Re: Trying to understand nested loops

On 08/08/2022 12:59, Dan Purgert wrote: dn wrote: On 06/08/2022 11.41, avi.e.gr...@gmail.com wrote: I wonder if someone is pulling our leg as they are sending from an invalid email address of "GB " which is a bit sick. There are a number of folk who use evidently false email addresses - the

Re: Trying to understand nested loops

-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 dn wrote: > On 06/08/2022 11.41, avi.e.gr...@gmail.com wrote: >> I wonder if someone is pulling our leg as they are sending from an >> invalid email address of "GB " which is >> a bit sick. > > There are a number of folk who use evidently false email

RE: Trying to understand nested loops

Behalf Of Chris Angelico Sent: Saturday, August 6, 2022 8:12 AM To: python-list@python.org Subject: Re: Trying to understand nested loops On Sat, 6 Aug 2022 at 22:08, Richard Damon wrote: > > On 8/6/22 12:01 AM, Chris Angelico wrote: > > On Sat, 6 Aug 2022 at 13:54, Dan Stromberg wrote:

Re: Trying to understand nested loops

On Sat, 6 Aug 2022 at 22:39, Richard Damon wrote: > > On 8/6/22 8:12 AM, Chris Angelico wrote: > > On Sat, 6 Aug 2022 at 22:08, Richard Damon wrote: > >> On 8/6/22 12:01 AM, Chris Angelico wrote: > >>> On Sat, 6 Aug 2022 at 13:54, Dan Stromberg wrote: > On Fri, Aug 5, 2022 at 12:54 PM Grant

Re: Trying to understand nested loops

On 8/6/22 8:12 AM, Chris Angelico wrote: On Sat, 6 Aug 2022 at 22:08, Richard Damon wrote: On 8/6/22 12:01 AM, Chris Angelico wrote: On Sat, 6 Aug 2022 at 13:54, Dan Stromberg wrote: On Fri, Aug 5, 2022 at 12:54 PM Grant Edwards wrote: In C, this doesn't do what it looks like it's suppose

Re: Trying to understand nested loops

On Sat, 6 Aug 2022 at 22:08, Richard Damon wrote: > > On 8/6/22 12:01 AM, Chris Angelico wrote: > > On Sat, 6 Aug 2022 at 13:54, Dan Stromberg wrote: > >> On Fri, Aug 5, 2022 at 12:54 PM Grant Edwards > >> wrote: > >> > >>> In C, this doesn't do what it looks like it's supposed to do. > >>> > >>

Re: Trying to understand nested loops

On 8/6/22 12:01 AM, Chris Angelico wrote: On Sat, 6 Aug 2022 at 13:54, Dan Stromberg wrote: On Fri, Aug 5, 2022 at 12:54 PM Grant Edwards wrote: In C, this doesn't do what it looks like it's supposed to do. if (foo) do_this(); and_this(); then_do_this(); It's been quit

Re: Trying to understand nested loops

On Sat, 6 Aug 2022 at 13:54, Dan Stromberg wrote: > > On Fri, Aug 5, 2022 at 12:54 PM Grant Edwards > wrote: > > > In C, this doesn't do what it looks like it's supposed to do. > > > >if (foo) > > do_this(); > > and_this(); > >then_do_this(); > > > It's been quite a while since

Re: Trying to understand nested loops

On Fri, Aug 5, 2022 at 12:54 PM Grant Edwards wrote: > In C, this doesn't do what it looks like it's supposed to do. > >if (foo) > do_this(); > and_this(); >then_do_this(); > It's been quite a while since I used C, but with the right compiler flag(s), I think this may be a thing

Re: Trying to understand nested loops

On Fri, 5 Aug 2022 08:34:45 +0100, ojomooluwatolami675 wrote: > Hello, I’m new to learning python and I stumbled upon a question nested > loops. This is the question below. Can you please how they arrived at 9 > as the answer. Thanks > > var = 0 for i in range(3): > for j

