Re: Changing the module not taking effect in calling module
Gopal wrote: > I've a module report.py having a set of funtions to open/close/write > data to a log file. I invoke these functions from another module > script.py. > > Whenever I'm changing something in report.py, I'm running the file > (however, it has not effect). After that I'm running script.py again. > However, the output is not taking effect. > > If I shut the IDLE interpreter and all the other files and then reopen > again; and then run script.py, the output is taking effect. > > Is there any way to improve it? I'm new to Python. If I understand you correctly, you are importing your module report in script.py. If so, you need reload. When in IDLE, you have a python process running, in which you execute your program. The first time you run script.py after starting IDLE, your module report is imported from file. The next time you run script.py, there is already a module named report in memory. Then the corresponding file will not be executed again. Instead, the one in memory will be used. What I do when I am developing a module for a program is that I both import and reload the module in my main file. Once I think I am done developing, I remove the reload statement. So, in your script.py, I would write: import report reload(report) HTH /MiO -- http://mail.python.org/mailman/listinfo/python-list
Dynamic generation of doc-strings of dynamically generated classes
Hi!
I've asked Google, but have not found any useful information there.
Situation: I have a base class, say
>>> class base(object):
ImportantClassAttribute = None
Now, I want to dynamically generate subclasses of base. That's not a
problem. However, I very much want those subclasses to have individual
doc-strings. More precicely, I want that important class attribute to be
reflected in the doc-string. That's the problem. The only way I've
managed to accomplish that is something like the following.
>>> ImportantClassAttribute = 7
>>> docString = 'The case %s.' % (ImportantClassAttribute,)
>>> exec('''class new(base):
"""%s"""
pass ''' % (docString,))
>>> new.ImportantClassAttribute = ImportantClassAttribute
>>> new.__doc__
'The case 7.'
This works as intended. The subclasses do get the doc-strings I want
them to have, and I can live with this solution. But: This solution does
not strike me as especially beautiful or readable. My first naïve
attempt was instead the following.
>>> class new(base):
pass
>>> new.ImportantClassAttribute = 7
>>> new.__doc__ = ('The case %(ImportantClassAttribute)s.'
% new.__dict__)
Traceback (most recent call last):
File "", line 1, in -toplevel-
new.__doc__ = ('The case %(ImportantClassAttribute)s.'
TypeError: attribute '__doc__' of 'type' objects is not writable
This is readable to me, but apparently not the way to go, since I'm not
allowed to replace the doc-string like this. I've also tried a number of
other ways, but they all stumble on similar reasons.
Any ideas? Am I stuck with the clumsy exec-solution, or are there other
ways to dynamically generate doc-strings of classes?
/MiO
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Re: Dynamic generation of doc-strings of dynamically generated classes
Alex Martelli wrote:
> The best way to make classes on the fly is generally to call the
> metaclass with suitable parameters (just like, the best way to make
> instances of any type is generally to call that type):
>
> derived = type(base)('derived', (base,), {'__doc__': 'zipp'})
and George Sakkis said something similar.
Thanks, both of you. As I expected, there was a much better way than my
clumsy way. Anyway, this took me to section 3.3.3 in the reference
manual, and that will help me further.
Thanks again. Back to the keyboard!
/MiO
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Re: Would there be support for a more general cmp/__cmp__
Antoon Pardon wrote: > Op 2005-10-20, Duncan Booth schreef <[EMAIL PROTECTED]>: > >>Antoon Pardon wrote: >> >> >>>The problem now is that the cmp protocol has no way to >>>indicate two objects are incomparable, they are not >>>equal but neither is one less or greater than the other. >> >>If that is the case then you implement __eq__ and __ne__ to return >>True/False and make cmp throw an exception. I don't see any need to extend >>the cmp protocol. > > > That is not sufficient. There are domains where an order exists, but not > a total order. So for some couples of elements it is possible to say > one is less than the other, but not for all such couples. > > Your solution wouldn't allow for such a case. Wouldn't the full power of rich comparisons be enough? See section 3.3.1 in Python Reference Manual: http://www.python.org/doc/2.4.2/ref/customization.html See methods __lt__, __le__, __eq__, __ne__, __gt__, __ge__. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: how to stop a loop with ESC key? [newbie]
Fredrik Lundh wrote: > works for me, when running it from a stock CPython interpreter in a windows > console window, with focus set to that window. > > what environment are you using? Could be IDLE. The code Fredrik proposed works well for me in the Python console window, but not in IDLE (thats under XP). I guess that IDLE makes use of msvcrt itself. Let's remember that the OP describes himself as a newbie in the subject, so he might not know the difference between those two interactive environments. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: any python module to calculate sin, cos, arctan?
Shi Mu wrote: > any python module to calculate sin, cos, arctan? Try module math. Or cmath if you want the functions to be aware of complex numbers. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie - How do I import automatically?
[EMAIL PROTECTED] wrote: > I tried to put the line > from btools import * > in several places in PyShell.py > but to now avail. It does not work, IDLE does not execute it??? IDLE definitely executes PyShell.py upon startup, since IDLE does not even appear on the screen if there is an error in that file. The following seems to work for me, in PyShell.py. After importing both sys and os, sys.modules['__main__'].__dict__['os'] = os Then, if I start IDLE, the module os is directly available. HTH /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie - How do I import automatically?
[EMAIL PROTECTED] wrote: > I tried to do it on my computer (win XP). I put an extra line in > PyShell.py > [snip] > # test > sys.modules['__main__'].__dict__['os'] = os > [snip] > Then when I start idle I get > > IDLE 1.1.1 > dir() > > ['__builtins__', '__doc__', '__name__'] > > > So I don't see 'os' > > Do you see 'os' on your computer. If yes, what could be the difference? Yes, I do. The following is with IDLE 1.0.3 and Python 2.3.4 on WinXP. Without the line in PyShell.py: IDLE 1.0.3 No Subprocess >>> dir() ['__builtins__', '__doc__', '__file__', '__name__', 'main'] With the line in PyShell.py: IDLE 1.0.3 No Subprocess >>> dir() ['__builtins__', '__doc__', '__file__', '__name__', 'main', 'os'] >>> os I know nothing about the details of how IDLE work. All I know is what I have reported here. I was simply inspired by the following remark from Claudio Grondi up-thread: > edit the first lines of %SystemDrive%\Python24\Lib\idlelib\PyShell.py I guess that PyShell.py is imported as a module by IDLE at startup. One thought, though: Du you have more than one Python installed? If so: Could it be that you are editing the wrong PyShell.py? Regards /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie - How do I import automatically?
[EMAIL PROTECTED] wrote: >> I tried to do it on my computer (win XP). I put an extra line in >> PyShell.py >> [snip] >> # test >> sys.modules['__main__'].__dict__['os'] = os >> [snip] >> Then when I start idle I get >> >> IDLE 1.1.1 >> > dir() >> >> >> ['__builtins__', '__doc__', '__name__'] >> >> >> So I don't see 'os' >> >> Do you see 'os' on your computer. If yes, what could be the difference? > > I answered: > Yes, I do. [snip details] I have to step back a bit. IDLE seems to work differently depending on how it is started. My comments above hold when I start IDLE by right-clicking on a python-file and choosing "Edit with IDLE". If I instead start IDLE itself (from the windows start-menu) I get the same behaviour as you do, namely no os around. Another difference, which I've noted before is that shell restart is only available when IDLE has been started this way. All this seems to be handled in PyShell.py, but I do not have the time to trace that in any detail. Regards /MiO -- http://mail.python.org/mailman/listinfo/python-list
Twain problems
Hi all!
Sorry for this rather lengthy post. It's a long preamble followed by a few
questions based on that.
Here's my situation: I am trying to write a specialized scanner utility for
my own needs, and I want to use the module twain to control my scanner. I
haven't used the twain module before, which is most certainly why I'm facing
problems. My problem is to interprete some of the information I get from the
scanner. The scanner, by the way, is an HP LaserJet 3020, which is a
multi-toy (printer/scanner/copyer), and I use Python 2.3 on Windows XP.
