 21.05.2018 um 01:16 schrieb bruceg113...@gmail.com: If I decide I need the parentheses, this works. "(" + ",".join([str(int(i)) for i in s[1:-1].split(",")]) + ")" '(128,20,8,255,-1203,1,0,-123)' Thanks, Bruce Creating the tuple seems to be even simpler. >>> str(tuple(map(int, s[1:-1].s

Re: N-grams

2016-11-09 Thread Wolfram Hinderer
Am 10.11.2016 um 03:06 schrieb Paul Rubin: This can probably be cleaned up some: from itertools import islice from collections import deque def ngram(n, seq): it = iter(seq) d = deque(islice(it, n)) if len(d) != n: return for s in

Re: find all multiplicands and multipliers for a number

2015-04-11 Thread wolfram . hinderer
Am Samstag, 11. April 2015 09:14:50 UTC+2 schrieb Marko Rauhamaa: > Paul Rubin : > > > This takes about 4 seconds on a Intel(R) Core(TM) i5-3230M CPU @ 2.60GHz > > laptop (64 bit linux): > > Converted to Python3: > > #!/usr/

Re: copy on write

2012-02-06 Thread Wolfram Hinderer
On 3 Feb., 11:47, John O'Hagan wrote: > But isn't it equally true if we say that z = t[1], then t[1] += x is > syntactic sugar for z = z.__iadd__(x)? Why should that fail, if z can handle > it? It's more like syntactic sugar for y = t; z = y.__getitem__(1); z.__iadd__(x); y.__setitem__(1, z)

Re: Faster Recursive Fibonacci Numbers

2011-05-17 Thread Wolfram Hinderer
On 17 Mai, 20:56, geremy condra wrote: > On Tue, May 17, 2011 at 10:19 AM, Jussi Piitulainen > > wrote: > > geremy condra writes: > > >> or O(1): > > >> ö = (1 + sqrt(5)) / 2 > >> def fib(n): > >>     numerator = (ö**n) - (1 - ö)**n > >>     denominator = sqrt(5) > >>     return round(numerator/d

Re: How on Factorial

2010-10-30 Thread Wolfram Hinderer
On 27 Okt., 10:27, Arnaud Delobelle wrote: > True.  It's far too verbose.  I'd go for something like: > >     f=lambda n:n<=0 or n*f(~-n) > > I've saved a few precious keystrokes and used the very handy ~- idiom! You can replace "n<=0" with "n<1". Then you can leave out the space before "or" ("0o

Re: default behavior

2010-08-06 Thread Wolfram Hinderer
On 6 Aug., 22:07, John Posner wrote: > On 8/2/2010 11:00 PM, John Posner wrote: > > > On 7/31/2010 1:31 PM, John Posner wrote: > > >> Caveat -- there's another description of defaultdict here: > > >>http://docs.python.org/library/collections.html#collections.defaultdict > > >> ... and it's bogus.

Re: Python -- floating point arithmetic

2010-07-08 Thread Wolfram Hinderer
On 8 Jul., 15:10, Ethan Furman wrote: > Interesting.  I knew when I posted my above comment that I was ignoring > such situations.  I cannot comment on the code itself as I am unaware of > the algorithm, and haven't studied numbers extensively (although I do > find them very interesting). > > So

Re: Python -- floating point arithmetic

2010-07-07 Thread Wolfram Hinderer
On 7 Jul., 19:32, Ethan Furman wrote: > Nobody wrote: > > On Wed, 07 Jul 2010 15:08:07 +0200, Thomas Jollans wrote: > > >> you should never rely on a floating-point number to have exactly a > >> certain value. > > > "Never" is an overstatement. There are situations where you can rely > > upon a fl

Re: Composition of functions

2010-07-01 Thread Wolfram Hinderer
On 1 Jul., 06:04, Stephen Hansen wrote: > The 'reversed' and 'sorted' functions are generators that lazilly > convert an iterable as needed. 'sorted' returns a new list (and is not lazy). -- http://mail.python.org/mailman/listinfo/python-list

Re: Fastest way to calculate leading whitespace

2010-05-09 Thread Wolfram Hinderer
On 8 Mai, 21:46, Steven D'Aprano wrote: > On Sat, 08 May 2010 12:15:22 -0700, Wolfram Hinderer wrote: > > Returning s[:-1 - len(t)] is faster. > > I'm sure it is. Unfortunately, it's also incorrect. > However, s[:-len(t)] should be both faster and correct. Ou

Re: Fastest way to calculate leading whitespace

2010-05-08 Thread Wolfram Hinderer
On 8 Mai, 20:46, Steven D'Aprano wrote: > def get_leading_whitespace(s): >     t = s.lstrip() >     return s[:len(s)-len(t)] > > >>> c = get_leading_whitespace(a) > >>> assert c == leading_whitespace > > Unless your strings are very large, this is likely to be faster than any > other pure-Python

Re: Traversing through variable-sized lists

2010-02-17 Thread Wolfram Hinderer
On 17 Feb., 19:10, Andrej Mitrovic wrote: > Hi, > > I couldn't figure out a better description for the Subject line, but > anyway, I have the following: > > _num_frames = 32 > _frames = range(0, _num_frames) # This is a list of actual objects, > I'm just pseudocoding here. > _values = [0, 1, 2, 3,