RE: Trying to understand nested loops

write articles or books and wants to see what people think but then does not participate or tell us that is what they wanted. My point was not to tell anyone else here what to do, simply that I will be cautious with such posters as I have way better things to do! Nested loops are indeed a hard

Re: Trying to understand nested loops

On 06/08/2022 11.41, avi.e.gr...@gmail.com wrote: > I wonder if someone is pulling our leg as they are sending from an invalid > email address of "GB " which is a bit sick. There are a number of folk who use evidently false email addresses - the OP's had me amused. Such 'hiding' is a matter for t

Re: Trying to understand nested loops

On Fri, Aug 5, 2022 at 12:30 PM GB wrote: > On 05/08/2022 08:56, Frank Millman wrote: > > > BTW, there is an indentation error in your original post - line 5 should > > line up with line 4. > > As a Python beginner, I find that Python is annoyingly picky about > indents. And, the significance of

RE: Trying to understand nested loops

r at least that they have spent any serious time learning. -Original Message- From: Python-list On Behalf Of GB Sent: Friday, August 5, 2022 5:57 AM To: python-list@python.org Subject: Re: Trying to understand nested loops On 05/08/2022 08:56, Frank Millman wrote: > BTW, there is an inde

Re: Trying to understand nested loops

On 06/08/2022 10.50, Dan Stromberg wrote: > On Fri, Aug 5, 2022 at 12:35 AM wrote: ... > Of if you don't have (or want) a debugger, you could change it to: > > var = 0 > for i in range(3): > print('i is', i) > for j in range(-2,-7,-2): > print('j is', j) > var += 1 > print(var) >

Re: Trying to understand nested loops

On Fri, Aug 5, 2022 at 12:35 AM wrote: > Hello, I’m new to learning python and I stumbled upon a question nested > loops. This is the question below. Can you please how they arrived at 9 as > the answer. Thanks > > var = 0 > for i in range(3): > for j in range(-2,-

Re: Trying to understand nested loops

On 8/5/22 03:56, GB wrote: > On 05/08/2022 08:56, Frank Millman wrote: > >> BTW, there is an indentation error in your original post - line 5 >> should line up with line 4. > > As a Python beginner, I find that Python is annoyingly picky about > indents.  And, the significance of indents is a bi

Re: Trying to understand nested loops

On 2022-08-05, GB wrote: >> BTW, there is an indentation error in your original post - line 5 >> should line up with line 4. > > As a Python beginner, I find that Python is annoyingly picky about > indents. And, the significance of indents is a bit of a minefield for > beginners. As a C begin

Re: Trying to understand nested loops

On 05/08/2022 08:56, Frank Millman wrote: BTW, there is an indentation error in your original post - line 5 should line up with line 4. As a Python beginner, I find that Python is annoyingly picky about indents. And, the significance of indents is a bit of a minefield for beginners. For

Re: Trying to understand nested loops

ojomooluwatolami...@gmail.com wrote at 2022-8-5 08:34 +0100: >Hello, I’m new to learning python and I stumbled upon a question nested loops. For future, more complex, questions of this kind, you might have a look at the module `pdb` in Python's runtime library. It implements a debugg

Re: Trying to understand nested loops

It’s also a poor code example. Doing a pointless double loop is not good instructional practice, especially when simpler alternatives exist. e.g. for i in range(3): for j in range(-2.-7,-2): print(i +j ) — Gerard Weatherby | Application Architect NMRbox | NAN | Department of Molecular Biol

Re: Trying to understand nested loops

On 05Aug2022 09:47, Lars Liedtke wrote: >this looks to me like it might be a piece of homework, as it would be >given by teachers or professors. > >This list has got the rule, that members do not solve other's >homework. Because very often homework is meant to sit down and think >about it. Ver

Re: Trying to understand nested loops

On 2022-08-05 9:34 AM, ojomooluwatolami...@gmail.com wrote: Hello, I’m new to learning python and I stumbled upon a question nested loops. This is the question below. Can you please how they arrived at 9 as the answer. Thanks var = 0 for i in range(3): for j in range(-2,-7,-2): var