I set up communication with the scanner as follows (modulo a few ifs to take
care of unsuccessful connections). Here self is an instance of a class with
Tkinter.Tk as its base class.
self.SM = twain.SourceManager(self.winfo_id(),ProductName='foo')
self.SD = self.SM.OpenSource()
The TWAIN dialog pops up nicely, and I get two options: "hp LaserJet 3020
TWAIN 1.0 (32-32)" and "WIA-hp LaserJet 3020 1.0 (32-32)". The first choice
is HPs interface to the scanner, while the second seems to be a scanner
interface that comes with Windows.
One issue arises if I choose "WIA-hp LaserJet 3020 1.0 (32-32)" and then do
the following:
capVal=self.SD.GetCapability(twain.ICAP_CONTRAST)
After that capVal is
{'StepSize': 1,
'DefaultValue': 0,
'CurrentValue': 0,
'MaxValue': 1000,
'MinValue': 64536}
My educated guess is that 64536 should be interpreted as -1000, since 64536
is -1000 modulo 2**16. One problem is that the twain type is not specified.
So, perhaps I can find the twain type in some other way. The check
capDef=self.SD.GetCapabilityDefault(twain.ICAP_CONTRAST)
gives me capDef==( 7, 0.0 ). According to my introspection of the twain
module, the type 7 is twain.TWTY_FIX32. Googling around gives me the
impression that this corresponds to 32 bits of which the first 16 bits
correspond to the integer part, and the last 16 bits correspond to the
fraction part. I thought that the twain module would take care of sign
issues for me, but it does not seem to do so. OK, I can probably live with
that. In any case, I guess I'll have to.
OK, that's perhaps not so tough.
Another issue arises if I choose "hp LaserJet 3020 TWAIN 1.0 (32-32)" and
then do the following:
capVal=self.SD.GetCapability(twain.ICAP_XSCALING)
After that capVal is
{'StepSize': 429457408,
'DefaultValue': 1,
'CurrentValue': 1,
'MaxValue': 6,
'MinValue': 429457408}
Now I'm in trouble. The problem is to interprete capVal['StepSize'] and
capVal['MinValue']. Both should correspond to some small positive value.
Here the check
capDef=self.SD.GetCapabilityDefault(twain.ICAP_XSCALING)
gives me capDef==( 4, 100 ). More introspection says that type 4 is
twain.TWTY_UINT16. So, again googling around, and I find that this
corresponds to an unsigned 16bit integer, but that doesn't help me much
since 429457408 > 2**16. I also notice that capDef[1]==100, while
capVal['DefaultValue']==1, so there must be a scaling factor of 100
(percents, yes I know). But that doesn't change the fact that I'm completely
lost here.
Finally, here are my questions:
Can anyone enlighten me? From the above, I get the impression that the
dictionary returned by self.SD.GetCapability in these cases give me integer
approximations of the current and default values. Is that a correct
interpretation? How should I deal with 429457408 in the example above? Are
there other twain-type related issues that I haven't seen yet, that I should
be aware of? Is there some web-resource out there that answers my questions?
Am I simply missing some information that I might already have? At least I
haven't been able to find any enlightment in the documentation of the twain
module or in the TWAIN specification. It seems to me that I need to be very
careful with the type of the capabilities. How careful should I be?
Googling for things like TWTY_UINT16 typically results in what I interprete
as C or C++ code, which does not help me much. I'm less fluent in C or C++
than I am in Italian (I can order a beer and buy postcards or stamps, that's
more or less it).
I-cannot-order-a-beer-in-C-but-I-can-in-Python-ly yours
/Mikael Olofsson
Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE])
Linköpings universitet
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Re: aproximate a number
Michael Sparks wrote: > def approx(x): > return int(x+1.0) I doubt this is what the OP is looking for. >>> approx(3.2) 4 >>> approx(3.0) 4 Others have pointed to math.ceil, which is most likely what the OP wants. /Mikael Olofsson Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE]) Linköpings universitet --- E-Mail: [EMAIL PROTECTED] WWW: http://www.dtr.isy.liu.se/en/staff/mikael Phone: +46 - (0)13 - 28 1343 Telefax: +46 - (0)13 - 28 1339 --- Linköpings kammarkör: www.kammarkoren.com Vi söker tenorer och basar! -- http://mail.python.org/mailman/listinfo/python-list
Re: how to join two Dictionary together?
DENG wrote:
> dict1={...something...}
> dict2={...somethind else ..}
> dict1 + dict2
>
> that's does works ..:(, it's not like List...
> anyone can tell me how to get it?
I would do the following in most cases.
>>> dict1={'a':'A'}
>>> dict2={'b':'B'}
>>> dict3=dict1.copy()
>>> dict3
{'a': 'A'}
>>> dict3.update(dict2)
>>> dict3
{'a': 'A', 'b': 'B'}
HTH
/Mikael Olofsson
Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE])
Linköpings universitet
---
E-Mail: [EMAIL PROTECTED]
WWW: http://www.dtr.isy.liu.se/en/staff/mikael
Phone: +46 - (0)13 - 28 1343
Telefax: +46 - (0)13 - 28 1339
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Re: Optional algol syntax style
Sokolov Yura wrote: > I think, allowing to specify blocks with algol style (for-end, if-end, > etc) will allow to write easy php-like templates > and would attract new web developers to python (as php and ruby do). > It can be straight compilled into Python bytecode cause there is > one-to-one transformation. > [snip details] Standard answer to this kind of question: You can already do that in Python. It's spelled #end. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: working with VERY large 'float' and 'complex' types
Paul Rubin calculates exp(1000.0): > You could rearrange your formulas to not need such big numbers: > > x = 1000. > log10_z = x / math.log(10) > c,m = divmod(log10_z, 1.) > print 'z = %.5fE%d' % (10.**c, m) Nice approach. We should never forget that we do have mathematical skills beside the computers. But, shouldn't you switch c and m in the last row? /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter add_cascade option_add
Eric Brunel wrote in reply to Bob Greschke:
> I'm still not sure what your exact requirements are. Do you want to have
> a different font for the menu bar labels and the menu items and to set
> them via an option_add? If it is what you want, I don't think you can do
> it: the menus in the menu bar are just ordinary items for tk, and you
> can't control separately the different kind of menu items.
I guess he has the same problem as I have. See sample code:
from Tkinter import *
class App(Tk):
def __init__(self):
Tk.__init__(self)
self.option_add('*Menu.font', 'helvetica 24 bold')
self.menuBar=Menu(self)
self.fileMenu=Menu(self.menuBar,tearoff=0)
self.subMenu=Menu(self.fileMenu)
self.fileMenu.add_cascade(label='foo', menu=self.subMenu)
self.subMenu.add_command(label='bar',command=self.foo)
self.subMenu.add_command(label='baz',command=self.foo)
self.fileMenu.add_command(label='Quit',command=self.quit)
self.menuBar.add_cascade(label='File',menu=self.fileMenu)
self.config(menu=self.menuBar)
def foo(self):
pass
app=App()
app.mainloop()
What happens on my WinXP-box when I run this code is that the menu bar
still is displayed in the standard font, which seems to be Helvetica 8.
I.e. The text 'File' is still small, while everything else in the menus
is displayed in Helvetica 24 bold. Adding font=... to any of the
commands above does not change the appearance of 'File'. I have no
problems changing the appearance of any individual text in the menu
except for the mentioned 'File'. I can change the appearance of 'foo' in
the self.fileMenu.add_cascade row, but nothing happens to 'File' if I
try to specify a font in the self.menuBar.add_cascade row. Doesn't that
seem a bit peculiar?
But... The example you gave does not change the appearance of the menus
at all on my machine. I guess it was supposed to?
Is this simply a Windows-issue that cannot easily be solved? Or is it
possibly so that this just happens to be a problem on a few
ill-configured computers? Or am I possibly blind?
/MiO
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Re: plateform info.
