ANN: PAMIE web dev testing with Internet Explorer (2 New ShowMeDo.com Videos)
Summary: Robert Marchetti has created two videos showing you how to use his PAMIE tool to interactively drive Internet Explorer for web development and testing: http://showmedo.com/videos/series?name=pythonMarchettiPamieSeries Detail: The first PAMIE video covers driving IE interactively (querying Google, check the html src, clicking a button, visiting the Python homepage as a result). The second video shows you how to configure PAMIE with an XML file to automatically form-fill a web page for testing. This video also shows nice usage of the ElementTree module. The videos are 9 minutes and 11 minutes respectively and should play on all platforms. About ShowMeDo.com: Free videos (we call them ShowMeDos) showing you how to do things. The videos are made by us and our users, for everyone. Over half of our content is for Python. We'd love to have more contributions - would you share what you know? The founders, Ian Ozsvald, Kyran Dale -- ian at showmedo.com http://www.showmedo.com -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: Python to use a non open source bug tracker?
Ben Finney wrote: David Goodger [EMAIL PROTECTED] writes: Look at the results again. Jira and RoundUp tied for functionality, but Jira has a hosting/admin offer behind it. That's huge. But rather than declaring Jira the outright winner, which they could have done, the committee has allowed the community to decide the matter. If enough admins come forward, RoundUp will win. I read that as a big push for written in Python. I prefer to read it as a big push for not dependent on non-free tools. And I'd prefer it if you'd drop this subject. So, if you have nothing new to say, kindly leave it. You have made your opinion known, as you are fully entitled to do. Frankly I am getting less interested in your opinion with each new post. You appear to be prepared to go to any length short of providing effort to support the open source tracker. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
Re: dictionary of list from a file
[EMAIL PROTECTED] wrote:
d = {}
for line in [l[:-1] for l in file('test.txt', 'rU') if len(l)1]:
k,v = line.split()
d.setdefault(k,[]).append(v)
Try that with a test.txt where the last line has no newline.
Peter
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Steve Holden wrote: You appear to be prepared to go to any length short of providing effort to support the open source tracker. http://www.userland.com/whatIsStopEnergy /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Terry Reedy wrote: Ben Finney [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] The whole point of moving *from* SF *to* another bug tracker is to improve the situation, surely. The current situation is that the limitations and intermittant failures of the SF tracker sufficiently impede the Python development process that some people were motivated to do the work to find a better alternative. You already seem to acknowledge that using free-software tools to develop Python is desirable. The committee already said so by saying that with other things equal, it would choose Roundup. I don't see why you're being so obtuse I think name calling is out of line here. Correct, besides which Ben seems to feel people are disagreeing on the desirability of using open source software when in fact they are mostly disagreeing about the *practicality* in this particular instance. Compellingly absent from most critics' output is a statement to the effect that they will volunteer their time to encourage the adoption of Roundup, which is excluded only by the absence of a support infrastructure. Time to shit or get off the pot, I'd say. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
Re: Urlnames in urllib2
At Wednesday 4/10/2006 21:03, goyatlah wrote: I'm trying to figure out how to get the exact opened url after a urlopen in urllib2. Say you have a link : http://myhost/mypath : what do I get back, - the file mypath on myhost - the file index.html on myhost/mypath, - or maybe something else. You get whatever the webserver chooses to serve at that URI. Usually: - if mypath is a directory (or assimilable to a directory), you get a redirect to mypath/ (else relative references won't work) - for mypath/ you get the default document for that directory, maybe index.html or index.php or default.html or ... - for mypath/myname you should get the best choice of documents regarding the Accept, Accept-Language, Accept-Encoding (but few people/servers use them completely). Snd what about the following: http;//myhost/index.htm where index.htm is actually a directory. Probably you would get a redirect to http://myhost/index.htm/ With urllib2.geturl() I can find out if the name is changed to mypath/ or index.htm/ but it seems that is the only thing I can find out. This is the HTTPRedirectHandler doing its work. You could look at the Content-Location header, but I doubt you could get much more info about the actual object retrieved - there are proxies, rewrite rules, virtual hosts... Gabriel Genellina Softlab SRL __ Preguntá. Respondé. Descubrí. Todo lo que querías saber, y lo que ni imaginabas, está en Yahoo! Respuestas (Beta). ¡Probalo ya! http://www.yahoo.com.ar/respuestas -- http://mail.python.org/mailman/listinfo/python-list
Re: Definition of '1j'?
At Wednesday 4/10/2006 21:43, [EMAIL PROTECTED] wrote: I'm wondering how/where the syntax for, e.g., 1j is defined. Is it something I can define myself? In particular, I make very heavy use of Nope - it's hardcoded inside the parser (see tokenizer.c) a complex unit other than j (I'll call it 1k=exp(pi*1j/3)), and it would be terribly convenient to make my own complex class based on this unit, which would construct and display results in this form, i.e. (1+2k)*1k -2+3k It's not a terrible inconvenience if this is not possble, since I can just define K=mycomplex(0,1), but I really do like the 1j notation, and the problem with the other notation is that K could easily get overwritten (and thus suggests I need a better name), while 1k would take intention to mess up. For a thing like 3k to be recognized as a complex number I'm afraid the only option would be to modify the Python sources. Gabriel Genellina Softlab SRL __ Preguntá. Respondé. Descubrí. Todo lo que querías saber, y lo que ni imaginabas, está en Yahoo! Respuestas (Beta). ¡Probalo ya! http://www.yahoo.com.ar/respuestas -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Fredrik Lundh wrote: Steve Holden wrote: you're not on the infrastructure list, I hear. python.org could still need a few more roundup volunteers, but it's not like nobody's prepared to con- tribute manhours. don't underestimate the community. No, I'm not on the infrastructure list, but I know that capable people *are*: and you know I am quite capable of donating my time to the cause, when I have it to spare (and sometimes even when I don't). what I was trying to say (between the lines) was that not only have the people on that list worked hard to do the evaluation (not to mention all the developers around the world that has worked even harder to set up test trackers), there's also been a good community response to the committee's call for 6-10 volunteers. Excellent. I've just complained elsewhere in this thread that those dissenting didn't appear to want to rectify the situation by offering their time. It would be nice to be wrong about that. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Ilias Lazaridis wrote: Giovanni Bajo wrote: Hello, I just read this mail by Brett Cannon: http://mail.python.org/pipermail/python-dev/2006-October/069139.html where the PSF infrastracture committee, after weeks of evaluation, recommends using a non open source tracker (called JIRA - never heard before of course) for Python itself. Does this smell Bitkeeper fiasco to anyone else than me? -- Giovanni Bajo Fascinating. The python foundation suggests a non-python non-open-source bugtracking tool for python. It's like saying: The python community is not able to produce the tools needed to drive development of python forward. Anyway. The whole selection process is intransparent. The commitee should have stated goals and requirements with a public verification of the tools against them. Is there any stick in the known universe that you will grasp the *right* end of? http://wiki.python.org/moin/OriginalCallForTrackers regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Steve Holden wrote: Excellent. I've just complained elsewhere in this thread that those dissenting didn't appear to want to rectify the situation by offering their time. It would be nice to be wrong about that. the dissenting won't contribute a thing, of course. they never ever do. but not everyone is wired that way. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Steve Holden [EMAIL PROTECTED] writes: And I'd prefer it if you'd drop this subject. So, if you have nothing new to say, kindly leave it. I'm happy to, but: You appear to be prepared to go to any length short of providing effort to support the open source tracker. This was addressed in a previous post. I don't have the skills nor the resources to do this. Yes, as has been pointed out, it actually *is* far less effort to point out problems, than to solve them. That doesn't detract from the value of pointing out problems. This thread was started on the shock of realising that a non-free tool was even being *considered* for the new Python bug tracker. Those are the terms on which I've been arguing. Apparently there are some people who *have* put themselves forward to support a free-software tool. Great! My point all along has been that Python's developers are well advised to consider *only* free-software tools for supporting development of Python, and that from among those the best tool for the job should be chosen. As you say, nothing new has been said now for a while, so in the absence of that I'm happy to leave it here. -- \Why, I'd horse-whip you if I had a horse. -- Groucho Marx | `\ | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Hands on Documentation for Python methods and Library