Re: Trying to understand nested loops

um 09:34 schrieb ojomooluwatolami...@gmail.com: Hello, I’m new to learning python and I stumbled upon a question nested loops. This is the question below. Can you please how they arrived at 9 as the answer. Thanks var = 0 for i in range(3): for j in range(-2,-7,-2): var += 1 prin

Trying to understand nested loops

Hello, I’m new to learning python and I stumbled upon a question nested loops. This is the question below. Can you please how they arrived at 9 as the answer. Thanks var = 0 for i in range(3): for j in range(-2,-7,-2): var += 1 print(var) Sent from my iPhone -- https

Re: clever exit of nested loops

Neal Becker wrote: but it does violate the principle "Exceptions should be used for exceptional conditions). Python doesn't really go in for that philosophy. Exceptions are often used for flow control, e.g. StopIteration. -- Greg -- https://mail.python.org/mailman/listinfo/python-list

Re: clever exit of nested loops

On 2018-09-26 21:06, Mark Lawrence wrote: > > To me the Ned Batchelder presentation > https://www.youtube.com/watch?v=EnSu9hHGq5o "Loop like a Native" is the > definitive way on how to deal with loops in Python. > Hear, hear. Great talk. -- https://mail.python.org/mailman/listinfo/python-list

Re: clever exit of nested loops

Christian Gollwitzer wrote: > Am 26.09.18 um 12:28 schrieb Bart: >> On 26/09/2018 10:10, Peter Otten wrote: >>> class Break(Exception): >>> pass >>> >>> try: >>> for i in range(10): >>> print(f'i: {i}') >>> for j in range(10): >>> print(f'\tj: {j}') >>> for k in range(10): >>> print(f'\t\tk: {k}')

Re: clever exit of nested loops

Am 26.09.18 um 12:28 schrieb Bart: On 26/09/2018 10:10, Peter Otten wrote: class Break(Exception): pass try: for i in range(10): print(f'i: {i}') for j in range(10): print(f'\tj: {j}') for k in range(10):   

Re: clever exit of nested loops

On Wednesday, September 26, 2018 at 12:50:20 AM UTC-7, vito.d...@gmail.com wrote: > I have "abused" the "else" clause of the loops to makes a break "broke" more > loops I did this once upon a time. In recent years, when I start writing tricky nested loop

Re: clever exit of nested loops

On 26/09/18 08:50, vito.detul...@gmail.com wrote: Hi Today I've added a couple of lines in my source code, and I'm very ashamed of it. it "runs", and I know what it does (for now), but it's "too clever". I have "abused" the "else" clause of the loops to makes a break "broke" more loops f

Re: clever exit of nested loops

vito.detul...@gmail.com wrote: > Hi > Today I've added a couple of lines in my source code, and I'm very ashamed > of it. it "runs", and I know what it does (for now), but it's "too > clever". I have "abused" the "else" clause of the loops to makes a break > "broke" more loops > > > for i in

Re: clever exit of nested loops

On Wed, Sep 26, 2018 at 5:56 PM wrote: > > Hi > Today I've added a couple of lines in my source code, and I'm very ashamed of > it. > it "runs", and I know what it does (for now), but it's "too clever". > I have "abused" the "else" clause of the loops to makes a break "broke" more > loops > > >

clever exit of nested loops

Hi Today I've added a couple of lines in my source code, and I'm very ashamed of it. it "runs", and I know what it does (for now), but it's "too clever". I have "abused" the "else" clause of the loops to makes a break "broke" more loops for i in range(10): print(f'i: {i}') f

Re: nested loops in Python

I think you are right, it's the assignment itself which is slow. Merged loop is only a tad quicker. On Thursday, September 8, 2016 at 6:04:41 PM UTC+1, Christian Gollwitzer wrote: > > Why nested loops are so slow in Python? Is it because new contexts are > > created? > >