Monu Agrawal wrote: > Hi I want to know whether the program is being run on windows or on > Xnix. Is there any variable or method which tells me that it's windows? Will this help? >>> import sys >>> sys.platform 'win32' There is also the platform module, that can give you a lot more information about the your platform. Try help(platform). /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Help w/ easy python problem
[EMAIL PROTECTED] wrote: > I am very much a beginner to python. I have been working on writing a > very simple program and cannot get it and was hoping someone could help > me out. Basically i need to write a code to print a sin curve running > down the page from top to bottom. The trick is I have to do this using > only 7-8 lines of code. Any ideas? This sounds like homework, and I think you should do that on your own. One hint, though: You could take a look at the standard module math. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Galois field
Roie Kerstein wrote: I am looking for a python package that deals with galois fields. Does anybody know where can I find it? Googling for python "finite field" reveals among other things the URLs http://www.hpcf.upr.edu/~humberto/software/fields/ http://www.csua.berkeley.edu/~emin/source_code/py_ecc/ I have not looked into those, but at least the first one seems to be in a very early state, since its version number is 0.1.1. The second one contains code for handling Reed-Solomon codes, which among other things includes arithmetic for finite fields. Good luck! /Mikael Olofsson Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE]) Linköpings universitet --- E-Mail: [EMAIL PROTECTED] WWW: http://www.dtr.isy.liu.se/en/staff/mikael Phone: +46 - (0)13 - 28 1343 Telefax: +46 - (0)13 - 28 1339 --- Linköpings kammarkör: www.kammarkoren.com Vi söker tenorer och basar! -- http://mail.python.org/mailman/listinfo/python-list
Re: Galois field
Roie Kerstein wrote: Thank you very much! However, I lack two important things in the packages introduced there: 1. There is only element arithmetic - no polynomials, in which I have need. 2. there is support only for fields of order 2^p, while I need fields of prime order. You still helped me, as before I searched for galois fields and found nothing, and search for finite fields yields more results. Off topic for the list, but possibly on topic for this thread: At our department we use Magma (http://magma.maths.usyd.edu.au/) for finite field arithmetic and error control codes. Magma has nothing to do with Python, instead it is a very mature tool of its own, mainly for descrete math. It knows what a permutation group is, it knows what GF(81) is, and much more. Check out the handbook (Magma on-line help) on the web site and be impressed. You will find finite fields under Basic Rings. Magma is not free, though, and licence fees vary depending on who is buying the licence, see the web site for details. Note that under certain circumstances you may be eligible for a free version. If you have access to Magma where you are, do consider using it. An example Magma session: banin:~> magma Magma V2.8-9 Fri Dec 3 2004 13:17:54 on banin[Seed = 735720219] Type ? for help. Type -D to quit. R:=PolynomialAlgebra(GF(3)); F:=GF(27); for el in F do for> print el, " ", MinimalPolynomial(el); for> end for; 1 x + 2 a x^3 + 2*x + 1 a^2 x^3 + x^2 + x + 2 a^3 x^3 + 2*x + 1 a^4 x^3 + x^2 + 2 a^5 x^3 + 2*x^2 + x + 1 a^6 x^3 + x^2 + x + 2 a^7 x^3 + x^2 + 2*x + 1 a^8 x^3 + 2*x^2 + 2*x + 2 a^9 x^3 + 2*x + 1 a^10 x^3 + x^2 + 2 a^11 x^3 + x^2 + 2*x + 1 a^12 x^3 + x^2 + 2 2 x + 1 a^14 x^3 + 2*x + 2 a^15 x^3 + 2*x^2 + x + 1 a^16 x^3 + 2*x + 2 a^17 x^3 + 2*x^2 + 1 a^18 x^3 + x^2 + x + 2 a^19 x^3 + 2*x^2 + x + 1 a^20 x^3 + 2*x^2 + 2*x + 2 a^21 x^3 + x^2 + 2*x + 1 a^22 x^3 + 2*x + 2 a^23 x^3 + 2*x^2 + 1 a^24 x^3 + 2*x^2 + 2*x + 2 a^25 x^3 + 2*x^2 + 1 0 x Regards /Mikael Olofsson Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE]) Linköpings universitet --- E-Mail: [EMAIL PROTECTED] WWW: http://www.dtr.isy.liu.se/en/staff/mikael Phone: +46 - (0)13 - 28 1343 Telefax: +46 - (0)13 - 28 1339 --- Linköpings kammarkör: www.kammarkoren.com Vi söker tenorer och basar! -- http://mail.python.org/mailman/listinfo/python-list
Re: Begniner Question
"Glen" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] if int(choice)==2: else: pass File "./Code.py", line 20 else: ^ IndentationError: expeted an indented block What am I doing wrong? As the error trace informs you, Python expexts an indented block. You need to put something between if and else, at least a pass. Regards -- /Mikael Olofsson Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE]) Linköpings universitet --- E-Mail: [EMAIL PROTECTED] WWW: http://www.dtr.isy.liu.se/en/staff/mikael Phone: +46 - (0)13 - 28 1343 Telefax: +46 - (0)13 - 28 1339 --- Linköpings kammarkör: www.kammarkoren.com Vi söker tenorer och basar! -- http://mail.python.org/mailman/listinfo/python-list
Re: Printable version of Python tutorila
<[EMAIL PROTECTED]> wrote: I liked the python tutorial ( http://www.python.org/doc/current/tut/tut.html ) very much. Now i want to print this tutorial. Where do i get a printable version of the document? http://www.python.org/doc/current/download.html Regards /Mikael Olofsson Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE]) Linköpings universitet --- E-Mail: [EMAIL PROTECTED] WWW: http://www.dtr.isy.liu.se/en/staff/mikael Phone: +46 - (0)13 - 28 1343 Telefax: +46 - (0)13 - 28 1339 --- Linköpings kammarkör: www.kammarkoren.com Vi söker tenorer och basar! -- http://mail.python.org/mailman/listinfo/python-list
Re: OT: excellent book on information theory
Terry Hancock wrote: "Tim Peters" <[EMAIL PROTECTED]> wrote: >> UK:Harry smiled vaguely back >> US:Harry smiled back vaguely Terry Hancock wrote: > I know you are pointing out the triviality of this, since > both US and UK English allow either placement -- but is it > really preferred style in the UK to put the adverb right > before the verb? In US English, the end of the clause > (or the beginning) is probably more common. I appreciate your desire to put the thread on (Python) topic, but as I see this discussion, it really has to do with respect for the author, but also respect for the reader. The UK version is most likely the way the author intended it to be. Then that is the way the text should be, regardless if it is preferred style or not, under the assumption that English is English is English. One question here is: Are US English and UK English different languages or not? If they are, a translation is in place. If they are not, the text should have been left as is. I guess the answer is: -Well, sort of... And that is probably the reason why opinions differ here, and also the reason why the American publisher has made some changes, but left most parts unchanged. A related important question is: Does the US version communicate the same thing (meaning aswell as feeling) to the American reader as the UK version communicates to the British reader? That should always be the objective for any translator. It also means that if the author in the UK version uses non-standard UK English, then the US version should use non-standard US English. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Why do this?
Matthew Warren wrote:
> I learned over the years to do things like the following, and I like
> doing it like this because of readability, something Python seems to
> focus on :-
>
> Print "There are "+number+" ways to skin a "+furryanimal
>
> But nowadays, I see things like this all over the place;
>
> print("There are %s ways to skin a %s" % (number, furryanimal))
>
> Now I understand there can be additional formatting benefits when
> dealing with numbers, decimal places etc.. But to me, for strings, the
> second case is much harder to read than the first.
>
I agree that the second alternative isn't too readable. It is also not
too maintainable. My version of the above is most often
print "There are %(number)s ways to skin a %(furryanimal)s." % vars()
Readable and maintainable.