At Thursday 5/10/2006 01:54, Wijaya Edward wrote: One can do the following with Perl $ perldoc -f chomp $ perldoc -f function_name or $ perldoc List::MoreUtils $ perldoc Some::Module Can we do the same thing in Python? s/perl/py/g See the pydoc module. Gabriel Genellina Softlab SRL __ Preguntá. Respondé. Descubrí. Todo lo que querías saber, y lo que ni imaginabas, está en Yahoo! Respuestas (Beta). ¡Probalo ya! http://www.yahoo.com.ar/respuestas -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
[Ben Finney] I don't see why you're being so obtuse [Terry Reedy] I think name calling is out of line here. Name calling is always out of line on comp.lang.python. Unless it's done by Guido. Then it's OK. Anyone else, just remind them that even Hitler had better manners. That always calms things down again. loving-usenet-despite-that-it's-usenet-ly y'rs - tim -- http://mail.python.org/mailman/listinfo/python-list
Re: CGI Tutorial
Clodoaldo Pinto Neto schrieb: http://webpython.codepoint.net Great tutorial -- Thanks a lot!!! :D -- Gerold Penz - bcom - Programmierung [EMAIL PROTECTED] | http://gerold.bcom.at | http://sw3.at Ehrliche, herzliche Begeisterung ist einer der wirksamsten Erfolgsfaktoren. Dale Carnegie -- http://mail.python.org/mailman/listinfo/python-list
user modules
Hi, I'm writing a python program to analyse and export volumetric data. To make development and extension easier, and to make it more useful to the public when it is released (LGPL), I would like to enable users to place their own python files in a user_extensions directory. These files would implement a common interface in order for the main program to be able to read them and execute the necessary code. My question is what is the best way of implementing this? I have investigated importing them as modules, but unless the user modifies the main program I cannot see how the main program can learn of the existence of specific modules. For example: from user_modules import * # directory 'user_modules' contains __init__.py allowing this # From here I would need a list of the imported modules, in order to # execute a common command on each of them, such as for module in imported_modules: module.initialise() module.get_tab_window() How do I get from the first bit to the second bit, or is there a better way of obtaining the functionality I need? --Cameron. -- http://mail.python.org/mailman/listinfo/python-list
Assertion in Python
Hi All, I want to do verification in my scripts. So for that what i am doing here are shown below: 1. Telnet to one router. 2. Configure router. 3. Configure routing. Now after doing all these i have to check showinterfaces. So i execute command show interface and saved the output in one file. Now the problem which i am facing is how to do assertion from that output. e.g output is something like this eth0 is up OSPF not enabled on this interface eth1 is up Internet Address 192.168.1.2/24, Area 0.0.0.0 Router ID 192.168.1.2, Network Type BROADCAST, Cost: 10 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 192.168.1.2, Interface Address 192.168.1.2 No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:00 Neighbor Count is 0, Adjacent neighbor count is 0 eth2 is up OSPF not enabled on this interface eth3 is down OSPF not enabled on this interface lo is up OSPF not enabled on this interface sit0 is down OSPF not enabled on this interface In this i want to check Designated Router (ID) 192.168.1.2. If this is the same Ip which i have gice in configuration then test case will get pass otherwise Fail. Can somebody send me the code how to do this. Thanks in Advance Vikram Malhotra -- http://mail.python.org/mailman/listinfo/python-list
Re: Python/Tkinter crash.
On Wed, 04 Oct 2006 20:02:56 +0200, Hendrik van Rooyen
[EMAIL PROTECTED] wrote:
Eric Brunel [EMAIL PROTECTED] wrote:
I know the problem happens sometimes on one of my Tkinter applications,
but I never succeeded in reproducing it systematically. I've browsed the
tcl bugs, but didn't find anything. Maybe you'll be luckier than I... If
you are, I'm interested in any hint you can find.
Ouch! - this is a bit the wrong answer...
Sorry for that. I realize I wasn't very helpful, here...
What I have seen, in mucking about today, is that it seems to be related
to
threading - I have a silly sort of thread that runs, updating my meters,
more or
less continuously, to simulate data from the field - it just adds some
values to
the seven display variables and calls the update methods that delete and
redraw
the arcs representing the analogue style meters, deleting and replacing
the text
objects that show the values, and then it sleeps for a while, and does
it all
again.
At the same time, one other thread (other than the main thread), can be
created
to move a component on the canvas around by calling its delete and draw
methods. - but this is also done more or less continuously, as a new
thread is
created as soon as the previous one dies to move the next object around.
Now these two things are asynchronous with each other, so that given
enough
time, they are bound to make calls to Tkinter in a re-entrant fashion,
and I
suspect that it is this that is causing the problem - my evidence for
this is
that I implemented a boolean as a sort of lock and had the Meter
updating back
down in favour of the other animation to try and avoid any sort of re -
entrancy
to the Tkinter canvas object's delete and draw methods...
AFAIK, Tkinter is not thread safe. Using some kind of lock to serialize
the calls from different threads may seem to work (I never tested it
actually), but the safest way I found to use threads with Tkinter was to
call it only from the thread where the main loop executes. The only thing
that seems to work reliably in secondary threads is to generate custom
events (widget.event_generate('MyCustomEvent', when='tail')), and to
treat them in Tkinter's thread via bindings
(widget.bind('MyCustomEvent', treatment_command)). This makes things a
bit messy, but it works quite well.
Now, as I said before, someone reported that he *did* get the error you
got from time to time. So maybe the problem I have is not the same as
yours, or maybe there are some cases in my application where Tkinter stuff
still gets called directly from secondary threads. I'll try to investigate
that when I've time and I'll keep you informed.
HTH a little this time...
--
python -c print ''.join([chr(154 - ord(c)) for c in
'U(17zX(%,5.zmz5(17l8(%,5.Z*(93-965$l7+-'])
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Ben Finney wrote: Steve Holden [EMAIL PROTECTED] writes: And I'd prefer it if you'd drop this subject. So, if you have nothing new to say, kindly leave it. I'm happy to, but: You appear to be prepared to go to any length short of providing effort to support the open source tracker. This was addressed in a previous post. I don't have the skills nor the resources to do this. Yes, as has been pointed out, it actually *is* far less effort to point out problems, than to solve them. That doesn't detract from the value of pointing out problems. This thread was started on the shock of realising that a non-free tool was even being *considered* for the new Python bug tracker. Those are the terms on which I've been arguing. Apparently there are some people who *have* put themselves forward to support a free-software tool. Great! My point all along has been that Python's developers are well advised to consider *only* free-software tools for supporting development of Python, and that from among those the best tool for the job should be chosen. As you say, nothing new has been said now for a while, so in the absence of that I'm happy to leave it here. In case readers are puzzled by the absence of the message to which Ben replies above I should perhaps explain that I cancelled it having decided that its language was immoderate and unfair to Ben. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
Re: Python/Tkinter crash.
