[Tutor] Assertion Error
I tried this statement to store in RDF form
store=TripleStore()
But i'm getting this error
Traceback (most recent call last):
File "", line 1, in
store=TripleStore()
File "C:\Users\Administrator\Desktop\TripleStore.py", line 13, in __init__
super(TripleStore, self).__init__(backend=backend)
File "build\bdist.win32\egg\rdflib\Graph.py", line 1008, in __init__
super(BackwardCompatGraph, self).__init__(store=backend)
File "build\bdist.win32\egg\rdflib\Graph.py", line 815, in __init__
assert self.store.context_aware, ("ConjunctiveGraph must be backed by"
AssertionError: ConjunctiveGraph must be backed by a context aware store.
plz help
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Re: [Tutor] Problems with iterations and breaking loops
"Karjer Jdfjdf" wrote
In reality I have to do this for a much larger dataset
(eg 1 range * 10 = a lot), so the for v1, v2 in
list_of_tuples doesn't work because it is too large for it.
What does the size have to do with it?
v1,v2 in list_of_tuples will only unpack one tuple at a
time regardless of how big the list is.
I've tried to put it in a def, but:
Take the outer loop out of the function.
The point of functions is to break the problem down into
manageable chunks.
You should probably have 3 functions here:
1) to do the calculation on a single element
2) to apply function(1) to each item in the tuple list
3) a function to apply function(") from min to max
That makes your code look like
def function3(min,max)
for n in range(min,max):
function2(val, t_lst)
def function2((val, tuples)
for tuple in tuples:
function3(val,tuple)
def function(val,pair)
# whatever calc you need
That way you can test each function in turn and
stop the nested loops from dominating the logic.
def perform_calculations2(n, nmax, value, list_of_tuples, ):
#this works too good. It returns 10 times the correct 30 values
Because you have repeated the outer loop inside the function.
Get rid of it.
something = []
for i2 in xrange(n, int(nmax+1)):
And please stop calling int() when the values are already ints.
for t in list_of_tuples:
v1 = t[0]
v2 = t[1]
something.append(str(i2) + "\tdoes something for\t" + str(v2))
return something
The above is all you need in your function.
HTH,
--
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/
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[Tutor] Self-intro and two short newbie questions
Hi all, I've committed myself to learning Python and have started reading "Learning Python" (Mark Lutz) and looking through various online resources. My career so far has involved a little high school teaching and about 10 years of translating Japanese to English, but no programming or coding. I've also joined this list today and this is my first post. My aim is to be able to create Python programs, specifically "activities" that work on the OLPC's XO laptops and SoaS (Sugar on a Stick). My questions are: how long would you estimate it to take and how complicated would it be to create the following as Python programs? (I know it varies depending on the person, but for example, how long would it take _you_?) (i) a simple guitar tuning program involving an image of a guitar and the playing of each of the standard strings of a guitar (E, A, D, G, B, E) upon key input by the user (something similar to this: http://www.gieson.com/Library/projects/utilities/tuner/ (page is 782kb to open)) and (ii) a very basic turtle art program with an intentionally limited set of commands and on-screen display words (say, a total of 30 to 50 specific strings), wherein the entire set of strings is offered to the user (perhaps at first use of the program) in a format that enables easy and full localization of the program so long as each of the strings is translated appropriately and inputted to the program. I know of turtle.py and xturtle.py, but I'm thinking of starting something from scratch. It's the easy localization I'm interested in. Hope these questions are appropriate. I'm grateful to be able to ask them here. Kevin (in Australia) ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] parsing a "chunked" text file
Karim Liateni, 04.03.2010 01:23: Steven D'Aprano wrote: def skip_blanks(lines): """Remove leading and trailing whitespace, ignore blank lines.""" for line in lines: line = line.strip() if line: yield line Is there a big difference to write your first functions as below because I am not familiar with yield keyword? def skip_blanks(lines): """Remove leading and trailing whitespace, ignore blank lines.""" return [line.strip() in lines if line.strip()] Yes, a *big* difference in the true sense of the word. Your code (assuming you meant to write "... for line in ..." ) evaluates the entire list comprehension before returning from the call. Steven's code returns a generator that only handles one line (or a couple of empty lines) at a time. So, assuming that this runs against a large file, Steven's code uses only a constant amount of memory, compared to the whole file in your case, and is likely also a lot faster than your code as it involves less looping. Stefan ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] parsing a "chunked" text file