/MiO
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Re: deleteing item from a copy of a list
timmy wrote: > i make a copy of a list, and delete an item from it and it deletes it > from the orginal as well, what the hell is going on?!?!?! > > #create the staff copy of the roster > Roster2 = [] > for ShiftLine in Roster: > #delete phone number from staff copy > Roster2.append(ShiftLine) > del Roster2[len(Roster2)-1][1] > > Roster2 should have nothing to do with Roster, right??? doing a print of > both lists confirms that the phone number has been removed from both > First of all, you could have said del Roster2[-1][1] since negative indices count backwards from the end of the list. This has nothing to do with your problem, though. Fredrik has already given you a correct, somewhat condensed, answer. Let me elaborate. I guess that Roster is a list of lists. Then actually, it is a list of references to lists (really a reference to a list of references to lists). Your for-loop makes Roster2 a shallow copy of Roster, i.e. Roster2 is a new list with references to the _same_ sublists as in Roster. So, Roster2[-1] references the same object as Roster[-1], not a copy of it. To get copies, you could change your .append-line to Roster2.append(ShiftLine[:]) which gives you shallow copies of the sublists. If there are mutables in the sublists, you may still get into trouble. In that case, maybe you should take a look at copy.deepcopy. HTH /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Running Python scripts under a different user
Laszlo Nagy wrote: > For Windows, you can use the 'runas.exe' program. But it requires a > password too. Or you can get a copy of the shareware program RunAsProfessional, which I use for my kids stupid games that necessarily has to be run by an admin. The price I paid was 10 Euro, which I still think was money well spent. IIRC you get a 30 days trial version for free. http://freedownloads.rbytes.net/cat/desktop/other3/runas-professional/ It does the same thing as RunAs, but you do not need to type the password every time you run your program. Instead the password is stored encrypted in the file you launch. I do not know what encryption is used, or how safe the encryption is. My needs are simply to make sure that my kids do not destroy anything by mistake. Sure, the stupid game may be designed to destroy, but that's another issue. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: cos: "Integer Required"?!?!?!?
moonman wrote: > print self.ACphi, type(self.ACphi) yields: > 19412557 > > value = XPLMGetDataf(self.ACphi); print value type(value ) yields: > -0.674469709396 > > print math.radians(XPLMGetDataf(self.ACphi)), > type(math.radians(XPLMGetDataf(self.ACphi))) yields: > > TypeError > : > an integer is required > > Am I totally missing something about 'math'. Does it really expect an > int? Not my Python: >>> math.radians(-0.674469709396) -0.011771717133929535 This all seems very confusing. Have you tried exactly the above? Do you perhaps have a module of your own called math, that Python might be importing? Or is your math not a module, but some other object that happens to have a method called radians, that expects an int? Or have you accidentally redefined math.radians? /MiO -- http://mail.python.org/mailman/listinfo/python-list
Changing behaviour of namespaces
Hi!
This is in Python 2.3.4 under WinXP.
I have a situation where I think changing the behaviour of a namespace
would be very nice. The goal is to be able to run a python file from
another in a separate namespace in such a way that a NameError is not
raised if a non-existing variable is used in the file. The file that I
want to run is taken out of context, and some needed variables may be
missing that are normally there when used in the intended context. OK!
When I run it out of context, I do not want the execution to stop
half-way through the file based on NameErrors, instead a predefined
dummy variable should be used. The question is: Can I achieve that?
Google didn't give me much, so I experimented a bit: First, I created a
dummy object, which is meant to be used when a variable is missing:
class dummyClass(object):
pass
dummyObject = dummyClass()
The actual dummy object is supposed to be a bit more complicated than
that. The next step was to subclass dict:
class forgivingDict(dict):
def __init__(self,*args,**kwargs):
dict.__init__(self,*args,**kwargs)
def __getitem__(self,key):
print 'Getting', key
try:
return dict.__getitem__(self,key)
except KeyError:
return dummyObject
def __setitem__(self,key,value):
print 'Setting', key, 'to', value
dict.__setitem__(self,key,value)
def __contains__(self,item):
return True
def __repr__(self):
return 'forgivingDict(%s)' % (dict.__repr__(self),)
Then I tried to execute a file using a forgivingDict() as namespace:
ns = forgivingDict()
execfile(filePath, ns)
A file containing the following passes perfectly OK:
a = 0
b = a
But a file containing the following produces a NameError:
b = a
The error traceback for the interested:
Traceback (most recent call last):
File "//charm/mikael/My
Documents/Programmering/Python/Tester/voidTest.py", line 130, in ?
execfile('test2.py', ns)
File "test2.py", line 1, in ?
b = a
NameError: name 'a' is not defined
Now, that is exactly what is to expect if ns is a dict(), but I was
hoping that b would have ended up as dummyObject when ns is a
forgivingDict(). One thing: Nothing is printed out when execfile-ing the
files, which means that the methods forgivingDict.__getitem__ and
forgivingDict.__setitem__ are never used. My guess was that the
execution done by execfile uses dict.__getitem__(ns, key) and
dict.__setitem__(ns,key,value) instead of ns[key] and ns[key]=value when
getting and setting variables. That is probably intentional from the
developers and done that way for a good reason.
Alternative test: I've tried to replace __builtin__.dict with my
forgivingDict, slightly modified to make sure that the inheritance still
works, which didn't change anything. So it seams that the execution done
by execfile does *not* use dict.__getitem__(ns, key) and
dict.__setitem__(ns,key,value) after all, but something else. Probably
the original dict is around somewhere else, and execfile uses the
corresponding methods of that.
My approach seems flawed. Any ideas? Can I somehow execute a complete
file even if there are non-existent variables used somewhere? A
try-except around the execfile statement is not an alternative, since
that stops the execution where the error occurs.
Should I perhaps read up on the compiler module? I mean: Using the
compiler module to analyze the content of the file, and based on that
updating my namespace before executing the file.
/MiO
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Re: Changing behaviour of namespaces - solved, I think
Peter Otten wrote:
> To feed an arbitrary mapping object to execfile() you need to upgrade to
> Python 2.4.
Thanks! As clear as possible. I will do that.
FYI: I think I managed to achieve what I want in Py2.3 using the
compiler module:
def getNamesFromAstNode(node,varSet):
if node.__class__ in (compiler.ast.Global,compiler.ast.Import):
varSet.union_update(node.names)
if node.__class__ in (compiler.ast.Name,):
varSet.add(node.name)
for subNode in node.getChildNodes():
getNamesFromAstNode(subNode,varSet)
# Get all variable names that are referenced in the file:
varSet = sets.Set()
mainNode = compiler.parseFile(filePath)
getNamesFromAstNode(mainNode,varSet)
# Define a namespace and update it:
ns = {}
for varName in varSet:
ns[varName] = dummyObject
# Execute the file without NameErrors:
execfile(filePath,ns)
Batteries included!
/MiO
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Re: Changing behaviour of namespaces - solved, I think
Peter Otten wrote: > Clearly more elegant than: > > print open(filename).read() > b = a > dummy = 42 names = [] while 1: > ... ns = dict((n, dummy) for n in names) > ... try: > ... execfile(filename, ns) > ... except NameError, e: > ... names.append(e[0][6:-16]) > ... else: > ... break > ... > names > ['a'] > That sure is nicer. My solution looks like shooting mosquitoes with an elephant rifle i comparison. Thanks. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: AN Intorduction to Tkinter
The following is the answer I gave on [EMAIL PROTECTED] Perhaps Fredrik can elaborate on the status of different versions of his excellent publication. Tanner Ruschman wrote about "An Introduction to Tkinter" by Fredrik Lundh: > > When I saw that it was written > > (actually, copyrighted) in 1999, I figured that a new(er) version of > > Tkinter had come out since then, changing how some of the code examples > > work. > > > > Does anybody know of a guide as comprehensive as this, but written for > > one of the more recent Tkinter modules? > You probably mean http://www.pythonware.com/library/tkinter/introduction/ which is copyrighted 1999. There is also http://effbot.org/tkinterbook/ which I think is the most recent version of it. It states that it is last updated in November 2005. HTH /Mikael Olofsson Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE]) Linköpings universitet --- E-Mail: [EMAIL PROTECTED] WWW: http://www.dtr.isy.liu.se/en/staff/mikael Phone: +46 - (0)13 - 28 1343 Telefax: +46 - (0)13 - 28 1339 --- Linköpings kammarkör: www.kammarkoren.com Vi söker tenorer och basar! -- http://mail.python.org/mailman/listinfo/python-list
Re: How can I make a class that can be converted into an int?
Matthew Wilson wrote:
> What are the internal methods that I need to define on any class so that
> this code can work?
>
> c = C("three")
>
> i = int(c) # i is 3
From Python Reference Manual, section 3.4.7 Emulating numeric types:
__complex__( self)
__int__( self)
__long__( self)
__float__( self)
Called to implement the built-in functions complex(), int(),
long(), and float(). Should return a value of the appropriate type.
/MiO
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Re: file backup in windows
k.i.n.g. wrote: > [snip code] > The above code was fine while printing, when I am trying to use this > (outlook_path) to use as source path it is giving file permission error > can you please clarify this Did you follow the link that Fredrik Lundh gave you? /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Tk.quit() now working!