Eric Brunel wrote: AFAIK, Tkinter is not thread safe. Using some kind of lock to serialize the calls from different threads may seem to work (I never tested it actually), but the safest way I found to use threads with Tkinter was to call it only from the thread where the main loop executes. the Tkinter binding contains some code that attempts to deal with re- entrant calls, but I don't know/remember to what extent it's actually supposed to work (in other words, if the observed problems are bugs or just limitations). (maybe Martin's memory is better?) anyway, I usually play it safe and make sure to use a single thread to deal with the UI. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: How can I correct an error in an old post?
Jorgen Grahn [EMAIL PROTECTED] wrote: On Mon, 02 Oct 2006 16:36:24 +0100, Steve Holden [EMAIL PROTECTED] wrote: I'd appreciate it if all concerned would close this thread now. I think you are overreacting. This was a thread with three (3) postings, in a high-volume newsgroup, with no indication that it would continue (except maybe with a pointer to whatever posting the OP wanted to correct, or to his correction). I'm confused. I assumed Steve was just joking with his original request. Although it might be mirrored on a web site somewhere, this is a Usenet newsgroup. It is impossible to close a thread. The concept simply does not exist. -- - Tim Roberts, [EMAIL PROTECTED] Providenza Boekelheide, Inc. -- http://mail.python.org/mailman/listinfo/python-list
Re: hex sending
hiroc [EMAIL PROTECTED] wrote: s.send(abc) # send test string I need to send hex:10 06 00 0f 02 bc d1 instead of abc hoW? One ugly way is s.send( \x10\x06\x00\x0f\x02\xbc\xd1 ) -- - Tim Roberts, [EMAIL PROTECTED] Providenza Boekelheide, Inc. -- http://mail.python.org/mailman/listinfo/python-list
Re: Assertion in Python
At Thursday 5/10/2006 04:09, vmalhotra wrote:
Now the problem which i am facing is how to do assertion from that
output. e.g output is something like this
eth0 is up
OSPF not enabled on this interface
eth1 is up
Internet Address 192.168.1.2/24, Area 0.0.0.0
Router ID 192.168.1.2, Network Type BROADCAST, Cost: 10
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 192.168.1.2, Interface Address 192.168.1.2
No backup designated router on this network
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:00
Neighbor Count is 0, Adjacent neighbor count is 0
eth2 is up
OSPF not enabled on this interface
eth3 is down
OSPF not enabled on this interface
lo is up
OSPF not enabled on this interface
sit0 is down
OSPF not enabled on this interface
In this i want to check Designated Router (ID) 192.168.1.2.
This is the idea (assuming you have already read and split the output
on lines):
for line in output:
line = line.strip()
if line.startswith('Designated Router (ID)'):
ipReadStr = line[line.find('(ID)')+4:] # just before the IP starts
ipReadStr = ipReadStr.split(',',1)[0].strip() # up to the next ,
assertEqual(ipReadStr, ipExpected)
break
else:
fail('Designated Router (ID) not found')
Gabriel Genellina
Softlab SRL
__
Preguntá. Respondé. Descubrí.
Todo lo que querías saber, y lo que ni imaginabas,
está en Yahoo! Respuestas (Beta).
¡Probalo ya!
http://www.yahoo.com.ar/respuestas
--
http://mail.python.org/mailman/listinfo/python-list
Re: hex sending
hiroc [EMAIL PROTECTED] writes: s.send(abc) # send test string I need to send hex:10 06 00 0f 02 bc d1 instead of abc See the binascii module: import binascii # a2b_hex stands for ascii to binary conversion, hex format # you must remove the spaces binary = binascii.a2b_hex (1006000f02bcd1) s.send (binary) -- http://mail.python.org/mailman/listinfo/python-list
Re: Long Tkinter Menu
On Thu, 05 Oct 2006 02:33:54 +0200, Dustan [EMAIL PROTECTED] wrote:
I don't know if this is because of Tkinter (ie Tk) itself or the
Windows default way of handling things, but when I create a very long
menu (my test is shown below), the way it displays is rather sucky; the
menu stretches from the top of the moniter's window to the bottom (no
matter the size of the actual application).
Is there any alternative format for how a long menu gets displayed? It
would be nice if say, I could make the menu only go to the borders of
the application itself (in this case, not that long).
To limit the menu in the application window, will be difficult. But here
are two ways of automatically limiting the number of entries that can
appear in a menu by specializing the Tkinter Menu class:
--
from Tkinter import *
class LongMenu(Menu):
Automatically creates a cascade entry labelled 'More...' when the
number of entries is above MAX_ENTRIES.
MAX_ENTRIES = 20
def __init__(self, *args, **options):
Menu.__init__(self, *args, **options)
self.nextMenu = None
def add(self, itemType, cnf={}, **kw):
if self.nextMenu is not None:
return self.nextMenu.add(itemType, cnf, **kw)
nbEntries = self.index(END)
if nbEntries LongMenu.MAX_ENTRIES:
return Menu.add(self, itemType, cnf, **kw)
self.nextMenu = LongMenu(self)
Menu.add(self, 'cascade', label='More...', menu=self.nextMenu)
return self.nextMenu.add(itemType, cnf, **kw)
class AutoBreakMenu(Menu):
Automatically adds the 'columnbreak' option on menu entries to make
sure that the menu won't get too high.
MAX_ENTRIES = 20
def add(self, itemType, cnf={}, **kw):
entryIndex = 1 + (self.index(END) or 0)
if entryIndex % AutoBreakMenu.MAX_ENTRIES == 0:
cnf.update(kw)
cnf['columnbreak'] = 1
kw = {}
return Menu.add(self, itemType, cnf, **kw)
if __name__ == '__main__':
root = Tk()
menubar = Menu(root)
def fillMenu(menu):
for i in xrange(100):
menu.add_command(label=str(i), command=root.quit)
menu.add_command(label=Exit, command=root.quit)
menu1 = LongMenu(menubar, tearoff=0)
fillMenu(menu1)
menu2 = AutoBreakMenu(menubar, tearoff=0)
fillMenu(menu2)
menubar.add_cascade(label=Test1, menu=menu1)
menubar.add_cascade(label=Test2, menu=menu2)
root.config(menu=menubar)
root.mainloop()
--
If your application is more complicated than that (e.g if you insert menu
entries after the first adds), you'll have to change the code above a bit,
since it doesn't handle calls to insert at all. But you get the idea.
HTH
--
python -c print ''.join([chr(154 - ord(c)) for c in
'U(17zX(%,5.zmz5(17l8(%,5.Z*(93-965$l7+-'])
--
http://mail.python.org/mailman/listinfo/python-list
Re: A Universe Set
Wildemar Wildenburger [EMAIL PROTECTED] wrote: Jorgen Grahn wrote: - the wildcard object, which compares equal to everything else - infinite xrange()s - the black hole function 'def f(*args): pass' - the identity function 'def f(x): return x' Any use cases for these? I guess the first one could be useful if you want to compare two data structures but prune part of the structure in the comparison (e.g. in a unit test assertion). So not forgetting that this only works when the wildcard is on the left of the comparison: class DontCareClass(object): def __eq__(self, other): return True dontcare = DontCareClass() [1, dontcare, 3]==[1, 2, 3] True [1, dontcare, 3]==[1, 4, 3] True [1, dontcare, 3]==[1, 4, 2] False I think for more general use though it's a non-starter. If Python had it builtin it should compare equal in *all* situations and what on earth should aDict[dontcare] do? I can think of one use for a black hole function, but it is very specific. It would be kind of nice to have a variation on 'super' which traps AttributeError and returns the black hole instead, or perhaps just an optional third argument for a default to return (c.f. dict.get). So you could write: class C(object): def method(self, arg): super(C, self, blackhole).method(arg) ... whatever ... and method would call any base class definition of method but not care if there isn't one. The alternative to this is either to catch and ignore the exception (which is a pain), or better to create a dummy base class which implements the interface but doesn't propagate the calls. I suppose the same argument could be made for any pattern of calling the result of getattr when the attribute might not exist. Replace: m = getattr(obj, key, None) if m is not None: m(something) or: if hasattr(obj, 'somekey'): obj.somekey(whatever) with: getattr(obj, key, blackhole)(something) The catch here is that the current pattern often has an 'else' clause as well and you can't replace those ones with blackhole. -- http://mail.python.org/mailman/listinfo/python-list
Applications written in TkInter
Hi, I wonder, if there is a site with a collection of written TkInter programs. I did not find any summary. for pyGtk there exist for example: http://www.pygtk.org/applications.html and for wxPython: http://wiki.wxpython.org/index.cgi/wxPythonPit_Apps -- Franz Steinhaeusler -- http://mail.python.org/mailman/listinfo/python-list
Re: Where is Python in the scheme of things?