Re: Performance of lists vs. list comprehensions

2010-01-19 Thread Wolfram Hinderer
On 19 Jan., 21:06, Gerald Britton wrote: > [snip] > > > > > Yes, list building from a generator expression *is* expensive. And > > join has to do it, because it has to iterate twice over the iterable > > passed in: once for calculating the memory needed for the joined > > string, and once more to

Re: Performance of lists vs. list comprehensions

2010-01-19 Thread Wolfram Hinderer
On 19 Jan., 16:30, Gerald Britton wrote: > >>> Timer("' '.join([x for x in l])", 'l = map(str,range(10))').timeit() > > 2.9967339038848877 > > >>> Timer("' '.join(x for x in l)", 'l = map(str,range(10))').timeit() > > 7.2045478820800781 [...] > 2. Why should the "pure" list comprehension be slow

Re: Writing a string.ishex function

2010-01-14 Thread Wolfram Hinderer
On 14 Jan., 19:48, MRAB wrote: > Arnaud Delobelle wrote: > > "D'Arcy J.M. Cain" writes: > > >> On Thu, 14 Jan 2010 09:07:47 -0800 > >> Chris Rebert wrote: > >>> Even more succinctly: > > >>> def ishex(s): > >>>     return all(c in string.hexdigits for c in s) > >> I'll see your two-liner and rai

Re: Dangerous behavior of list(generator)

2010-01-01 Thread Wolfram Hinderer
On 1 Jan., 02:47, Steven D'Aprano wrote: > On Thu, 31 Dec 2009 11:34:39 -0800, Tom Machinski wrote: > > On Wed, Dec 30, 2009 at 4:01 PM, Steven D'Aprano > > wrote: > >> On Wed, 30 Dec 2009 15:18:11 -0800, Tom Machinski wrote: > >>> Bottom line, I'm going to have to remove this pattern from my c

Re: unpacking vars from list of tuples

2009-09-15 Thread Wolfram Hinderer
On 15 Sep., 23:51, Ross wrote: > If I have a list of tuples: > >    k=[("a", "bob", "c"), ("p", "joe", "d"), ("x", "mary", "z")] > > and I want to pull the middle element out of each tuple to make a new > list: > > myList = ["bob", "joe", "mary"] if a tuple is OK: zip(*k)[1] -- http://mail.pyth

Re: Turtle Graphics are incompatible with gmpy

2009-08-05 Thread Wolfram Hinderer
On 5 Aug., 21:31, Mensanator wrote: > > >>> import turtle > >>> tooter = turtle.Turtle() > >>> tooter.tracer > > Traceback (most recent call last): >   File "", line 1, in >     tooter.tracer > AttributeError: 'Turtle' object has no attribute 'tracer'>>> > tooter.hideturtle() > >>> tooter.speed(

Re: Self function

2009-05-05 Thread wolfram . hinderer
On 5 Mai, 08:08, Steven D'Aprano wrote: > Self-reflective functions like these are (almost?) unique in Python in > that they require a known name to work correctly. You can rename a class, > instance or module and expect it to continue to work, but not so for such > functions. When editing source

Re: Functional schmunctional...

2009-02-11 Thread wolfram . hinderer
On 10 Feb., 21:28, r0g wrote: > def inet2ip(n, l=[], c=4): >   if c==0: return ".".join(l) >   p = 256**( c-1 ) >   l.append( str(n/p) ) >   return inet2ip( n-(n/p)*p, l, c-1 ) > The results for 1 > iterations of each were as follows... > > 0.113744974136 seconds for old INET->IP method > 27

Re: seemingly simple list indexing problem

2008-07-30 Thread wolfram . hinderer
On 29 Jul., 01:05, Raymond Hettinger <[EMAIL PROTECTED]> wrote: > [Ervan Ensis] > > > I have a list like [108, 58, 68]. I want to return > > the sorted indices of these items in the same order > > as the original list. So I should return [2, 0, 1] > > One solution is to think of the list indexes

Re: Can this program be shortened? Measuring program-length?

2008-07-10 Thread wolfram . hinderer
On 10 Jul., 21:57, "r.e.s." <[EMAIL PROTECTED]> wrote: > Can the following program be shortened? ... > > def h(n,m): > E=n, > while (E!=())*m>0:n=h(n+1,m-1);E=E[:-1]+(E[-1]>0)*(E[-1]-1,)*n > return n > h(9,9) > Some ideas... # h is your version def h(n,m): E=n, while (E!=())*m>0:n=h(n+1,m-1)

Re: Indentation and optional delimiters

2008-02-26 Thread wolfram . hinderer
On 26 Feb., 14:36, [EMAIL PROTECTED] wrote: > A possible solution to this problem is "optional delimiters". What's > the path of less resistance to implement such "optional delimiters"? > Is to use comments. For example: #} or #: or something similar. > If you use such pairs of symbols in a systema

Re: Just for fun: Countdown numbers game solver

2008-02-17 Thread wolfram . hinderer
On 22 Jan., 23:56, [EMAIL PROTECTED] wrote: > So anyone got an answer to which set of numbers gives the most targets > from 100 onwards say (or from 0 onwards)? IsPythonupto the task? It's (5, 8, 9, 50, 75, 100): 47561 targets altogether (including negative ones), 25814 targets >= 100. (BTW, 1226