On Thu, Mar 18, 2010 at 12:54 PM, Stefan Behnel wrote: > Karim Liateni, 04.03.2010 01:23: > > Yes, a *big* difference in the true sense of the word. Your code (assuming > you meant to write "... for line in ..." ) evaluates the entire list > comprehension before returning from the call. Steven's code returns a > generator that only handles one line (or a couple of empty lines) at a time. > So, assuming that this runs against a large file, Steven's code uses only a > constant amount of memory, compared to the whole file in your case, and is > likely also a lot faster than your code as it involves less looping. > Though, if you changed the brackets into parentheses, you'd get a generator expression, which *is* equivalent to Steven's version, except that it calls strip() twice, which is a bit wasteful. If the unnecessary extra call bothers you, you could do one of two things: 1) Learn how the yield keyword works. You should do this. It's an awesome feature, and you'll come across it many more times. 2) go functional and import itertools. ifilter with a generator expression, like so (pure functional programmers can also use imap instead of the generator expr., which might be faster. profile to be sure) def skip_blanks(lines): return ifilter(None, (l.strip() for l in lines)) Very short, has all the memory and speed benefits of the generator. Personally I really like terse functional programming like this, though I believe the general consensus in the python community is that imperative alternatives are usually clearer to read. If you want to know more about the yield keyword: A terse description (assumes that you know how iterators work) is here: http://docs.python.org/tutorial/classes.html#generators A more detailed description of iterators and generators can be found here: http://www.ibm.com/developerworks/library/l-pycon.html Hugo ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Self-intro and two short newbie questions
On Thu, Mar 18, 2010 at 6:42 AM, Kevin Kirton wrote: > Hi all, > > I've committed myself to learning Python and have started reading > "Learning Python" (Mark Lutz) and looking through various online > resources. > My career so far has involved a little high school teaching and about > 10 years of translating Japanese to English, but no programming or > coding. > Welcome to python! I've never read that book, but I hear it's pretty good. > > I've also joined this list today and this is my first post. > > My aim is to be able to create Python programs, specifically > "activities" that work on the OLPC's XO laptops and SoaS (Sugar on a > Stick). > I don't know anything about the SoaS, but I do know a teeny bit about OLPC's XO laptops. Python is a great tool for several reasons - among them the availability of source code allows experimentation by XO users, which is in line with the XO philosophy. > > My questions are: how long would you estimate it to take and how > complicated would it be to create the following as Python programs? (I > know it varies depending on the person, but for example, how long > would it take _you_?) > > (i) a simple guitar tuning program involving an image of a guitar and > the playing of each of the standard strings of a guitar (E, A, D, G, > B, E) upon key input by the user > (something similar to this: > http://www.gieson.com/Library/projects/utilities/tuner/ (page is 782kb > to open)) > and > I could probably make something similar to that in less than a few hours, and most of it would be learning how to output the sound. If I had that knowledge I could make a VERY basic one in ~30 minutes, and make one that's rather nice within an hour or two. > (ii) a very basic turtle art program with an intentionally limited set > of commands and on-screen display words (say, a total of 30 to 50 > specific strings), wherein the entire set of strings is offered to the > user (perhaps at first use of the program) in a format that enables > easy and full localization of the program so long as each of the > strings is translated appropriately and inputted to the program. I > know of turtle.py and xturtle.py, but I'm thinking of starting > something from scratch. It's the easy localization I'm interested in. > That would probably take a little longer if only the more complicated design. That sounds like a project that I would probably work on over the course of a few days - some research, some design, some coding. Both of these projects are very possible for the beginner/novice with a little education (I'd start on the guitar tuner first as its level of complexity is much lower). HTH, Wayne ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Assertion Error
On 3/17/2010 11:02 PM sitharak said...
I tried this statement to store in RDF form
This is too specialized for this list. I couldn't find a dedicated news
group for this project, but there is an IRC support channel -- see
http://en.wikipedia.org/wiki/RDFLib#Support
HTH,
Emile
store=TripleStore()
But i'm getting this error
Traceback (most recent call last):
File "", line 1, in
store=TripleStore()
File "C:\Users\Administrator\Desktop\TripleStore.py", line 13, in __init__
super(TripleStore, self).__init__(backend=backend)
File "build\bdist.win32\egg\rdflib\Graph.py", line 1008, in __init__
super(BackwardCompatGraph, self).__init__(store=backend)
File "build\bdist.win32\egg\rdflib\Graph.py", line 815, in __init__
assert self.store.context_aware, ("ConjunctiveGraph must be backed by"
AssertionError: ConjunctiveGraph must be backed by a context aware store.