gord wrote:
As a complete novice in the study of Python, I am asking myself where this
language is superior or better suited than others. For example, all I see in
the tutorials are lots of examples of list processing, arithmetic
calculations - all in a DOS-like environment.
s/DOS-like/command line/
The command line interface is widely used on unix-like systems, and is
very handy for a lot of things.
What is particularly disappointing is the absence of a Windows IDE,
components and an event driven paradigm.
Disappointing ? Python is a general-purpose, cross-platform language,
not a Windows-only GUI-only environment. What you're looking for does
exist, but as 3rd part libs and programs. You could check Boa
Constructor (a wxPython based Delphi-like RAD/IDE), or any combination
of a Windows-compatible GUI toolkit / GUI builder / IDE.
How does Python stand relative to
the big 3, namely Visual C++, Visual Basic and Delphi?
Ever tried writing a cross-platform web application server with any of
these big 3 ?
I realize that these
programming packages are quite expensive
and Windows-only, and proprietary...
now while Python is free
free as in free beer, yes, but also free as in free speech. And
Python is portable too (most of my programs would run on Windows or
MacOS X or BSD etc without any modification).
(at least
for the package I am using - ActivePython).
Please discuss where Python shines.
Application programming and admin scripts. Note that application
programming doesn't imply GUI - I'm mostly doing web development FWIW.
Now if you're doing Windows-only, Python is quite good with COM/ActiveX
etc AFAIK.
--
bruno desthuilliers
python -c print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in '[EMAIL PROTECTED]'.split('@')])
--
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Re: Python to use a non open source bug tracker?
Ilias Lazaridis wrote: Giovanni Bajo wrote: Hello, I just read this mail by Brett Cannon: http://mail.python.org/pipermail/python-dev/2006-October/069139.html where the PSF infrastracture committee, after weeks of evaluation, recommends using a non open source tracker (called JIRA - never heard before of course) for Python itself. Does this smell Bitkeeper fiasco to anyone else than me? -- Giovanni Bajo Fascinating. The python foundation suggests a non-python non-open-source bugtracking tool for python. Actually, it suggests two bugtracking tools, one of them written in Python. It's like saying: The python community is not able to produce the tools needed to drive development of python forward. No, it's saying: if the Python community is able to provide the required amount of time to do the admin work, we'll use the tool written in Python. Anyway. The whole selection process is intransparent. Steve has already pointed you to the wiki page. Georg -- http://mail.python.org/mailman/listinfo/python-list
Re: Python/Tkinter crash.
Russell E. Owen [EMAIL PROTECTED] wrote: In article [EMAIL PROTECTED], Hendrik van Rooyen [EMAIL PROTECTED] wrote: Hi, I get the following: [EMAIL PROTECTED]:~/Controller/lib python display.py UpdateStringProc should not be invoked for type font Aborted ... Everything seems to work fine. - there is a thread that runs to move the meter values around continuously, and this has been stable for some time now, and I can get the various machine parts to move around the screen by pushing the buttons... You mention threads several times in your posting. Do you have multiple threads talking to Tkinter? If so, try recoding to avoid this (e.g. by having the background threads communicate with the main thread via Queues). -- Russell I am not sure how to do this - once I have called the Tkinter mainloop - that main thread is essentially event driven - and figuring out how to get it to poll a queue for content is not obvious - I suppose I could arrange some external wake up event that I could activate to make it look at the queue - must read up on this... Thanks it is a good idea as it will make the interface cleaner, and as I have to sort out inter process communication anyway it will make sense to also use a queueing mechanism between the threads in this display process. There is already one queue defined - but its a hack as I use it to pass the main threads id to get around the problem of referring to a class before its defined... - Hendrik -- http://mail.python.org/mailman/listinfo/python-list
Re: Python/Tkinter crash.
Hendrik van Rooyen [EMAIL PROTECTED] wrote: Eric Brunel [EMAIL PROTECTED] wrote: On Wed, 04 Oct 2006 10:33:55 +0200, Hendrik van Rooyen [EMAIL PROTECTED] wrote: Hi, I get the following: [EMAIL PROTECTED]:~/Controller/lib python display.py UpdateStringProc should not be invoked for type font Aborted and I am back at the bash prompt - this is most frustrating, as there is no friendly traceback to help me guess where its coming from. And what is worse, the script runs for a varying time before it simply exits like this. What can I do to dig deeper to try to find a clue? - I don't even know if its Python, Tkinter or Linux... Neither of them: it's a tcl problem. The message you get is in the file generic/tclObj.c in the tcl source directory. I know the problem happens sometimes on one of my Tkinter applications, but I never succeeded in reproducing it systematically. I've browsed the tcl bugs, but didn't find anything. Maybe you'll be luckier than I... If you are, I'm interested in any hint you can find. Ouch! - this is a bit the wrong answer... What I have seen, in mucking about today, is that it seems to be related to threading - I have a silly sort of thread that runs, updating my meters, more or less continuously, to simulate data from the field - it just adds some values to the seven display variables and calls the update methods that delete and redraw the arcs representing the analogue style meters, deleting and replacing the text objects that show the values, and then it sleeps for a while, and does it all again. At the same time, one other thread (other than the main thread), can be created to move a component on the canvas around by calling its delete and draw methods. - but this is also done more or less continuously, as a new thread is created as soon as the previous one dies to move the next object around. Now these two things are asynchronous with each other, so that given enough time, they are bound to make calls to Tkinter in a re-entrant fashion, and I suspect that it is this that is causing the problem - my evidence for this is that I implemented a boolean as a sort of lock and had the Meter updating back down in favour of the other animation to try and avoid any sort of re - entrancy to the Tkinter canvas object's delete and draw methods... Now the Jury is still out on this - it seems to have helped, as the thing has been running for some hours now without crashing - but maybe I have just applied a band aid to sword cut - I don't know - if it runs through the night I will feel much better... Will update again as soon as I have more data... OK - It has run through the night and as I type it is still running, so the band aid has helped a bit... Eric - if you are interested and contact me, then I will comment out the fix and email you the bits that you need to run this horror - if you need a reliably failing thingy to study the problem with :-) It was your post yesterday or so in another thread here that prompted me to try this style of fix... Thank you. BTW - I am curious - in your app that exhibits the same crash - what did you do to work around the problem ? - Is it also running a thread and calling methods that are normally event driven commands in the main thread? Or two other threads like me? It would be interesting to try to spot any similarities... Is it even allowed to asynchronously call a main thread method from another thread? - it seems to work - but I am not sure why it does - what is the main thread's mainloop doing while this is going on? - your other comment in the other thread here implies that it is a strict no - no... Is it safe to call invoke from another thread? - what is the difference between calling invoke and calling the bound method directly? - Hendrik -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Georg Brandl wrote: The python foundation suggests a non-python non-open-source bugtracking tool for python. Actually, it suggests two bugtracking tools, one of them written in Python. the announcemant's subject line said recommendation for a new issue tracker, though; not we need the community's help before we can make a final recommendation. in fact, only 20% of the announcement talked about Python; the rest was something that looked a lot like a press release from the non-python hosting company, so it's not that strange that people missed the few sentences in the middle that explained that the subject line wasn't entirely accurate. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Fredrik Lundh wrote: Georg Brandl wrote: The python foundation suggests a non-python non-open-source bugtracking tool for python. Actually, it suggests two bugtracking tools, one of them written in Python. the announcemant's subject line said recommendation for a new issue tracker, though; not we need the community's help before we can make a final recommendation. Granted. in fact, only 20% of the announcement talked about Python; the rest was something that looked a lot like a press release from the non-python hosting company, so it's not that strange that people missed the few sentences in the middle that explained that the subject line wasn't entirely accurate. I actually stopped reading after Brett's signature, so I didn't have the 20% figure in my mind :) Georg -- http://mail.python.org/mailman/listinfo/python-list
Re: Python/Tkinter crash.