Fredrik Lundh wrote: >>how do you run your Tkinter program ? al pacino wrote: > like? i was testing it in windows (interactive interpreter) What Fredrik probably means is: Did you by any chance start it from IDLE? In that case it will not work. It doesn't for me. The reason - I've been told - is that IDLE itself is a tkinter application. If you instead start it by simply double-clicking on its icon, as you would start anything else in Windows, it should work as expected. It does for me, on Win XP Pro. HTH /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Create dict from two lists
py wrote: > Thanks, itertools.izip and just zip work great. However, I should have > mentioned this, is that I need to keep the new dictionary sorted. Dictionaries aren't sorted. Period. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Soduku
Jonathan Gardner wrote: > How do you have a 16x16 grid for soduku? Are you using 16 digits? 0-F? > > The one I am using has 9 digits, 9 squares of 9 cells each, or 9x9 > cells. What alphabet you use is irrelevant. Sudokus has really nothing to do with numbers. You can use numbers, as well as letters, fruits, or car models. Numbers just happen to be nice to use as alphabet for fairly small sudokus. The hobby electronics magazine elektor at http://www.elektor-electronics.co.uk/ uses 0-F for their 16x16 sudokus. You can make sudokus of more or less any size. In the kids department at http://www.dailysudoku.co.uk you can find 4x4 and 6x6 grids. Apart from those and the standard 9x9, I have also seen 12x12, 16x16 and 25x25. You could make them 8x8 or 99x99 if you wish. Those numbers should be non-primes, though, since the pattern of sub-blocks breaks if the numbers are primes. Perhaps I should mention the three-dimensional one (9x9x9) that someone showed me at work. That particular one was a bore, since it contained too much patterns. Or the two orthogonal ones, where you have two 9x9 sudokus in one with interrelations... Finally, dailysudoku also has what they call squiggly sudokus, e.g. http://www.dailysudoku.co.uk/sudoku/squiggly/archive.shtml?year=2006&month=02&day=15 By the way, if I'm not completely mistaken, there are only two non-equivalent solutions to the 4x4 grid. The equivalence relations taken into account are then the following: Permutations of the alphabet. Interchanging interchangeable rows or columns. Transpose - as in matrix transpose - of the whole grid. Enough off-topic for now /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter Checkboxes
D wrote: > Ok, I'm sure this is something extremely simple that I'm missing, > but..how do I set a variable in a Tkinter Checkbox? i.e. I have a > variable "test" - if the checkbox is selected, I want to set test=1, > otherwise 0. Thanks! > http://www.pythonware.com/library/tkinter/introduction/x3897-patterns.htm /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Little tool - but very big size... :-(
Durumdara wrote: > But it have very big size: 11 MB... :-( > > The dist directory: > [snip relatively small files] > 2005.09.28. 12:41 1 867 776 python24.dll > [snip relatively small files] > 2006.01.10. 19:09 4 943 872 wxmsw26uh_vc.dll > [snip relatively small files] > 20 file11 485 758 byte > > I need to have more compressed result. Can I compress dll-s, pyd-s with > Py2Exe ? > Can I decrease the total size with something ? I've snipped out the relatively small files above. Yes, true, some of them consume about 0.5MB each. It seems to me that your choice of GUI framework is a major cost here. I have never used wxpython. Instead my GUIs are based on tkinter. What I typically end up with is roughly 7MB. My last example ended up in 7.5MB. Zipping the whole thing reduces that to 2.6MB. Is it completly out of the question to have a compressed version of the tool on your memory stick, and to decompress it on the examined computer before actually running the tool? /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Writing an applilcation that can easily adapt to any language
Chance Ginger wrote:
> I am rather new at Python so I want to get it right. What I am doing
> is writing a rather large application with plenty of places that
> strings will be used. Most of the strings involve statements of
> one kind or another.
>
> I would like to make it easy for the support people to port the
> application from one language to another, German, Spanish, etc.
> Rather than make them search all over for the strings to replace
> is there a library that I can use to make this all easier? I
> keep thinking of resources in Java, as an example. Is there
> anything like it in Python?
Brono's suggestion is most certainly very good. If you are looking for
something more light-weight, you might enjoy my module language that I
include below. The idea is to have everything language-specific in one
module, that is imported everywhere it is needed in my application. Consider
import language
fileText = language.texts['file']
After this, fileText is either 'File' or 'Arkiv' depending on if
language.lang is 'en' or 'sv'. The docstrings should be enough
documentation to use the module. perhaps you might want to split the
module up into two modules, one containing the class, and one containing
the texts.
/MiO
And here is the module:
# -*- coding: cp1252 -*-
"""Module language:
The most important object made available here is the following:
handleLanguage
A class that handles information in different languages. See the
doc-string of this class for more information.
texts
A dictionary containing objects of the class handleLanguage.
lang
A string representing chosen language.
availableLanguages
A list of strings representing available languages. The first
item is the default fallback language if lang fails.
"""
lang='en'
availableLanguages=[lang]
class handleLanguage(dict):
"""class handleLanguage:
A class that handles information in different languages as strings.
This class is instantiated as follows:
foo=handleLanguage(sv='blah',en='blahblah')
After that we have foo['sv']=='blah' and foo['en']=='blahblah'.
Also, the languages 'sv' and 'en' will have been appended to the
module level list availableLanguages if they were not in that list
before.
Now let foo be any instance of this class. The real funtionality of
this class is that str(foo) depends on the module variables lang and
availableLanguages. More precicely str(foo)==foo[x] where x chosen
according to the following.
if lang in foo: x=lang
elif availableLanguages[0] in foo: x=availableLanguages[0]
elif 'en' in foo: x='en'
else: x=foo.keys()[0].
If none of this works, then we have str(foo)=='??', which only
happens if foo does not contain any language.
"""
def __init__(self,**kwargs):
dict.__init__(self,**kwargs)
for key in kwargs:
if key not in availableLanguages:
availableLanguages.append(key)
def __str__(self):
try:
return self[lang]
except KeyError:
if availableLangages[0] in self:
return self[availableLangages[0]]
elif 'en' in self:
return self['en']
elif self:
return self[self.keys()[0]]
else:
return '??'
def __add__(self,other):
if not isinstance(other,dict):
foo,other=self.__coerce__(other)
new=handleLanguage(**dict(other))
new.update(self)
for key in self:
if key in other:
new[key]=self[key]+other[key]
return new
def __radd__(self,other):
if not isinstance(other,dict):
foo,other=self.__coerce__(other)
new=handleLanguage(**dict(other))
new.update(self)
for key in self:
if key in other:
new[key]=other[key]+self[key]
return new
def __coerce__(self,other):
new=handleLanguage()
for key in self:
new[key]=str(other)
return self,new
texts={
# Common texts
'appName':handleLanguage(
sv='Uppgiftshanteraren',
en='TaskManager',
),
'foo':handleLanguage(
sv='foo',
en='foo',
),
# File menu
'file':handleLanguage(
sv='Arkiv',
en='File',
),
'help':handleLanguage(
sv='Hjälp',
en='Help',
),
'open':handleLanguage(
sv='Öppna',
en='Open',
),
}
if __name__=="__main__":
keys=texts.keys()
keys.sort()
for lang in availableLanguages:
print lang
for key in keys:
print ' ',key+':',texts[key]
print
print 'Done'
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Re: a re problem
cheng wrote:
>>>p.sub('','%s') % "a\nbc"
>>>
>>>
>'a\nbc'
>
>is it anyone got some idea why it happen?