plz help
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Re: [Tutor] Self-intro and two short newbie questions
On Thu, 18 Mar 2010 22:42:05 +1100 Kevin Kirton wrote: > My questions are: how long would you estimate it to take and how > complicated would it be to create the following as Python programs? (I > know it varies depending on the person, but for example, how long > would it take _you_?) My opinion: The time required to make a working app (with exactly the same features, in the same language) by 2 trained programmers can easily range from 1 to 10. The time required to make a given app by a given programmer can easily range from 1 to 10 depending on the level of sophistication. "Devil hides in the details." ;-) Denis vit e estrany spir.wikidot.com ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Self-intro and two short newbie questions
"Kevin Kirton" wrote know it varies depending on the person, but for example, how long would it take _you_?) (i) a simple guitar tuning program involving an image of a guitar and the playing of each of the standard strings of a guitar (E, A, D, G, B, E) upon key input by the user For a professional standard finish, working full time I'd be looking at a day or two. (ii) a very basic turtle art program with an intentionally limited set of commands and on-screen display words (say, a total of 30 to 50 specific strings), wherein the entire set of strings is offered to the user (perhaps at first use of the program) in a format that enables easy and full localization of the program so long as each of the strings is translated appropriately and inputted to the program. I know of turtle.py and xturtle.py, but I'm thinking of starting something from scratch. It's the easy localization I'm interested in. This might be three days. You could do both projects to a good standard in a week. However if you need to include things like user manuals, help system, online support(auto updates) etc plus installation programs (Dunno if thats relevant to OLPC etc) You could easily double the time and effort. HTH, Alan G. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] movement controls
A little stuck and could do with any sudjestions.
Aim:-
When the character goes past the middle of the screen, the background & level
move downwards so the character can get to higher places, think sonic the
hedgehog.
This is the bit I'm having problems with, I can get the character to get to the
center, the background moves up & down but the character won't go back down
when the level returns to normal height.
if bkGroundRect['rect'].top < 0 and charRect['rect'].top <
winCenterRect.top:
bkGroundRect['rect'].top += spY
platRect['rect'].top += spY
jumpRect.top += spY
charRect['dir'] = STOP
if levelRect['rect'].bottom > winHeight and charRect['rect'].centery ==
winCenterx:
bkGroundRect['rect'].bottom -= spY
platRect['rect'].bottom -= spY
#jumpRect.bottom -= spY
charRect['dir'] = STOP
#--this won't execute ? --#
if levelRect['rect'].bottom <= winHeight:
if charRect['rect'].centery >= winCenterx and charRect['rect'].centerx
< jumpRect.centerx:
charRect['dir'] = DOWN
I've included the whole code as a note pad so the above makes more sense, don't
worry about all the comments, that's just for my convenience.
Thanks guys
Mark
'knight meets wall, wall won't let knight pass, knight says 'neh'
import pygame, sys, time
from pygame.locals import *
pygame.init()
#--Display--#
winWidth = 400
winHeight = 400
winCenterx = int(winWidth / 2)
winCentery = int(winHeight / 2)
window = pygame.display.set_mode((winWidth, winHeight), 0, 32)
#--Display--#
#--Images--#
BackgroundImage = pygame.image.load('Background.jpg')
FloorImage = pygame.image.load('Floor.jpg')
BallImage = pygame.image.load('Ball.jpg')
#--Images--#
#--Movement Variables--#
forward = False
backward = False
jump = False
UP = 8
DOWN = 2
STOP = 5
spX = 3
spY = 5
#--Movement Variables--#
#--Level Rects--#
bkGroundScImage = pygame.transform.scale(BackgroundImage, (1000, 1000))
bkGroundRect = {'rect':pygame.Rect(0, -650, 1000, 1000), 'dir':UP}
levelScImage = pygame.transform.scale(FloorImage, (1000, 50))
levelRect = {'rect':pygame.Rect(0, winHeight - 50, 1000, 50), 'dir':DOWN}
platScImage = pygame.transform.scale(FloorImage, (100, 25))
platRect = {'rect':pygame.Rect(75, 270, 100, 25), 'dir':DOWN}
platScImage1 = pygame.transform.scale(FloorImage, (100, 25))
platRect1 = {'rect':pygame.Rect(225, 250, 100, 25), 'dir':UP}