Hendrik van Rooyen [EMAIL PROTECTED] writes: I am not sure how to do this - once I have called the Tkinter mainloop - that main thread is essentially event driven - and figuring out how to get it to poll a queue for content is not obvious - I suppose I could arrange some external wake up event that I could activate to make it look at the queue - must read up on this... http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/82965 -- http://mail.python.org/mailman/listinfo/python-list
Re: Access to static members from inside a method decorator?
[EMAIL PROTECTED] wrote:
I'm developing a library at the moment that involves many classes, some
of which have exposed capabilities. I'm trying to design a nice
interface for both exposing those capabilities, and inspecting
instances to find out what capabilities they have.
At the moment, I'm leaning towards a superclass (Exposed) that defines
a static method which is a decorator (expose) such that any derived
class can mark a method with @Exposed.expose and it will then be later
returned by getExposedMethods(), a la:
class Exposed:
@staticmethod
def expose( f ):
...
def getExposedMethods( self ):
...
class Person( Exposed ):
@Exposed.expose
def talk( self, ... ):
...
I'm trying to implement the decorator by having it populate a static
member list of whatever class it's in with a reference to the method.
getExposedMethods() would then return the contents of each of those
lists from itself back to Exposed in the class hierarchy. The first
problem was that having a reference to the method (i.e. talk()) does
not allow you to get a reference to the enclosing class (I had hoped
im_class would lead me there).
Not yet. When your decorator is called, the class object is not yet
created, and what you are decorating is a plain function.
The real hiccup was that explicitly
passing the class as an argument to the decorator generates a undefined
global name error, presumably because at that point of execution the
class object hasn't been fully created/initialised.
Exactly.
So how can this be done?
The simplest thing is to use a two-stages scheme : mark the functions as
exposed, then collect them:
def expose(func):
func._exposed = True
return func
def exposed(obj):
return callable(obj) and getattr(obj, '_exposed', False)
class Exposing(object):
@classmethod
def get_exposed_methods(cls):
try:
exposeds = cls._exposed_methods
except AttributeError:
exposeds = []
for name in dir(cls):
obj = getattr(cls, name)
if exposed(obj):
exposeds.append(obj)
cls._exposed_methods = exposeds
return exposeds
class Parrot(Exposing):
@expose
def parrot(self, what):
return %s says %s % (self, str(what))
HTH
--
bruno desthuilliers
python -c print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in '[EMAIL PROTECTED]'.split('@')])
--
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embedding python -- windows specify problems
Hi all I have been working on some new code that embeds python in an C application. The embedding is working fine under Linux but crashing under Windows (XP) when I reach the following step. PyRun_AnyFile(f,name); If there's some python exception being thrown by the PyRun_AnyFile call, how can I retrieve it from C? Even when the file (f) being run by Python contains only a 'print' statement, the application still crashes on WinXP. The linking to Python seems to be working OK, and the following C code that precedes the above PyRun_AnyFile statement seems to be working fine: PyRun_SimpleString(import ascpy); PyRun_SimpleString(L = ascpy.Library()); PyRun_SimpleString(print L); Can anyone suggest what some good diagnostic steps would be? My embedding code is at the following link. I'm happy to explain the architecture in more detail if that helps. https://pse.cheme.cmu.edu/svn-view/ascend/code/branches/extfn/models/johnpye/extpy/ Any suggestions very much appreciated! Cheers JP -- http://mail.python.org/mailman/listinfo/python-list
Re: Hands on Documentation for Python methods and Library
Wijaya Edward wrote: One can do the following with Perl $ perldoc -f chomp $ perldoc -f function_name $ pydoc dir $ pydoc function_name or $ pydoc math $ pydoc module_name Richard -- http://mail.python.org/mailman/listinfo/python-list
Re: Python to use a non open source bug tracker?
Martin v. Löwis wrote: In fact, are you absolutely positive that you need so much effort to maintain an existing bugtracker installation? I know for sure that GCC's Bugzilla installation is pretty much on its own; Daniel Berlin does some maintainance every once in a while (upgrading when new versions are out, applying or writing some patches for most requested features in the community, or sutff like that), but it's surely not his job, not even part-time. Daniel Berlin has put a tremendous amount of work into it. I know, because I set up the first bug tracker for gcc (using GNATS), and have been followed the several years of pondering fairly closely. It was quite some work to set up GNATS, and it was even more work to setup bugzilla. For Python, we don't have any person similar to Daniel Berlin (actually, we have several who *could* have done similar work, but none that ever volunteered to do it). Don't underestimate the work of somebody else. Martin, I am by no means understimating Daniel's work. I am just noting that the spare-time work he did is, by definition, much much lower than the 6-10 people that the PSF infrastructure committee is calling for. I would like this statement to be officially reduced to 2-3 people, since it is *really* not required much more than that to setup a bug tracker installation, and no more than 1 person to maintain it afterwards. *IF* there are more volunteers, that's good, they can offload the maintenance work from a single maintainer; but I think it's unfair to put such a high *requisite*. We do not have 6-10 people maintaining SVN afterall, even if you wish we had :) -- Giovanni Bajo -- http://mail.python.org/mailman/listinfo/python-list
Multiple calls to logging.config.fileConfig
Hi, our applications can have plugins as subpackages and I'd like to allow them to use their own logger as well as it's configuration. I thought that best way will be their own configuration file passed to fileConfig. However, I run into problems... 1) It seems that I cannot refer to something from previously loaded files, i.e. I'd like application config file to specify formatters and handlers and plugins only referring them. 2) I'm not sure about appending loggers; if I specify [loggers] keys: web and then [loggers] keys: syncml Will web not be overwritten? 3) Finally, I run into root problem. In second call, if I specify root logger again: [loggers] keys: root,web (...) [logger_web] level: WARNING qualname: xxx.web handlers: console I'll get Traceback (most recent call last): File /usr/lib/python2.4/logging/config.py, line 143, in fileConfig llist.remove(root) If I'll set only web as logger, I'll get standard NoSectionFound exception. Any idea how to fix this? It seems that I have to write custom parser merging all files and config logging directly from code, but I'd like to assure that it's the standard way... Regards, Almad -- http://mail.python.org/mailman/listinfo/python-list
Re: embedding python -- windows specify problems
John Pye wrote:
I have been working on some new code that embeds python in an C
application. The embedding is working fine under Linux but crashing
under Windows (XP) when I reach the following step.
