Re: Request for help
On 2016-07-19 22:21, alister wrote: On Tue, 19 Jul 2016 13:06:39 +1000, Steven D'Aprano wrote: On Tue, 19 Jul 2016 06:20 am, alister wrote: I suggest next time you stay awake during lessons. That's an uncalled for nasty comment. You don't know the O.P's issues or why he is having difficulty. because he has failed to provide any context. the question as phrased looks exactly like a homework question a tutor would set after a lesson introducing classes It looked a lot like some posts from earlier this year. -- https://mail.python.org/mailman/listinfo/python-list
Re: Request for help
On Tue, 19 Jul 2016 13:06:39 +1000, Steven D'Aprano wrote: > On Tue, 19 Jul 2016 06:20 am, alister wrote: > >> I suggest next time you stay awake during lessons. > > That's an uncalled for nasty comment. You don't know the O.P's issues or > why he is having difficulty. because he has failed to provide any context. the question as phrased looks exactly like a homework question a tutor would set after a lesson introducing classes -- If you keep anything long enough, you can throw it away. -- https://mail.python.org/mailman/listinfo/python-list
Re: Request for help
On Mon, 18 Jul 2016 07:50 pm, Eric kago wrote: > Hi Pythoners > > I need help in understanding hoe to put up the code to the following > command Hi Eric, You might find that the "Tutor" mailing list is better for simple questions like this: https://mail.python.org/mailman/listinfo/tutor Remember, for help with home work, show the code you already have. >- Create a constructor that takes in an integer and assigns this to a >`balance` property Talking about a "constructor" means that you need to have a class. We define a class with the "class" keyword: class Myclass: pass To give it a constructor method, you need to use the __init__ method, or sometimes __new__. In this case, I think __init__ is what you want. Do you know how to define methods inside a class? Remember that __init__ is spelled with TWO underscores at the start and end. -- Steven “Cheer up,” they said, “things could be worse.” So I cheered up, and sure enough, things got worse. -- https://mail.python.org/mailman/listinfo/python-list
Re: Request for help
On Tue, 19 Jul 2016 06:20 am, alister wrote: > I suggest next time you stay awake during lessons. That's an uncalled for nasty comment. You don't know the O.P's issues or why he is having difficulty. -- Steven “Cheer up,” they said, “things could be worse.” So I cheered up, and sure enough, things got worse. -- https://mail.python.org/mailman/listinfo/python-list
Re: Request for help
On Mon, 18 Jul 2016 12:50:04 +0300, Eric kago wrote: > Hi Pythoners > > I need help in understanding hoe to put up the code to the following > command > > >- Create a constructor that takes in an integer and assigns this to a >`balance` property > > > > > Regards, > > Eric Kago +254(0)714249373 Nairobi Kenya I suggest next time you stay awake during lessons. -- I treasure this strange combination found in very few persons: a fierce desire for life as well as a lucid perception of the ultimate futility of the quest. -- Madeleine Gobeil -- https://mail.python.org/mailman/listinfo/python-list
Re: Request for help
Hi Pythoners I need help in understanding hoe to put up the code to the following command - Create a constructor that takes in an integer and assigns this to a `balance` property Regards, Eric Kago +254(0)714249373 Nairobi Kenya -- https://mail.python.org/mailman/listinfo/python-list
Re: request for help
On 2/18/2013 2:42 PM, leonardo selmi wrote: i saved the above program from python shell into a file as "circle.py" . Which copied too much into the file. Edit circle.py until it is a proper python program. My initial guess was that you copied the >>> prompts, but you later message shows that it was the welcome header. Header and prompts all need to go. Idle makes it easier to cut and paste a single statement from its shell to an editor window and then save. Or start your code in an editor, such as IDLE's. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: request for help