>
Make that
p.sub('','%s' % "a\nbc")
Regards
/Mikael Olofsson
Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE])
Linköpings universitet
---
E-Mail: [EMAIL PROTECTED]
WWW: http://www.dtr.isy.liu.se/en/staff/mikael
Phone: +46 - (0)13 - 28 1343
Telefax: +46 - (0)13 - 28 1339
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Re: prime number
lostinpython wrote: > What civil engineers need with all this programming is beyond me. We > have to learn another language to program our CADD software, which I > find much easier than this. According to my experience, almost every engineer - civil or not - uses programming at least occationally. So every engineering education program should involve at least some programming. /Mikael Olofsson Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE]) Linköpings universitet --- E-Mail: [EMAIL PROTECTED] WWW: http://www.dtr.isy.liu.se/en/staff/mikael Phone: +46 - (0)13 - 28 1343 Telefax: +46 - (0)13 - 28 1339 --- Linköpings kammarkör: www.kammarkoren.com Vi söker tenorer och basar! -- http://mail.python.org/mailman/listinfo/python-list
Re: c[:]()
Warren Stringer wrote: > I want to call every object in a tupple, like so: > [snip examples] > Why? Because I want to make Python calls from a cell phone. > Every keystroke is precious; even list comprehension is too much. If you are going to do this just a few times in your program, I cannot help. But: If you want to do it several times, perhaps you have space for an initial class definition, like so: class CallableList(list): def __call__(self,*args,**kwargs): return [f(*args,**kwargs) for f in self] def a(): return 'a called' def b(): return 'b called' c = CallableList([a,b])() You might want to trim the class to fit your needs, perhaps use a shorter name, and perhaps you don't need to handle arguments. Can the class be placed in a module, so that it only needs to be typed once in your application? /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Combinatorial of elements in Python?
Sebastian Bassi wrote:
> I have 2 (or more) groups of elements, and I want to get all possible
> unique combinations from all of them. Is there a build-in method to do
> it?
>
> ADictionary={"one":["A","B","C","D"],"two":["H","I"]}
>
> I want to have all possible combinations from "one" and "two", that is:
> [snip]
Not at all complicated. My solution:
>>> A={'one':['A','B','C','D'],'two':['H','I']}
>>> [x+y for x in A['one'] for y in A['two']]
['AH', 'AI', 'BH', 'BI', 'CH', 'CI', 'DH', 'DI']
HTH
/MiO
--
/Mikael Olofsson
Universitetslektor (Senior Lecturer [BrE], Associate Professor [AmE])
Linköpings universitet
---
E-Mail: [EMAIL PROTECTED]
WWW: http://www.dtr.isy.liu.se/en/staff/mikael
Phone: +46 - (0)13 - 28 1343
Telefax: +46 - (0)13 - 28 1339
---
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Re: Combinatorial of elements in Python?
Sebastian Bassi wrote:
> Hello, could you do it for an indefinite number of elements? You did
> it for a fixed (2) number of elements. I wonder if this could be done
> for all members in a dictionary.
What is unclear here is in what order the keys should be visited. The
following assumes that the keys should be considered in alphanumeric order.
>>> def combine(d):
if not d:
return []
elif len(d)==1:
return d.values()[0]
else:
keys = d.keys()
keys.sort()
leftKeys = keys[0:len(keys)//2]
rightKeys = keys[len(keys)//2:]
leftDict = dict((key,d[key]) for key in leftKeys)
rightDict = dict((key,d[key]) for key in rightKeys)
return [x+y for x in combine(leftDict) for y in combine(rightDict)]
>>>
A={'field1':['a','A'],'field2':['b','B'],'field3':['c','C'],'field4':['d','D']}
>>> combine(A)
['abcd', 'abcD', 'abCd', 'abCD', 'aBcd', 'aBcD', 'aBCd', 'aBCD', 'Abcd',
'AbcD', 'AbCd', 'AbCD', 'ABcd', 'ABcD', 'ABCd', 'ABCD']
HTH again
/MiO
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Re: Combinatorial of elements in Python?
Sebastian Bassi wrote:
> On 8/15/07, Mikael Olofsson <[EMAIL PROTECTED]> wrote:
>
>> What is unclear here is in what order the keys should be visited. The
>> following assumes that the keys should be considered in alphanumeric order.
>>
>
> Yes, my fault. The orden should be given by a string, like:
>
> DCDBA
> Using this dictionay.
> A={'A':['1','2'],'B':['4','5'],'C':['6','7','8'],'D':['9']}
>
> Should return:
>
> '96941'
> '97941'
> '97942'
> '96942'
> '98941'
> '98942'
> '96951'
> '97951'
> '97952'
> '96952'
> '98951'
> '98952'
OK, seems like you need to add a second argument to the function
specifying this order. I leave that to you.
/MiO
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Re: beginner, idiomatic python
bambam wrote: > > In this case it doesn't matter - my lists don't contain > duplicate elements this time - but I have worked with lists in > money market and in inventory, and finding the intersection > and difference for matching off and netting out are standard > operations. I would use a list comprehension for that case: A = ['a','b','c','a','c','d'] U = ['a','b','e'] B = [x for x in A if x in U] The result would be B==['a','b','a'] /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Tell me the truth
[EMAIL PROTECTED] wrote: > If I take into account the fact that 'True' and 'False' are singletons > (guaranteed ?) : > (not not x) is bool(x) # should be always True. > [snip code and results of code] > Consider the following: >>> def ok1(x): return (not not x) is bool(x) >>> def ok2(x): return (not not x) is bool(x) is True >>> def ok3(x): return ok1(x) is True >>> def ok4(x): return ((not not x) is bool(x)) is True >>> def ok5(x): return ((not not x) is bool(x)) and (bool(x) is True) >>> for x in [False, True]: print x,ok1(x), ok2(x), ok3(x), ok4(x), ok5(x) False True False True True False True True True True True True Note that ok2(x) and ok5(x) exhibit the same behaviour. HTH /MiO -- http://mail.python.org/mailman/listinfo/python-list
Communicating with a DLL under Linux
I am interested in peoples experience with communicating with DLLs under Linux. Situation: I'm an electrical engineer that finds pleasure in using my soldering iron from time to time. I also find programming, preferably in Python, entertaining. I wouldn't call myself a programmer, though. Now, I may have found a hobby project that could give me the pleasure from both those worlds. There's this USB development gadget for sale in my favourite electronics store, and I sure would like to have something like that connected to my lab computer (a fairly new budget computer running Kubuntu 6.06). The gadget costs about 50 Euros. It's not a lot of money, but I would not like to buy the thing if there is a substancial risk that I will not be able to make it work on that computer. From what I've read on the box, it assumes Windows (a number of versions), it includes a DLL to communicate with it, and example code in VB (iirc). For the interested, here's the gadget: http://www.elfa.se/elfa-bin/dyndok.pl?lang=en&vat=0&dok=9001.htm I have been looking at ctypes, and from what I read, I should be able to communicate with a DLL by using ctypes. It even sounds fairly easy, as long as I know what the DLL is supposed to do. I expect there to be some kind of manual for the DLL included in the box. Are DLLs universal, or are there different DLLs for Windows and Linux (I'm not a programmer, remember)? If the vendor claims that the DLL is for Windows, is it reasonable to assume that it can be made to work under Linux, from Python, that is? Or is this perhaps completely out of the question? So, who is willing share their experiences? Share advice? Is this as easy as it sounds to me? Any pitfalls around? Regards /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Communicating with a DLL under Linux
Thanks for all the responces, both on and off list. So, I should forget about the DLL, and if I intend to connect the thing to a Linux computer, I'll have to develop the code myself for communicating with it over USB. Fair enough. I might even try that. I've done some surfing since yesterday. Why do I always do that after asking stupid questions in public? It turns out that a Nicolas Sutre has already ported the thing to Linux: http://linuxk8055.free.fr/ Velleman links to his solution from their product page http://www.velleman.be/ot/en/product/view/?id=351346 which might mean something. Nicolas solution is only 250 lines of C code. It #includes a usb.h, so I guess a lot of its functionality is hidden there. It seems structured enough, so I might be able to find some inspiration there. I guess I have some reading to do before I can decide if I shall do this. Anyway, thanks once again for the responces. Not completely in dispair... /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: about __str__
Bruno Desthuilliers wrote: > def __str__(self): > return "<%s:%s>" % (self.commiterID_, self.commits_) I would write that in the following way: def __str__(self): return "<%(commiterID_)s:%(commits_)s>" % self.__dict__ More explicit IMHO. And easier to maintain, especially if the string would contain several insertions. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Yield
Mathias Panzenboeck wrote: > def primes(): > yield 1 > yield 2 > [snip rest of code] > Hmm... 1 is not a prime. See for instance http://en.wikipedia.org/wiki/Prime_number The definition given there is "In mathematics , a *prime number* (or a *prime*) is a natural number that has exactly two (distinct) natural number divisors ." The important part of the statement is "exactly two...divisors", which rules out the number 1. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Yield
I wrote: > The definition given there is "In mathematics , a > *prime number* (or a *prime*) is a natural number > that has exactly two (distinct) natural number > divisors ." The important part of the statement is > "exactly two...divisors", which rules out the number 1. Or should I say: Thunderbird made me write:... Those freakin and was not visible before I posted the thing. &%#&%# /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Please take me off the list
Daniel kavic wrote: > Sorry to waste email space , but I wish to be off this list because I have > tried python and it is too difficult for me. > That's sad. Go to http://mail.python.org/mailman/listinfo/python-list and follow instructions. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Convert to binary and convert back to strings
Neil Cerutti wrote: > Woah! You better quadruple it instead. > How about Double Pig Latin? > No, wait! Use the feared UDPLUD code. > You go Ubbi Dubbi to Pig Latin, and then Ubbi Dubbi again. > Let's see here... Ubububythubububonubpubay > That's what I call ubububeautubububifubububulbubay. That looks slightly like the toy language that Swedish kids refer to as the robbers language: You double each consonant, and place an o between each such double consonant. So, applying that to Python, you would get popytothohonon. Actually, one of the largest Swedish telecom companies has used this toy language in one of their commercials. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie question(file-delete trailing comma)
kavitha thankaian wrote:
> i get an error when i try to delete in file and rename it as out
> file,,the error says
> "permission denied".