PyRun_AnyFile(f,name);
If there's some python exception being thrown by the PyRun_AnyFile call,
how can I retrieve it from C?
Even when the file (f) being run by Python contains only a 'print'
statement, the application still crashes on WinXP.
the contents and the layout of the FILE structure isn't defined, so
PyRun_AnyFile()
only works if you make sure to open the file using *exactly* the same run time
library
as Python itself uses.
it's usually easier to hand the problem over to the interpreter:
PyRun_SimpleString(execfile('myscript.py')\n);
the same approach can be used to implement custom error handling, stdout/stderr
redirects, etc.
/F
--
http://mail.python.org/mailman/listinfo/python-list
Re: embedding python -- windows specify problems
the contents and the layout of the FILE structure isn't defined isn't standardized, that is. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: dictionary of list from a file
limodou wrote:
On 4 Oct 2006 13:11:15 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote:
limodou wrote:
here is my program
d = {}
for line in file('test.txt'):
line = line.strip()
if line:
k, v = line.strip().split()
d.setdefault(k, []).append(v)
print d
Minor nits: you call strip twice, when you don't need to. just omit
the second call.
Yes, I forgot that.
Also, I'm not sure stripping the line is the right thing per the spec;
d = {}
for line in [l[:-1] for l in file('test.txt', 'rU') if len(l)1]:
k,v = line.split()
d.setdefault(k,[]).append(v)
[l[:-1] for l in file('test.txt', 'rU') if len(l)1]
this line I think will create a list, and if the file is large, it'll
consume many memory I think.
And I think using strip is more clear than list comprehension, except
for the memory consume.
Good point on memory.
You can use strip in a list (or generator) comprehension just fine.
For example (using a generator to avoid memory consumption):
for line in (l.rstrip(\n) for l in file(test.txt, rU) if l[0] !=
\n):
k, v = line.split()
d.setdefault(k, []).append(v)
It's a matter of taste, but I think this isolates the bean-counting
get rid of newlines/blank lines stuff from the real processing and
makes it a bit clearer what real work you're doing with each line.
--
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Re: Python/Tkinter crash.
Fredrik Lundh [EMAIL PROTECTED] wrote: Eric Brunel wrote: AFAIK, Tkinter is not thread safe. Using some kind of lock to serialize the calls from different threads may seem to work (I never tested it actually), but the safest way I found to use threads with Tkinter was to call it only from the thread where the main loop executes. the Tkinter binding contains some code that attempts to deal with re- entrant calls, but I don't know/remember to what extent it's actually supposed to work (in other words, if the observed problems are bugs or just limitations). (maybe Martin's memory is better?) anyway, I usually play it safe and make sure to use a single thread to deal with the UI. /F I must be dense - After I have called mainloop, if I have not started another thread to respond to events that are not generated by the user on the screen (in this case values of variables to display from the field generated by different processes - there is other hardware out there), how do I get control back to do the necessary updating? - I suppose I can use the call back after some time thingy to implement a polling loop - possibly as Russel Owen suggested - by polling a queue - but queues are for between threads - and I have seen here somewhere that sockets also want to be the main thread - so that leaves a pipe - and I have had bad experiences with pipes that are unblocked, and if I don't unblock it, then the gui will grind to a haltso I need a thread for the pipe between processes, and a queue between threads, and a time out based polling loop to read the queue, it seems - is it even safe to change a main loop variable from another thread? , or should I do it all via commands through a queue, implementing a whole goddam serial protocol just between threads? and If I don't have another thread to do the timing for the animation bits, then I must base that on a timed callback too, and somehow keep state between callbacks... now is it ok to call widget command methods from a callback in the same thread, or do I have to use invoke? My head is beginning to hurt... - what was a nice simple threaded implementation is turning into a spaghetti monster of timed callbacks - you thought gotos was bad? - you aint seen nothing yet... - Hendrik -- http://mail.python.org/mailman/listinfo/python-list
Re: dictionary of list from a file
[EMAIL PROTECTED] wrote: for line in (l.rstrip(\n) for l in file(test.txt, rU) if l[0] != \n): k, v = line.split() d.setdefault(k, []).append(v) Note that this snippet will produce the same output with or without the rstrip() method call. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Where is Python in the scheme of things?
gord wrote: As a complete novice in the study of Python, I am asking myself where this language is superior or better suited than others. I use it, and see it primarily, as a Perl killer. It also does for Ruby and our infernal shell scripts. I've never considered using Python instead of VB. As a VB developer of many years, I'd see thhe Python language itself as infinitely superior to VB in almost every aspect, except that of building event driven Windows GUIs with easy form layout. Maybe there's some wonderful Python toolkit for doing this, but it's news to me. I'm undecided as to whether Python beats JSP for web development. So far I'm still inclined to Java, but that's probably because I know Java and Java has a huge amount of beyond Java the language development attached to it for web work. -- http://mail.python.org/mailman/listinfo/python-list
Re: releasing memory to malloc
The memory manager in the latest Python release 2.5 does return freed memory to the underlying system, if possible. For more details, see the 5th bullet on this page http://docs.python.org/whatsnew/ports.html. /Jean Brouwers [EMAIL PROTECTED] wrote: The workaround I went with made use of the shelve module and calls to gc.collect() to cap the memory consumed by the Python allocator. It was a bit intrusive but it got the job done. Would a method in the gc module that released memory to malloc be something that could get added to Python? Or are there some reasons why allowing that would be a bad idea? Regards, Iker P.S. This may be a repeat of an earlier message - it seems that google groups may have discarded my earlier post. [EMAIL PROTECTED] wrote: Is there any way to get Python to release memory back to the C allocator? I'm currently running a script that goes through the following steps: 1) Creates a very large number of Python objects to produce a relatively small data structure that sits in a C extension. The Python objects consume quite a bit of memory. 2) Releases all the Python objects. 3) Invokes a function of said C extension for further processing. This step needs as much memory as possible. I'd like step 2 to return memory to the C allocator so that it is available to the extension in step 3 (which uses malloc). Regards, Iker Arizmendi -- http://mail.python.org/mailman/listinfo/python-list
Re: Python/Tkinter crash.
Paul Rubin http://[EMAIL PROTECTED] wrote: Hendrik van Rooyen [EMAIL PROTECTED] writes: I am not sure how to do this - once I have called the Tkinter mainloop - that main thread is essentially event driven - and figuring out how to get it to poll a queue for content is not obvious - I suppose I could arrange some external wake up event that I could activate to make it look at the queue - must read up on this... http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/82965 Thank you Paul - this shows how nicely! - Hendrik -- http://mail.python.org/mailman/listinfo/python-list
Why do this?
Ok, not really python focused, but it feels like the people here could explain it for me :) Now, I started programming when I was 8 with BBC Basic. I never took any formal classes however, and I have never become an expert programmer. I'm an average/hobbyist programmer with quite a few languages under my belt but I cant do any really fancy tricks with any of them. (although Python might be nudging me into more advanced things, now I'm starting to get what all the __method__ thingies and operators are all about) 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 hope I'm not being dense. The result is that I have pathalogically avoided print %s % (thing) because it seems to just over complicate things. Ta, :) Matt. This email is confidential and may be privileged. If you are not the intended recipient please notify the sender immediately and delete the email from your computer. You should not copy the email, use it for any purpose or disclose its contents to any other person. Please note that any views or opinions presented in this email may be personal to the author and do not necessarily represent the views or opinions of Digica. It is the responsibility of the recipient to check this email for the presence of viruses. Digica accepts no liability for any damage caused by any virus transmitted by this email. UK: Phoenix House, Colliers Way, Nottingham, NG8 6AT UK Reception Tel: + 44 (0) 115 977 1177 Support Centre: 0845 607 7070 Fax: + 44 (0) 115 977 7000 http://www.digica.com SOUTH AFRICA: Building 3, Parc du Cap, Mispel Road, Bellville, 7535, South Africa Tel: + 27 (0) 21 957 4900 Fax: + 27 (0) 21 948 3135 http://www.digica.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Long Tkinter Menu
Eric Brunel wrote:
On Thu, 05 Oct 2006 02:33:54 +0200, Dustan [EMAIL PROTECTED] wrote:
I don't know if this is because of Tkinter (ie Tk) itself or the
Windows default way of handling things, but when I create a very long
menu (my test is shown below), the way it displays is rather sucky; the
menu stretches from the top of the moniter's window to the bottom (no
matter the size of the actual application).