Re: nested loops in Python

Am 08.09.16 um 12:20 schrieb Igor Kozin: Why nested loops are so slow in Python? Is it because new contexts are created? For more details, see http://stackoverflow.com/questions/26611043/numpy-vs-cython-nested-loop-so-slow http://stackoverflow.com/questions/39371021/efficient-loop-over-numpy

Re: nested loops in Python

On Thu, Sep 8, 2016 at 8:20 PM, Igor Kozin wrote: > Why nested loops are so slow in Python? Is it because new contexts are > created? > For more details, see > http://stackoverflow.com/questions/26611043/numpy-vs-cython-nested-loop-so-slow > http://stackoverflow.com/questions/393

nested loops in Python

Why nested loops are so slow in Python? Is it because new contexts are created? For more details, see http://stackoverflow.com/questions/26611043/numpy-vs-cython-nested-loop-so-slow http://stackoverflow.com/questions/39371021/efficient-loop-over-numpy-array Thanks! -- https://mail.python.org

Re: Nested loops is strangely slow, totally at a loss.

On Wed, Dec 10, 2014 at 9:01 AM, Ian Kelly wrote: > This also seems perfectly natural: > > def len(iterable): > return sum(1 for item in iterable) > > My observation is that seems strange to me that one standard sequence operation should be supported for arbitrary iterators and the other not.

Re: Nested loops is strangely slow, totally at a loss.

On Wed, Dec 10, 2014 at 1:21 AM, Peter Otten <__pete...@web.de> wrote: > > Ian Kelly wrote: > > Huh, I wasn't even aware that membership tests worked on iterables with no > > __contains__ method. Seems odd to me that 'x in y' should be supported but > > not 'len(y)'. > > To me > > def contains(iter

Re: Nested loops is strangely slow, totally at a loss.

Shiyao Ma wrote: > Thanks guys. > > I was only aware of a limited iterables which themselves are iterators, > e.g., the generator. > > Seems like its really a pitfall. Any glossary, list on the iterables that > *might* exhaust themselves? Iterables include: - iterators - sequences (e.g. lists,

Re: Nested loops is strangely slow, totally at a loss.

Shiyao Ma wrote: > Thanks guys. > > I was only aware of a limited iterables which themselves are iterators, > e.g., the generator. > > Seems like its really a pitfall. Any glossary, list on the iterables that > *might* exhaust themselves? Usually the test iterable is iter(iterable) returns Tr

Re: Nested loops is strangely slow, totally at a loss.

Thanks guys. I was only aware of a limited iterables which themselves are iterators, e.g., the generator. Seems like its really a pitfall. Any glossary, list on the iterables that *might* exhaust themselves? Regards. -- https://mail.python.org/mailman/listinfo/python-list

Re: Nested loops is strangely slow, totally at a loss.

Ian Kelly wrote: > On Tue, Dec 9, 2014 at 11:30 PM, Chris Angelico wrote: >> Are you sure it isn't? Your 'space' is an iterable cubic >> cross-product. Your first loop checks (0,0,0) which is the first >> element returned, and is thus fast... but it also *consumes* that >> first element. The next

Re: Nested loops is strangely slow, totally at a loss.

On Wed, 10 Dec 2014 17:53:05 +1100, Chris Angelico wrote: > On Wed, Dec 10, 2014 at 5:44 PM, Steven D'Aprano > wrote: >> It would be nice if product iterators behaved like xrange() objects and >> could perform "in" tests without exhausting the iterator, but they >> don't. That's sad. > > It'd be

Re: Nested loops is strangely slow, totally at a loss.

On 12/10/2014 1:53 AM, Chris Angelico wrote: On Wed, Dec 10, 2014 at 5:44 PM, Steven D'Aprano wrote: It would be nice if product iterators behaved like xrange() objects and could perform "in" tests without exhausting the iterator, but they don't. That's sad. It'd be very difficult to do that

Re: Nested loops is strangely slow, totally at a loss.

On Tue, Dec 9, 2014 at 11:30 PM, Chris Angelico wrote: > Are you sure it isn't? Your 'space' is an iterable cubic > cross-product. Your first loop checks (0,0,0) which is the first > element returned, and is thus fast... but it also *consumes* that > first element. The next time you test it, the e

Re: Nested loops is strangely slow, totally at a loss.