leonardo libero.it> writes: > here is the error message: > [...] Okay, now we are on the road to solving this problem. But first we need to take a slight detour and learn about python packaging, because no matter what the current error is, naming a module "circle" and then throwing it naked out into the "Python module wilderness" is complete folly; i can assure you! What is a Python package? A python package is simply another layer of namespace that protects our symbols from clashing; in this case: module identifiers. Even noobs understand that function bodies and class bodies (bka: object definitions) protect code from outside influences, and that modules protect the symbols contained in one module from the symbols contained in /other/ modules, however, we still must protect module identifiers somehow. How do we do this? Packages to the rescue! Your "circle.py" module needs to be under the "protective care" of a specialized package named "geom2d" , which itself should be under the care of a specialized package named "math", which itself should be under the "global blanket" of a personal library package named "insertUniqueNameHere"! This is how we protect module symbols whilst simultaneously employing a logical structure in our code. Impatient Ivan exclaimed: "So how the heck do i create the package Rick?" Steps to create the entire package hierarchy: Note: All package and modules names should be lowercase! 1a. Create a folder named "mylib" on the Python search path. 1b. Convert the "mylib" folder into a package by adding a file named: "__init__.py" This will be your personal package for containing your personal modules. 2a. Inside the "mylib" folder create another folder called "math" 2b. Convert the "mylib\math" folder to a package by adding a file named "__init__.py". 3a. Inside the "mylib\math" folder create another folder named "geom2d" 3b. Convert the "mylib\math\geom2d" folder to a package by adding a file named "__init__.py". 4. Inside the "mylib\math\geom2d" folder create a new file named "circlelib.py". This is where you will place the code for computing circle data. Later you will probably write something more useful, but for now this module is the best you have. Now, you'll need to import the circlelib for use and this is how you do it: ## START CODE ## from mylib.math.geom2d.circlelib import area, circumference area(blah) circumference(blah) ## END CODE ## >From now on, if you create any more modules that deal with maths (or a subset >of math: geom) you have a place to store them intelligently. There is quite a bit more to Python packages but what i describe above is the most fundamental aspect. Back to your exception Did correcting the indentation fix the problem? If not, what is the next error you get? -- http://mail.python.org/mailman/listinfo/python-list
Re: request for help
On 02/18/2013 12:14 PM, leonardo wrote: thanks guys and sorry for my incomplete datas, here is the error message: Traceback (most recent call last): File "", line 1, in import circle File "circle.py", line 1 Python 2.7.3 (v2.7.3:70274d53c1dd, Apr 9 2012, 20:52:43) ^ SyntaxError: invalid syntax If I read this error message correctly, I don't think the contents of circle.py are at all what you claim. It looks like the first line of circle.py contains the text "Python 2.7.3 ..." which is certainly not what you intended or claimed. Please examine the contents of circle.py very carefully. thanks for any help! Il giorno 18/feb/2013, alle ore 20:59, Stefan Holdermans ha scritto: Leonardi, i saved the above program from python shell into a file as "circle.py" . when i type "import circle" i get error.. Next time, please mention what kind of error you're getting. Was it an indentation error? Because, as you pasted it, your code would lead to one. If I fix the indentation, as in import math def area(radius): return math.pi * radius**2 def circumference(radius): return 2 * math.pi * radius it works fine for me. HTH, Stefan -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: request for help
thanks guys and sorry for my incomplete datas, here is the error message: Traceback (most recent call last): File "", line 1, in import circle File "circle.py", line 1 Python 2.7.3 (v2.7.3:70274d53c1dd, Apr 9 2012, 20:52:43) ^ SyntaxError: invalid syntax thanks for any help! Il giorno 18/feb/2013, alle ore 20:59, Stefan Holdermans ha scritto: > Leonardi, > >> i saved the above program from python shell into a file as "circle.py" . >> when i type "import circle" i get error.. > > > Next time, please mention what kind of error you're getting. > > Was it an indentation error? Because, as you pasted it, your code would lead > to one. > > If I fix the indentation, as in > > import math > > def area(radius): > return math.pi * radius**2 > > def circumference(radius): > return 2 * math.pi * radius > > it works fine for me. > > HTH, > > Stefan > -- > http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: request for help