Is there any alternative format for how a long menu gets displayed? It
would be nice if say, I could make the menu only go to the borders of
the application itself (in this case, not that long).
To limit the menu in the application window, will be difficult. But here
are two ways of automatically limiting the number of entries that can
appear in a menu by specializing the Tkinter Menu class:
--
from Tkinter import *
class LongMenu(Menu):
Automatically creates a cascade entry labelled 'More...' when the
number of entries is above MAX_ENTRIES.
MAX_ENTRIES = 20
def __init__(self, *args, **options):
Menu.__init__(self, *args, **options)
self.nextMenu = None
def add(self, itemType, cnf={}, **kw):
if self.nextMenu is not None:
return self.nextMenu.add(itemType, cnf, **kw)
nbEntries = self.index(END)
if nbEntries LongMenu.MAX_ENTRIES:
return Menu.add(self, itemType, cnf, **kw)
self.nextMenu = LongMenu(self)
Menu.add(self, 'cascade', label='More...', menu=self.nextMenu)
return self.nextMenu.add(itemType, cnf, **kw)
class AutoBreakMenu(Menu):
Automatically adds the 'columnbreak' option on menu entries to make
sure that the menu won't get too high.
MAX_ENTRIES = 20
def add(self, itemType, cnf={}, **kw):
entryIndex = 1 + (self.index(END) or 0)
if entryIndex % AutoBreakMenu.MAX_ENTRIES == 0:
cnf.update(kw)
cnf['columnbreak'] = 1
kw = {}
return Menu.add(self, itemType, cnf, **kw)
if __name__ == '__main__':
root = Tk()
menubar = Menu(root)
def fillMenu(menu):
for i in xrange(100):
menu.add_command(label=str(i), command=root.quit)
menu.add_command(label=Exit, command=root.quit)
menu1 = LongMenu(menubar, tearoff=0)
fillMenu(menu1)
menu2 = AutoBreakMenu(menubar, tearoff=0)
fillMenu(menu2)
menubar.add_cascade(label=Test1, menu=menu1)
menubar.add_cascade(label=Test2, menu=menu2)
root.config(menu=menubar)
root.mainloop()
--
If your application is more complicated than that (e.g if you insert menu
entries after the first adds), you'll have to change the code above a bit,
since it doesn't handle calls to insert at all. But you get the idea.
HTH
--
python -c print ''.join([chr(154 - ord(c)) for c in
'U(17zX(%,5.zmz5(17l8(%,5.Z*(93-965$l7+-'])
Thanks, I'll see what I can do with that.
--
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Re: Why do this?
Do whichever makes you happy I'd say The only real difference is coding style and the formatting options of the %s way that I can see. %s is negligibly slower in my tests, but we're talking the tiniest fraction of a second over thousands of iterations, not worth considering... -h Hari Sekhon Matthew Warren wrote: Ok, not really python focused, but it feels like the people here could explain it for me :) Now, I started programming when I was 8 with BBC Basic. I never took any formal classes however, and I have never become an expert programmer. I'm an average/hobbyist programmer with quite a few languages under my belt but I cant do any really fancy tricks with any of them. (although Python might be nudging me into more advanced things, now I'm starting to get what all the __method__ thingies and operators are all about) 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 hope I'm not being dense. The result is that I have pathalogically avoided print %s % (thing) because it seems to just over complicate things. Ta, :) Matt. This email is confidential and may be privileged. If you are not the intended recipient please notify the sender immediately and delete the email from your computer. You should not copy the email, use it for any purpose or disclose its contents to any other person. Please note that any views or opinions presented in this email may be personal to the author and do not necessarily represent the views or opinions of Digica. It is the responsibility of the recipient to check this email for the presence of viruses. Digica accepts no liability for any damage caused by any virus transmitted by this email. UK: Phoenix House, Colliers Way, Nottingham, NG8 6AT UK Reception Tel: + 44 (0) 115 977 1177 Support Centre: 0845 607 7070 Fax: + 44 (0) 115 977 7000 http://www.digica.com SOUTH AFRICA: Building 3, Parc du Cap, Mispel Road, Bellville, 7535, South Africa Tel: + 27 (0) 21 957 4900 Fax: + 27 (0) 21 948 3135 http://www.digica.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Python/Tkinter crash.
Hendrik van Rooyen wrote: Fredrik Lundh [EMAIL PROTECTED] wrote: Eric Brunel wrote: AFAIK, Tkinter is not thread safe. Using some kind of lock to serialize the calls from different threads may seem to work (I never tested it actually), but the safest way I found to use threads with Tkinter was to call it only from the thread where the main loop executes. the Tkinter binding contains some code that attempts to deal with re- entrant calls, but I don't know/remember to what extent it's actually supposed to work (in other words, if the observed problems are bugs or just limitations). (maybe Martin's memory is better?) anyway, I usually play it safe and make sure to use a single thread to deal with the UI. /F I must be dense - After I have called mainloop, if I have not started another thread to respond to events that are not generated by the user on the screen (in this case values of variables to display from the field generated by different processes - there is other hardware out there), how do I get control back to do the necessary updating? - I suppose I can use the call back after some time thingy to implement a polling loop - possibly as Russel Owen suggested - by polling a queue - but queues are for between threads - and I have seen here somewhere that sockets also want to be the main thread - so that leaves a pipe - and I have had bad experiences with pipes that are unblocked, and if I don't unblock it, then the gui will grind to a haltso I need a thread for the pipe between processes, and a queue between threads, and a time out based polling loop to read the queue, it seems - is it even safe to change a main loop variable from another thread? , or should I do it all via commands through a queue, implementing a whole goddam serial protocol just between threads? and If I don't have another thread to do the timing for the animation bits, then I must base that on a timed callback too, and somehow keep state between callbacks... now is it ok to call widget command methods from a callback in the same thread, or do I have to use invoke? My head is beginning to hurt... - what was a nice simple threaded implementation is turning into a spaghetti monster of timed callbacks - you thought gotos was bad? - you aint seen nothing yet... See if this helps: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/82965 It's Jacob Hallen's description of how he solved the problem. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
RE: Why do this?