On Wed, Dec 10, 2014 at 5:44 PM, Steven D'Aprano wrote: > It would be nice if product iterators behaved like xrange() objects and > could perform "in" tests without exhausting the iterator, but they don't. > That's sad. It'd be very difficult to do that in the general sense. But it should be poss

Re: Nested loops is strangely slow, totally at a loss.

On Wed, 10 Dec 2014 13:20:25 +0800, Shiyao Ma wrote: > When doing nested loop, the very first iteration of the innermost loop > ends ultimately slow. > > Let's the code speak. > > The following code is quite contrived. Actually it's derived from my > 3d-dct script. The actual difference is way m

Re: Nested loops is strangely slow, totally at a loss.

On Wed, Dec 10, 2014 at 4:20 PM, Shiyao Ma wrote: > from itertools import product > space_len = 580 > space = product(xrange(space_len), xrange(space_len), xrange(space_len)) > > sparse_cloud = product(xrange(1000), xrange(1000), xrange(1000)) > for i, j, k in sparse_cloud: > ts = timeit.defau

Re: Nested loops is strangely slow, totally at a loss.

One thing to note, the logic of using "in" is not of concern here. This is a *contrived* example, the problem is the slowness of the first iteration. -- https://mail.python.org/mailman/listinfo/python-list

Nested loops is strangely slow, totally at a loss.

When doing nested loop, the very first iteration of the innermost loop ends ultimately slow. Let's the code speak. The following code is quite contrived. Actually it's derived from my 3d-dct script. The actual difference is way more significant than this example. In case of any evil of gmail,

Re: nested loops

Hi! > leonardo writes: how can i have it print a row of stars beside each number, like this?: how many seconds?: 5 5 * * * * * 4 * * * * 3 * * * 2 * * 1 * blast off! --- snip --- sec = int(input("How many seconds? ")) for i in range(0,sec): print str(sec-i)+":"+" *"*(sec-i) print

Re: nested loops

leonardo writes: > how can i have it print a row of stars beside each number, like this?: > > how many seconds?: 5 > 5 * * * * * > 4 * * * * > 3 * * * > 2 * * > 1 * > blast off! You could use the repetition operator * since you have the number of repetitions needed in i. Alternatively, consider

Re: nested loops

On Mon, 25 Feb 2013 23:46:11 +0100, leonardo wrote: > hi everyone, > > i have the following program: > > import time count_timer = int(raw_input('how many seconds?: ')) > for i in range(count_timer, 0, -1): > print i time.sleep(1) > print 'blast off!' > > > this is the result: > > how ma

Re: nested loops

thanks for the help, it works Il 26/02/2013 10.58, Sven ha scritto: Here's one solution import time count_timer = int(raw_input('how many seconds?: ')) for i in range(count_timer, 0, -1): ||print i, print "*" * i time.sleep(1) print 'blast off!' On 25 February 2013 22:46, leonardo

Re: nested loops

Here's one solution import time count_timer = int(raw_input('how many seconds?: ')) for i in range(count_timer, 0, -1): print i, print "*" * i time.sleep(1) print 'blast off!' On 25 February 2013 22:46, leonardo wrote: > hi everyone, > > i have the following program: > > import tim

nested loops

hi everyone, i have the following program: import time count_timer = int(raw_input('how many seconds?: ')) for i in range(count_timer, 0, -1): print i time.sleep(1) print 'blast off!' this is the result: how many seconds?: 5 5 4 3 2 1 blast off! how can i have it print a row of star

Re: writing to a file from within nested loops

On 15/02/2012 20:12, Rituparna Sengupta wrote: Hi, I'm working on this code and I keep getting an error. It might be some very basic thing but I was wondering if someone could help. Its a loop within a loop. The part outside the innermost loop gets printed fine, but the part within the innerm