Leonardi, > i saved the above program from python shell into a file as "circle.py" . when > i type "import circle" i get error.. Next time, please mention what kind of error you're getting. Was it an indentation error? Because, as you pasted it, your code would lead to one. If I fix the indentation, as in import math def area(radius): return math.pi * radius**2 def circumference(radius): return 2 * math.pi * radius it works fine for me. HTH, Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: request for help
On 02/18/2013 11:42 AM, leonardo selmi wrote: pls i need help: i have copied the following from a book and tried to make it work: import math def area(radius): return math.pi * radius**2 def circumference(radius): return 2 * math.pi * radius i saved the above program from python shell into a file as "circle.py" . when i type "import circle" i get error.. kind regards First, you shouldn't ask us to help you fix an error without telling us what the error is! You should also tell us what version of Python and what system (Windows? Linux? ...) , and anything more that can help us understand what you did and what failed. So this is just guesswork: Spaces are important in Python. The body of a function **must** be indented. If you do have the indents in your code, and they were just lost in the process of cutting and pasting and emailing, the we really do need more information. def area(radius): return math.pi * radius**2 def circumference(radius): return 2 * math.pi * radius -- http://mail.python.org/mailman/listinfo/python-list
Re: request for help
leonardo selmi icloud.com> writes: > [...] > i saved the above program from python shell into a file as > "circle.py" . when i type "import circle" i get error.. Urm... would you be so kind as to copy and paste the error message verbatim? You have obvious syntax errors in this code due to improper indentation, but take a word of advice from the Python Zen: "In the face of ambiguity, refuse the temptation to guess" So let's have a look-see at that error message, shall we? -- http://mail.python.org/mailman/listinfo/python-list
Re: request for help
Is this exactly how it shows in your shell? If so, it seems you need to indent your methods. # import math def area(radius): return math.pi * radius**2 def circumference(radius): return 2 * math.pi * radius # *Matt Jones* On Mon, Feb 18, 2013 at 1:42 PM, leonardo selmi wrote: > pls i need help: > > i have copied the following from a book and tried to make it work: > > import math > > def area(radius): > return math.pi * radius**2 > > def circumference(radius): > return 2 * math.pi * radius > > i saved the above program from python shell into a file as "circle.py" . > when i type "import circle" i get error.. > > > kind regards > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: Request for help with Image color space conversion
> > ...where the image data is loaded into a numpy array > (1600x1200x3)... One comment: that is a big array, too big for the cache memory. I know that in these cases it makes a difference how many times the slices of the array are loaded and unloaded from RAM onto cache. One issue is that a 2D array l[i,j] is actually a 1D array: either l[i,j]=l[i*N+j] or l[i,j]=l[j*N+i] I don't know which in python/numpy. In the first case, when you fix i and change j, you get consecutive positions in the underlying 1D array, and they all belong to the same slice, which is loaded onto cache very fast as a block. If you do the opposite, you are making jumps to distant positions in the array (not a slice), and performance suffers. In gimp, for example, the underlying array is split into 'tiles', which are 64x64 pixel regions that can be loaded/unloaded as a block. And that's about all I know on the issue. So it ma -- http://mail.python.org/mailman/listinfo/python-list
Re: Request for help with Image color space conversion
ttest wrote: >> Reimplement colorsys.rgb_to_hsv() such that it operates on arrays instead of >> scalars. Only minor modifications are necessary. >> >> -- >> Robert Kern > > Thanks! I'll try and see if a newcomer like me can get his head > around the array-centric modifications to colorsys. If you hit any roadblocks, drop in on numpy-discussion, and we'll help you out. http://www.scipy.org/Mailing_Lists -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: Request for help with Image color space conversion