Perhaps you should give us both the exact code you are running and the
complete traceback of the error. That could make things easier. There
can be numerous reasons for "permission denied".
> actually i need something like following:
>
> in_file = open('in.txt','w')
> for line in in_file:
> line.strip().strip(',')
>
> but when i run the above code,i get an error"bad file descriptor"
Of course you do! You are opening the file for writing, but your code
attempts to read the file. Probably, you think that the code would
change the lines in the file itself, which it does not, even if it would
be possible to read from a file opened for writing.
What's wrong with the code that Mohammad posted? Note that you might
need to close out_file in his code.
/MiO
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Re: newbie question(file-delete trailing comma)
kavitha thankaian wrote:
> my script writes a dictionary to a file.but i need only the values
> from the dictionary which should be sepearted by a comma,,,so i did as
> following:
> [snip code that generates the incorrect original file]
> when i execute the above code,my test.txt file has the following:
> a,b,c,d,
> now i need to delete the comma at the end,,,this is my problem,,,
This is the first time you mention that you have control over the
generation of the original file. Then I suggest that you fix the problem
before generating the file. For instance, consider the following
interactive session.
>>> some={1:'a',2:7,3:'c',4:'d'}
>>> some
{1: 'a', 2: 7, 3: 'c', 4: 'd'}
>>> some.values()
['a', 7, 'c', 'd']
>>> [str(x) for x in some.values()]
['a', '7', 'c', 'd']
>>> ','.join([str(x) for x in some.values()])
'a,7,c,d'
Then write that to your file instead.
/MiO
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Re: Sine Wave Curve Fit Question
Helmut Jarausch wrote: > Your model is A*sin(omega*t+alpha) where A and alpha are sought. > Let T=(t_1,...,t_N)' and Y=(y_1,..,y_N)' your measurements (t_i,y_i) > ( ' denotes transposition ) > > First, A*sin(omega*t+alpha) = > A*cos(alpha)*sin(omega*t) + A*sin(alpha)*cos(omega*t) = > B*sin(omega*t) + D*cos(omega*t) > > by setting B=A*cos(alpha) and D=A*sin(alpha) > > Once, you have B and D, tan(alpha)= D/B A=sqrt(B^2+D^2) This is all very true, but the equation tan(alpha)=D/B may fool you. This may lead you to believe that alpha=arctan(D/B) is a solution, which is not always the case. The point (B,D) may be in any of the four quadrants of the plane. Assuming B!=0, the solutions to this equation fall into the two classes alpha = arctan(D/B) + 2*k*pi and alpha = arctan(D/B) + (2*k+1)*pi, where k is an integer. The sign of B tells you which class gives you the solution. If B is positive, the solutions are those in the first class. If B is negative, the solutions are instead those in the second class. Whithin the correct class, you may of course choose any alternative. Then we have the case B=0. Then the sign of D determines alpha. If D is positive, we have alpha=pi/2, and if D is negative, we have alpha=-pi/2. Last if both B and D are zero, any alpha will do. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: confused about __str__ vs. __repr__
Diez B. Roggisch wrote: Yep. And it's easy enough if you don't care about them being different.. def __repr__(self): return str(self) If I ever wanted __str__ and __repr__ to return the same thing, I would make them equal: def __str__(self): return 'whatever you want' __repr__ = __str__ That makes it more obvious to me what's going on. As a bonus, it saves one method call for every repr call. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: What happened to NASA at Python? :(
s...@pobox.com wrote: In fact, graphics were added for several organizations. I believe they will be chosen randomly. NASA is still there. In that case, they must be using the random number generator from Dilbert. You know, the one that said 9, 9, 9, 9,... I, at least, get the same parking lot graphics every time I reload the page. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Man Bites Python
I don't think the guy in question finds it that funny. Roy Hyunjin Han wrote: Hahaha! On Thu, Apr 16, 2009 at 10:27 AM, Aahz wrote: http://news.yahoo.com/s/nm/20090415/od_nm/us_python_odd_1/print -- Aahz (a...@pythoncraft.com) <*> http://www.pythoncraft.com/ Why is this newsgroup different from all other newsgroups? -- http://mail.python.org/mailman/listinfo/python-list
Decorating methods - where do my arguments go?
Hi all! I have long tried to avoid decorators, but now I find myself in a situation where I think they can help. I seem to be able to decorate functions, but I fail miserably when trying to decorate methods. The information I have been able to find on-line focuses on decorating functions, and do not mention any special problem regarding methods. Consider the following example. I start by defining a simple decorator: >>> class test_decorator(object): ... def __init__(self,func): ... self._func = func ... def __call__(self, *args): ... print 'Decorator:', args ... self._func(*args) Then I decorate a function: >>> @test_decorator ... def func(*args): ... print 'Function: ', args Let's try that: >>> func(1,2,3) Decorator: (1, 2, 3) Function: (1, 2, 3) OK! That was what I expected. Let's decorate a method: >>> class cls(object): ... @test_decorator ... def meth(self,*args): ... print 'Method: ', args Then try that: >>> cls().meth(1,2,3) Decorator: (1, 2, 3) Method:(2, 3) Oops! That's weird. I had expected - or at least wanted - the same result as for the function above. Where did the first argument go? If it was sent to the original method meth as the real first argument (self), then why did I not get an exception? More importantly: How do I write a decorator that does not drop arguments? I guess it all has to do with the fact that the returned callable isn't a method of cls. Is it possible to write a decorator that returns a callable that is a method of cls, when used on methods in cls? /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Decorating methods - where do my arguments go?
Peter Otten wrote: You have to turn your decorator into a descriptor by providing a __get__() method. A primitive example: class test_decorator(object): def __init__(self,func): self._func = func def __call__(self, *args): print 'Decorator:', args self._func(self.inst, *args) def __get__(self, inst, cls): self.inst = inst return self Thanks! Works perfectly for methods, as far as I can see. That's perfectly OK, since that is what I was asking for. What I failed to include in my original post is that I intend to use the decorator for functions as well. The above fails for functions on the second row of __call__ with AttributeError: 'test_decorator' object has no attribute 'inst' It seems to me like __get__ is not called when decorating a function. I guess there's no reasonable value for inst in that case. It might be the function itself, but it doesn't make sense to call the function with itself as its first argument, when it isn't supposed to be called that way. George Sakkis decorator function solution seems to work equally well for functions and methods. However, I prefer the cleaner encapsulation given by a class. Based on those observations, I think I will use the following approach: >>> class test_decorator(object): ... _inst = None ... def __init__(self,func): ... self._func = func ... def __call__(self, *args): ... print 'Decorator:', args ... if self._inst is None: ... print 'We seem to be decorating a function.' ... self._func(*args) ... else: ... print 'We seem to be decorating a method.' ... self._func(self._inst,*args) ... def __get__(self, inst, cls): ... self._inst = inst ... return self ... >>> >>> @test_decorator ... def func(*args): ... print 'Function: ', args ... >>> >>> func(1,2,3) Decorator: (1, 2, 3) We seem to be decorating a function. Function: (1, 2, 3) >>> >>> class cls(object): ... @test_decorator3 ... def meth(self,*args): ... print 'Method: ', args ... >>> >>> cls().meth(1,2,3) Decorator: (1, 2, 3) We seem to be decorating a method. Method:(1, 2, 3) If there are any drawbacks with this approach that I fail to see, please enlighten me. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Decorating methods - where do my arguments go?