Re: writing to a file from within nested loops

On 02/15/2012 03:12 PM, Rituparna Sengupta wrote: Hi, I'm working on this code and I keep getting an error. It might be some very basic thing but I was wondering if someone could help. Its a loop within a loop. The part outside the innermost loop gets printed fine, but the part within the inn

Re: writing to a file from within nested loops

On Wed, Feb 15, 2012 at 12:12 PM, Rituparna Sengupta wrote: > Hi, > > I'm working on this code and I keep getting an error. It might be some very > basic thing but I was wondering if someone could help. Its a loop within a > loop. The part outside the innermost loop gets printed fine, but the pa

Re: writing to a file from within nested loops

On Wed, Feb 15, 2012 at 1:12 PM, Rituparna Sengupta wrote: > Hi, > > I'm working on this code and I keep getting an error. It might be some very > basic thing but I was wondering if someone could help. Its a loop within a > loop. The part outside the innermost loop gets printed fine, but the par

writing to a file from within nested loops

Hi, I'm working on this code and I keep getting an error. It might be some very basic thing but I was wondering if someone could help. Its a loop within a loop. The part outside the innermost loop gets printed fine, but the part within the innermost loop doesn't get printed. I get an error: 'st

Re: fun with nested loops

rejected the idea of named labels. I'd need to sit down and trace a few loops by hand to grasp it. I wonder how new people coming into the project find it? Personally, I consider two nested loops right on the boundary of my "magic number seven, plus or minus two" short term memory[1]

Re: fun with nested loops

I thought a bit about Carl's and Thomas' proposals, and it gave me an idea how this problem could be approached: Break is relatively easy to implement with a context manager that returns an iterable that throws an exception specific to that context manager: with named_loop(i for i in range(10)) as

Re: fun with nested loops

# loop 4b > for substeps in step2: > # at this point, we may have to > -leave loop 1 > -restart loop 2 > -restart loop 4b > ... > ...many more loops... > > > I don't see any

Re: fun with nested loops

On 9/1/2011 10:05 AM, Daniel wrote: You seems to be requesting one of the options in http://python.org/dev/peps/pep-3136/ Labeled break and continue (The 'Other languages' section omits Fortran.) The rejection post is at http://mail.python.org/pipermail/python-3000/2007-July/008663.html I basica

Re: fun with nested loops

Am 01.09.2011 16:05 schrieb Daniel: In pseudocode it looks like this, I am using @ to give loops a name: @loop1 for c in configurations: @loop2 while not_done: @loop3 while step1_did_not_work: @loop4 for substeps in step1 # loop 4a

Re: fun with nested loops

like semiconductor chips. The specification of these tests is already very complex, it has the form of the nested loops, for all these configurations try these steps, if they fail try them again n times, if it still doesn't work give up this configuration, if it works continue on to the

Re: fun with nested loops

Chris Angelico wrote: > Ah well, was worth a try. Raising exceptions smells wrong for this, > but peppering your code with sentinel checks isn't much better. I > don't really know what would be a good solution to this... except > maybe this, which was proposed a few years ago and which I'd never >

Re: fun with nested loops

are needed to be. Same applies to your data acquisition application. Unless you expect these non-CS people to be hacking the source code, they only interact with the interface, not the internals. Earlier, back in your initial post, you said: "I don't see any way to reduce these nested loop

Re: fun with nested loops

On Thu, Sep 1, 2011 at 5:07 AM, Daniel wrote: >> Do you only ever have one top-level loop that you would be naming? If > no, unfortunately not. The rough structure is several loops deep, and > I need to break/continue/restart many of them. > Continue is used more than break, because most of the ti

Re: fun with nested loops

> Do you only ever have one top-level loop that you would be naming? If no, unfortunately not. The rough structure is several loops deep, and I need to break/continue/restart many of them. Continue is used more than break, because most of the time that I find some strange value, I'd just _continue

Re: fun with nested loops

I am really hitting a wall at the moment. Maybe I am really missing an obvious solution, because breaking out of nested loops really doesn't seem like anything fancy. Fortran/c/c++/ Ruby/Perl all have that facility, even Java has named loops. -- http://mail.python.org/mailman/listinfo/python-list