> Reimplement colorsys.rgb_to_hsv() such that it operates on arrays instead of > scalars. Only minor modifications are necessary. > > -- > Robert Kern Thanks! I'll try and see if a newcomer like me can get his head around the array-centric modifications to colorsys. -- http://mail.python.org/mailman/listinfo/python-list
Re: Request for help with Image color space conversion
ttest wrote: > Hello, > > I'm working on an image processing project using the Python Imaging > Library along with numpy. Right now, I'm trying to build a speedy > script for converting whole images between the RGB and the HSV (a.k.a. > HSB) color spaces. Unfortunately, the code I've made so far runs > dreadfully slow with even moderate-sized images. > > I'm under the impression that the crux of the problem is the fact that > PIL's point method operates on only one band at a time, and to do a > proper color space conversion, you need information about all three > bands in a particular problem. This has forced me to do an awkward > work-around where the image data is loaded into a numpy array > (1600x1200x3), and a dinky for-loop run runs through the array picking > up RGB values, converting to HSV, and dumping the results back into > another array. > > How can I make this more efficient? Reimplement colorsys.rgb_to_hsv() such that it operates on arrays instead of scalars. Only minor modifications are necessary. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: Request for help on naming conventions
On Monday 13 June 2005 03:59 am, Steven D'Aprano wrote:
> Are there any useful naming conventions for modules, classes and functions?
>
> For instance, should I name functions as verbs and classes as nouns?
Hmm. Okay, here's a few I use:
Classes are generally: Capitalized or CapWords and I use nouns.
Unless it's a "mix-in" in which case, I use adjectives. This mirrors
usage in the Zope sources, BTW.
Method names are either: funkyCaps (Zope uses this) or
lower_case_with_underscores.
I use verb names for methods and functions with very few exceptions.
I use nouns or occasionally adjectives for attributes.
Constants or enumeration values are ALLCAPS or ALL_CAPS, and
usually I define them within a namespace with a descriptive, all lower
case name (a trivial class). The enumeration is usually abbreviated,
but would be an adjective, e.g.:
color.RED
I use *plural* names for lists and tuples, but singular names for
mappings. This is so that I can use the singular in the loop:
for book in books:
pass
But I use single character variables in list comprehensions (and
generators, except I haven't used them yet):
late_books = [b for b in books if b.duedate < datetime.now()]
I also use single-character names in highly mathematical code:
def dot_product(a,b):
return a.x*b.x + a.y*b.y + a.z*b.z
But if a variable is going to be used more than about 20 lines
away from where it is defined, I use a descriptive word instead.
I like to use Capital or CapWords for modules, too, although I'm
beginning to wonder about that practice.
I really hate redundancy like this:
Topic.create_topic()
and usually prefer:
Topic.create()
which of course means, I have to qualify things a lot in my code.
This has never been an issue, but if it did, I would just introduce
an intermediary like this ("_" for "."):
Topic_create = Topic.create
After that, it's kind of case-by-case. Do read PEP 8, too, of
course.
--
Terry Hancock ( hancock at anansispaceworks.com )
Anansi Spaceworks http://www.anansispaceworks.com
--
http://mail.python.org/mailman/listinfo/python-list
Re: Request for help on naming conventions
Steven D'Aprano wrote: > Are there any useful naming conventions for modules, classes and > functions? > > For instance, should I name functions as verbs and classes as nouns? > > eg > class Transformer(): > pass > > def transform(): > do_stuff > > What about the module name? transformations.py or transform.py? You probably want to read the PEP 8, "Style Guide for Python Code": http://www.python.org/peps/pep-0008.html > What do people do with their own code? Do folks find that being > consistent helps them remember what is what, or do you name objects > whatever feels right at the time? Naming convention are mostly a matter of personal taste (unless you are working in a larger team, where there are some official conventions that must be followed). So I would say the 'feels right' is the most important factor. -- Benjamin Niemann Email: pink at odahoda dot de WWW: http://www.odahoda.de/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Request for Help in OpenSourcing a Project
www.sourceforge.net -- http://mail.python.org/mailman/listinfo/python-list