George Sakkis wrote: Yes, just return an actual function from the decorator instead of a callable object: def test_decorator2(func): def wrapper(*args): print 'Decorator2:', args func(*args) return wrapper class cls(object): @test_decorator def meth(self,*args): print 'Method: ', args @test_decorator2 def meth2(self,*args): print 'Method2: ', args Thanks! This has the merit over Peter's solution that it seems to work for both functions and methods. However, as you can see from my answer to Peter, I think I will go for a class based approach anyway. Still, your answer helped me grasping the concepts. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Decorating methods - where do my arguments go?
Duncan Booth wrote: The __get__ method should be returning a new object, NOT modifying the state of the decorator. As written it will break badly and unexpectedly in a variety of situations: [snip good examples of things going bad] Ouch! So, does that mean that George's solution based on a function is the way to go, or does that mean that my __call__ should analyze the passed callable? /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Decorating methods - where do my arguments go?
Peter Otten wrote: I usually use decorator functions, but I think the following should work, too: class deco(object): def __init__(self, func): self._func = func def __call__(self, *args): print "Decorator:", args self._func(*args) def __get__(self, *args): return deco(self._func.__get__(*args)) This looks like a winner to me. It is elegant, works for functions as well as for methods, and does not mess with the internals of the decorator which avoids the problems that Duncan pointed out. Thanks Peter, and thanks everyone else that chimed in and contributed. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Decorating methods - where do my arguments go?
Michele Simionato wrote: > Still it turns something which is a function into an object and > you lose the docstring and the signature. pydoc will not be too > happy with this approach. Duncan Booth wrote: I don't know why Mikael wants to use a class rather than a function but if he wants to save state between calls this isn't going to help. I've never used decorators before, and that's the main reason for my confusion. I have found myself in a situation where I think that decorators is the way to go. So I tried to find information about how to write them the usual way: Googling and browsing documentation. I found examples using both functions and classes, but not much explanation of what's going on, especially not in the class case. I didn't find any arguments for favouring any of those alternatives. Actually, most examples I found did not even include the definition of the actual decorator or any information about where they might come from, only the @-row. Based on the above observations, I assumed that both alternatives were equally possible. The first answers I got here also led me to believe that that was the case. My understanding is that in most cases, you can use a callable object instead of a function with little or no practical difference, except the syntax of its definition. In my eyes, a class definition looks nicer and is more readable than a nested function. Therefore, I tend to define a class with a __call__ method and helper methods instead of nested functions, if I find the need. Practicality beats purity, and it seem like using a class for decoration is a lot more hassle than using a function. I fold. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: passing *args "recursively"
Guillermo wrote: This must be very basic, but how'd you pass the same *args several levels deep? def func2(*args) print args # ((1, 2, 3),) # i want this to output (1, 2, 3) as func1! # there must be some better way than args[0]? def func1(*args): print args # (1, 2, 3) func2(args) func1(1,2,3) func2(*args) Thats all. See http://docs.python.org/tut/node6.html#SECTION00674 /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: passing *args "recursively"
Guillermo wrote: This must be very basic, but how'd you pass the same *args several levels deep? def func2(*args) print args # ((1, 2, 3),) # i want this to output (1, 2, 3) as func1! # there must be some better way than args[0]? def func1(*args): print args # (1, 2, 3) func2(args) func1(1,2,3) Me, myself and I wrote: func2(*args) Thats all. See http://docs.python.org/tut/node6.html#SECTION00674 That was a bit unclear. You should use func2(*args) when you call the function. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Rounding a number to nearest even
[EMAIL PROTECTED] commented about rounding towards even numbers from mid-way between integers as opposed to for instance always rounding up in those cases: > Strange request though, why do you need it that way, because 2.5 is > CLOSER to 3 than to 2... That's exactly how I was taught to do rounding in what-ever low-level class it was. The idea is to avoid a bias, which assumes that the original values are already quantized. Assume that we have values quantized to one decimal only, and assume that all values of this decimal are equally likely. Also assume that the integer part of our numbers are equally likely to be even or odd. Then the average rounding error when rounding to integers will be 0.05 if you always round up when the decimal is 5. If you round towards an even number instead when the decimal is 5, then you will round up half of those times, and round down the other half, and the average rounding error will be 0. That's the idea. Of course you could argue that it would be even more fair to make the choice based on the tossing of a fair coin. Note that if you do not have quantized values and assuming that the fraction part is evenly distributed between 0 and 1, than this whole argument is moot. The probability of getting exactly 0.5 is zero in that case, just as the probability of getting any other specified number is zero. That said, measurements are in practice always quantized, and rounding towards an even number when mid-way between avoids an average error of half the original precision. As a side-note: The the smallest coin in Swedish currency SEK is 0.50, but prices in stores are given with two decimals, i.e. with precision 0.01. But what if your goods add up to 12.34? The standard in Swedish stores, after adding the prices of your goods, is to round the number to the nearest whole or half SEK, which means that decimals 25 and 75 are mid-way between. In those cases the rounding is usually done to the nearest whole SEK, which is based on precicely the above reasoning. If they did not do that, I could argue that they are stealing on average 0.005 SEK from me every time I go to the store. Well... I could live with that, since 0.005 SEK is a ridiculously small amount, and even if I make thousands of such transactions per year, it still sums up to a neglectable amount. Another side-note: My 12-year old son is now being taught to always round up from mid-way between. Yet another example of the degradation of maths in schools. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: Negative integers
Derek Martin wrote: Zero is a problem, no matter how you slice it. I definitely agree with that. Depends on the the real problem that is behind the OP:s question. Zero can be considered positive or negative (mathematically, 0 = -0). I've read quite a few articles written by mathematicians and mathematically oriented engineers, and my impression is that most of them, and therefore me included, use those words with the following meaning: Positive: >0 Negative: <0 When zero is to be included, the following terms are used: Non-negative: >=0 Non-positive: <=0 Using this convention, zero is neither positive nor negative. Wikipedia seems to agree with that: http://en.wikipedia.org/wiki/Positive_number /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: implementation of "complex" type
Russ wrote: x = complex(4) y = x y *= 2 print x, y > > (4+0j) (8+0j) > > But when I tried the same thing with my own class in place of > "complex" above, I found that both x and y were doubled. I'd like to > make my class behave like the "complex" class. Can someone tell me the > trick? Also, where can I find the code for for the "complex" class? I > hope it's written in Python! Thanks. Have your __imul__ and such return new objects, and not perform in-place modification if you do not want x and y to refer to the same object after y*=2. /MiO -- http://mail.python.org/mailman/listinfo/python-list
Re: accesibility of the namespace
Petr Jakes wrote:
> Ops. My keyboard (fingers) was faster than my mind :(
> So
> There is more than one "run-time changed variable" in the dictionary
> and not all strings in the dictionary are formatted using % operator.
> Example:
> lcd={
> 2:{2:(("Enter you choice"),("Your kredit= %3d" % (kredit)))},
> 4:{2:(("Your choice: %2s" % (keyboard)),("%-20s" % (actKeyboard)))}}
>
> I do not know which variable(s) to use for the % operator in the time
> of the call of the value (% formatted string) from the dictionary.
>
> This is also the reason why the variable names are stored in the
> dictionary with the strings.
>
> Any other suggestions?
So, use something like
>>> lcd={
2:{2:("Enter you choice","Your kredit= %(kredit)3d")},
4:{2:("Your choice: %(keyboard)2s" ,"%(actKeyboard)-20s")}}
>>> kredit = 7
>>> keyboard = 'aa'
>>> actKeyboard = 7654
>>> lcd[2][2][-1] % vars()
'Your kredit= 7'
>>> lcd[2][2][0] % vars()
'Enter you choice'
>>> lcd[4][2][0] % vars()
'Your choice: aa'
>>> lcd[4][2][1] % vars()
'7654'
>>>
HTH
/MiO
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