Re: fun with nested loops

On Thu, Sep 1, 2011 at 1:51 AM, Daniel wrote: > > Has anyone an idea on a nice way to write breaks/continues/redos for > deeply > nested loops? > Do you only ever have one top-level loop that you would be naming? If so, put that loop into a function and use return instead of break

Re: fun with nested loops

in step2: >                 # at this point, we may have to >                 -leave loop 1 >                 -restart loop 2 >                 -restart loop 4b >                 ... >         ...many more loops... > > I don't see any way to reduce these nested loops lo

fun with nested loops

loop 2 -restart loop 4b ... ...many more loops... I don't see any way to reduce these nested loops logically, they describe pretty well what the software has to do. This is a data acquisition application, so on ever line there is a lot of IO that might

Re: flow control and nested loops

Raymond Hettinger: > Another approach for exiting multiple levels of loops is wrap the > inner calls in a function and return from them when needed: > >    def f(x): >        for y in y: >            for z in Z: >                if test1(x,y,z): >                    return >                frobnic

Re: flow control and nested loops

On Sep 25, 12:01 pm, kj wrote: > In Perl, one can label loops for finer flow control.  For example: > > X: for my $x (@X) { >   Y: for my $y (@Y) { >     for my $z (@Z) { >       next X if test1($x, $y, $z); >       next Y if test2($x, $y, $z); >       frobnicate($x, $y, $z); >     } >     glortz(

Re: flow control and nested loops

kj wrote: In Perl, one can label loops for finer flow control. For example: X: for my $x (@X) { Y: for my $y (@Y) { for my $z (@Z) { next X if test1($x, $y, $z); next Y if test2($x, $y, $z); frobnicate($x, $y, $z); } glortz($x, $y); } splat($x); } What's

Re: flow control and nested loops

r code so you didn't have to do that. Seriously though, I find both the perl and python versions non-obvious. You have had to use constructs like this in practice? Generally, I would use "flags" in tricky nested loops just like you did, perhaps with some comments to clarify things.

flow control and nested loops

In Perl, one can label loops for finer flow control. For example: X: for my $x (@X) { Y: for my $y (@Y) { for my $z (@Z) { next X if test1($x, $y, $z); next Y if test2($x, $y, $z); frobnicate($x, $y, $z); } glortz($x, $y); } splat($x); } What's considered

Re: Coding Nested Loops

On Sat, 16 Sep 2006, Dan Sommers wrote: > No, they all work the same way (thank goodness!). The "." between "wx" > and "frame" is the same dot as is between "random" and "choice" (i.e., > random.choice is the same construct as wx.frame). Ah, yes. I totally forgot this. Thanks for the reminde

Re: Coding Nested Loops

On Sat, 16 Sep 2006 10:06:25 -0700 (PDT), Rich Shepard <[EMAIL PROTECTED]> wrote: > On Sat, 16 Sep 2006, Dan Sommers wrote: >> When you import random, all you're doing is importing the module; you >> have to specify any given attribute thereof: > I thought that was implied. For example, I use

Re: Coding Nested Loops

On Sat, 16 Sep 2006, Dan Sommers wrote: > When you import random, all you're doing is importing the module; you have > to specify any given attribute thereof: Dan, I thought that was implied. For example, I use 'import wx' and can then instantiate wx.frame, wx.dialogbox, etc. without explicit

Re: Coding Nested Loops

On Sat, 16 Sep 2006 08:29:26 -0700 (PDT), Rich Shepard <[EMAIL PROTECTED]> wrote: > Two questions germane to random: 1) Why wasn't choice available when > I used 'import random,' ... When you import random, all you're doing is importing the module; you have to specify any given attribute thereo

Re: Coding Nested Loops

rnal's annual obfuscated C contests. :-) > from random import choice Two questions germane to random: 1) Why wasn't choice available when I used 'import random,' and 2) What are the differences between 'choice' and 'shuffle?' > Of course nested lo