platScImage2 = pygame.transform.scale(FloorImage, (100, 25))
platRect2 = {'rect':pygame.Rect(375, 200, 100, 25), 'dir':UP}
platScImage3 = pygame.transform.scale(FloorImage, (100, 25))
platRect3 = {'rect':pygame.Rect(575, 150, 100, 25), 'dir':UP}
platScImage4 = pygame.transform.scale(FloorImage, (100, 25))
platRect4 = {'rect':pygame.Rect(675, 150, 100, 25), 'dir':UP}
platScImage5 = pygame.transform.scale(FloorImage, (100, 25))
platRect5 = {'rect':pygame.Rect(575, 0, 100, 25), 'dir':UP}
platScImage6 = pygame.transform.scale(FloorImage, (100, 25))
platRect6 = {'rect':pygame.Rect(375, 0, 100, 25), 'dir':UP}
#--Level Rects--#
#--Caracter Rects--#
charScImage = pygame.transform.scale(BallImage, (50, 50))
charRect = {'rect':pygame.Rect(20, 300, 50, 50), 'dir':DOWN}
jumpScImage = pygame.transform.scale(FloorImage, (50, 140))
jumpRect = pygame.Rect(20, 210, 50, 140)
winCenterRectScImage = pygame.transform.scale(FloorImage, (60, 60))
winCenterRect = pygame.Rect(winCenterx - 30, winCentery - 30, 60, 60)
#--Caracter Rects--#
#--Collision Variables--#
solidX = int(charRect['rect'].width - spX - spX - 2)
solidY = int(charRect['rect'].height - spY - spY- 1)
#--Collision Variables--#
while True:
#--Level & scenery--#
window.blit(bkGroundScImage, bkGroundRect['rect'])
window.blit(levelScImage, levelRect['rect'])
window.blit(platScImage, platRect['rect'])
window.blit(platScImage1, platRect1['rect'])
window.blit(platScImage2, platRect2['rect'])
window.blit(platScImage3, platRect3['rect'])
window.blit(platScImage4, platRect4['rect'])
window.blit(platScImage5, platRect5['rect'])
window.blit(platScImage6, platRect6['rect'])
levelRect['rect'].top = bkGroundRect['rect'].bottom
#--Level & scenery--#
#--Character--#
window.blit(winCenterRectScImage, winCenterRect)
winCenterRect.center = (winCenterx, winCentery)
window.blit(jumpScImage, jumpRect)
jumpRect.centerx = charRect['rect'].centerx
window.blit(charScImage, charRect['rect'])
#--Character--#
#--Input controls--#
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type == KEYDOWN:
if event.key == K_RIGHT:
forward = True
backward = False
if event.key == K_LEFT:
backward = True
forward = False
if event.key == K_UP:
jump = True
if event.type == KEYUP:
if event.key == K
Re: [Tutor] movement controls
You should probably decouple the view from the model - have the character move around in a 2d plane in the model and then just draw the level in a certain area around the 2d coordinates of the character. On Thu, Mar 18, 2010 at 6:51 PM, wrote: > A little stuck and could do with any sudjestions. > > Aim:- > When the character goes past the middle of the screen, the background & > level move downwards so the character can get to higher places, think sonic > the hedgehog. > > This is the bit I'm having problems with, I can get the character to get to > the center, the background moves up & down but the character won't go back > down when the level returns to normal height. > > if bkGroundRect['rect'].top < 0 and charRect['rect'].top < > winCenterRect.top: > > bkGroundRect['rect'].top += spY > platRect['rect'].top += spY > jumpRect.top += spY > charRect['dir'] = STOP > > > if levelRect['rect'].bottom > winHeight and charRect['rect'].centery == > winCenterx: > bkGroundRect['rect'].bottom -= spY > platRect['rect'].bottom -= spY > #jumpRect.bottom -= spY > charRect['dir'] = STOP > > #--this won't execute ? --# > if levelRect['rect'].bottom <= winHeight: > if charRect['rect'].centery >= winCenterx and > charRect['rect'].centerx < jumpRect.centerx: > charRect['dir'] = DOWN > > I've included the whole code as a note pad so the above makes more sense, > don't worry about all the comments, that's just for my convenience. > > Thanks guys > > Mark > > 'knight meets wall, wall won't let knight pass, knight says 'neh' > > > ___ > Tutor maillist - Tutor@python.org > To unsubscribe or change subscription options: > http://mail.python.org/mailman/listinfo/tutor > > ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Self-intro and two short newbie questions
Thanks very much for the responses. I feel encouraged now to try to create the guitar tuner program by myself first, and then the simple turtle art program after that. It's kind of both exhilarating and daunting that I don't know exactly where to start at the moment, but that's the fun of learning I guess. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