Re: Coding Nested Loops

range(180), [x]*60 + [y]*60 + [z]*60, ([a]*13 + [b]*14 + [c]*33) * 3] + [random_floats(third)]*28 for row in izip(*columns): print row Of course nested loops will work, too. Use whatever you find easiest to maintain. Peter -- http://mail.python.org/mailman/listinfo/python-list

Re: Coding Nested Loops

On Fri, 15 Sep 2006, Peter Otten wrote: > It's not clear to me why you would use dictionaries, especially as they > are unordered; I used lists instead: ... > Now that is a nice occasion to get acquainted with the itertools module... Peter, I have to study the docs to understand what's g

Re: Coding Nested Loops

Peter Otten wrote: > from itertools import count, izip, cycle, chain, repeat, starmap, imap > from random import choice > > first = ["X", "Y", "Z"] > second = ["A", "B", "C"] > second_count = [13, 14, 33] > third = [1.1, 2.2, 3.3, 4.4] > > random_floats = imap(choice, repeat(third)) > columns = [

Re: Coding Nested Loops

On Fri, 15 Sep 2006, Bjoern Schliessmann wrote: That doesn't answer the question. A list of 2-tuples would do the same (and was ordered and could be indexed). Björn, et al.: For the purpose of generating a data sample, the list of 2-tuples will work. Thanks all, Rich -- Richard B. Shepar

Re: Coding Nested Loops

Rich Shepard wrote: > On Fri, 15 Sep 2006, Peter Otten wrote: >> It's not clear to me why you would use dictionaries, especially >> as they are unordered; I used lists instead: >Because the data comes via a serial port as sequences of two >bytes from an > OMR reader, and the byte pairs n

Re: Coding Nested Loops

On Fri, 15 Sep 2006, Peter Otten wrote: > It's not clear to me why you would use dictionaries, especially as they > are unordered; I used lists instead: Peter, Because the data comes via a serial port as sequences of two bytes from an OMR reader, and the byte pairs need to be converted into v

Re: Coding Nested Loops

Rich Shepard wrote: >I want to code what would be nested "for" loops in C, but I don't know >the > most elegant way of doing the same thing in python. So I need to learn how > from you folks. Here's what I need to do: build a database table of 180 > rows. Each row contains 31 columns: the

Coding Nested Loops

I want to code what would be nested "for" loops in C, but I don't know the most elegant way of doing the same thing in python. So I need to learn how from you folks. Here's what I need to do: build a database table of 180 rows. Each row contains 31 columns: the first is an automatically incremen

Re: Nested loops confusion

[EMAIL PROTECTED] wrote: > Call me crazy, but be careful when programming python in different text > editors and in general, ie cutting and pasting, tabing and spacing. > Loops can look fine and not work (try moving around test print > statements for iterators), in this case try re-tabing your inde

Re: Nested loops confusion

>I'm still not sure what was stopping the inner >loop from working earlier - but removing the redundancy in "j=0" and so >on seems to have solved it. Call me crazy, but be careful when programming python in different text editors and in general, ie cutting and pasting, tabing and spacing. Loops ca

Re: Nested loops confusion

On 11/05/2006 5:59 PM, Matthew Graham wrote: > Thanks very much for the advice, have tidied it up and tested and seems > to be working as needed. Seems to be working? Consider where you have the expression x^2 + y^2 ... I'd like to bet that you mean "x squared" etc, not "x exclusive-or 2" etc.

Re: Nested loops confusion

Thanks very much for the advice, have tidied it up and tested and seems to be working as needed. I'm still not sure what was stopping the inner loop from working earlier - but removing the redundancy in "j=0" and so on seems to have solved it. Matt Dennis Lee Bieber wrote: > If that wor

Re: Nested loops confusion

Oops, I forget to reset the j after the inner loop. Always manage to work these things out just after asking for help! ;-) Matthew Graham wrote: > Hi, > > I expect this is very obvious for anyone who knows what they're doing - > but I don't understand what's the problem with the following code

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