[Matthew Warren] | Now, I started programming when I was 8 with BBC Basic. Hey, likewise! (Except I was 12 when it came out!) | 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 perfectly sound Python code, as far as it goes, altho' obviously Print is spelt print in Python, and if that number is in fact a number it'll need to be str ()-ed first. | But nowadays, I see things like this all over the place; | | print(There are %s ways to skin a %s % (number, furryanimal)) The outermost brackets are (at the moment) unnecessary in python, altho' print is slated for replacement by a function in Python 3.0 at which point they'll be necessary. number = 3 animal = cat print There are %d ways to skin a %s % (number, animal) | 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 think what it comes down to is just what's most readable in the situation in which you're using it. Imagine a rather longer string, and one where number and animal are not short names, but calls to some function. Sometimes, since %s will call __str__ on anything it's passed, it's a quick way to get a string representation of a more complex object, which you'd otherwise have to str () at least. | I hope I'm not being dense. Nothing dense about it. Very often a matter of taste and style. Sometimes I find myself using string substitution where a simple string addition might suffice simply because of consistency, for example where it's surrounded by some more complex cases as described above, and I don't want to break the pattern simply because the case is simpler. Also, for me, substitution often reads more naturally because you're not breaking the string up with lots of + + ... + yyy + ... stuff. Again, though, depends on what your code looks like, and how readable you find it. Certainly, I wouldn't advocate *pathologically* avoiding the %s % blah style, but it needn't always be the right thing. A typical example where it can become cumbersome is when you're partially reinventing a templating system with quite a long string, say of HTML, and quite a few substitutions right at the end. It may be easier to use the dictionary form of the substitution then, eg: print Long string with %(valueA)s and %(valueB)s and %(valueC)s embedded in it at some distance from the end... ... % dict (valueA=1, valueB=blah, valueC=datetime.datetime.now ()) Obviously that dict would likely be defined elsewhere, or could even be locals (). Once you get to this stage, though, you might want to start looking at templating toolkits like Cheetah, Genshi or any of the many others knocking around. TJG This e-mail has been scanned for all viruses by Star. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk -- 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 -- http://mail.python.org/mailman/listinfo/python-list
Re: Why do this?
In [EMAIL PROTECTED], 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. For me it's the other way around -- I find the second one more readable especially without syntax highlighting to see which characters are inside and which are outside the quotes. With the second one there's a clear visual separation of the string literal and the variables, even without colors. Another advantage of the second way is much easier localization and other tasks where the sentence itself is not hardcoded but read from files, databases, etc. And the '%s' automatically converts the objects to strings. The equivalent to the second example without string formatting would be:: print 'There are' + str(number) + ' ways to skin a ' + str(furryanimal) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Why do this?
Matthew Warren [EMAIL PROTECTED] wrote: 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. apart from the spurious parentheses you added in the second one, you also missed out this variant: print There are, number, ways to skin a, furryanimal That only works for print though, not for other uses of strings, but it is related to the main reason I use format strings instead of concatenation. The problem I have with your first option is the large number of times I've written: print There are+number+ways to skin a+furryanimal or at least something equivalent to it. If I try to make the same mistake with a format string it jumps out to me as wrong: There are%sways to skin a%s % (number, furryanimal) Also, having a variable of type str called 'number' seems perverse (and probably error prone), so I suspect I might need something like: print There are +str(number)+ ways to skin a +furryanimal but the format string does the conversion for free. The other main reason for preferring format strings is that they make it easier to refactor the code. If you ever want to move the message away from where the formatting is done then it's a lot easier to extract a single string than it is to clean up the concatenation. -- http://mail.python.org/mailman/listinfo/python-list
Testing if an object is a function
If I want to test if an object, x, is an integer, I can call isinstance(x, int). But what do I do if I want to test if x is a function? I can do this: if isinstance(x, type(lambda: None)): ... But it does not seem very elegant to me. Surely there is a simpler way to specify a type object that is the type of a function. -- Claus Tondering -- http://mail.python.org/mailman/listinfo/python-list
Re: Testing if an object is a function
Claus Tondering wrote: But what do I do if I want to test if x is a function? I can do this: if isinstance(x, type(lambda: None)): ... But it does not seem very elegant to me. Surely there is a simpler way to specify a type object that is the type of a function. if callable(x): ... (if you really want a function object, and not anything that's likely to be possible to call, see the types module) /F -- http://mail.python.org/mailman/listinfo/python-list
Re: excepthook doesn't give exact line number
I've tried the sample code you provided but it seems to just hang, it must be doing something but unfortunately it must take too long, by which time a second control-c gives an awful dual traceback message showing the original traceback and the new one from the tbiter() func. I've tried a few variations since yesterday but unfortunately those 2 funcs take too long to run to make a viable solution and the script ends up hanging on an uncaught exception. If anybody has any improvements, suggestions or alternatives for getting the proper line number and traceback message inside an excepthook then I'd be grateful to hear them. -h Hari Sekhon Peter Otten wrote: Hari Sekhon wrote: The problem is that the excepthook gives the line of the topmost called function rather that the actual line that generated the error the way you get it with a normal traceback. A look into the traceback module shows that tracebacks are stored as a linked list. Here's a way to get hold of its tail: def tbiter(tb): while tb is not None: yield tb tb = tb.tb_next def last(items): for item in items: pass return item # example usage def myexcepthook(type, value, tb): tb_tail = last(tbiter(tb)) print tb_tail.tb_lineno Peter -- http://mail.python.org/mailman/listinfo/python-list
RE: Why do this?
| Now, I started programming when I was 8 with BBC Basic. Hey, likewise! (Except I was 12 when it came out!) I think it came out before I was 8, and I started out with print and input. Not sure if that's 'real' programming - I don't think I graduated to ifs and thens and gotos and gosubs for a while.. Uhm, Or was it 'def proc' et al for BBC Basic? Brain holes leaking old stuff out :) | Print There are +number+ ways to skin a +furryanimal perfectly sound Python code, as far as it goes, altho' obviously Print is spelt print in Python, and if that number is in fact a number it'll need to be str ()-ed first. Blame outlook and AutoCaps. If number were a number I would write print There are,number,ways to skin a +furryanimal ..something I like about python, 'cause having been pathalogically avoiding %'s etc.. I have learned to hate going string +str(number)+ string | But nowadays, I see things like this all over the place; | | print(There are %s ways to skin a %s % (number, furryanimal)) The outermost brackets are (at the moment) unnecessary in python, Oops :) altho' print is slated for replacement by a function in Python 3.0 at which point they'll be necessary. ? Why do that, point me at a PEP if required and I'll read it :) number = 3 animal = cat print There are %d ways to skin a %s % (number, animal) | 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 think what it comes down to is just what's most readable in the situation in which you're using it. Imagine a rather longer string, and one where number and animal are not short names, but calls to some function. Sometimes, since %s will call __str__ on anything it's passed, it's a quick way to get a string representation of a more complex object, which you'd otherwise have to str () at least. Also, for me, substitution often reads more naturally because you're not breaking the string up with lots of + + ... + yyy + ... stuff. Again, though, depends on what your code looks like, and how readable you find it. Certainly, I wouldn't advocate *pathologically* avoiding the %s % blah style, but it needn't always be the right thing. I am a big fan of easily human readable meaningful names for things, to the extent that I will quite readily use var or function names ThatCanBeQuiteLongAndExplanatory() For me, it helps retain the readbility say, when breaking up a string with lots of + xxx + etc.. Etc.. + lalala It may be easier to use the dictionary form of the substitution then, eg: print Long string with %(valueA)s and %(valueB)s and %(valueC)s embedded in it at some distance from the end... ... % dict (valueA=1, valueB=blah, valueC=datetime.datetime.now ()) Obviously that dict would likely be defined elsewhere, or could even be locals (). Once you get to this stage, though, you might want to start looking at templating toolkits like Cheetah, Genshi or any of the many others knocking around. That's something I wasn't aware of, and I think I'll try if I find myself going something+dict['thingummy']+ red ones and +dict['colour']+ ones The dict substitution does feel a bit easier to read compared to the concatenation, because of the dict[''] noise. Matt. This email is confidential and may be privileged. If you are not the intended recipient please notify the sender immediately and delete the email from your computer. You should not copy the email, use it for any purpose or disclose its contents to any other person. Please note that any views or opinions presented in this email may be personal to the author and do not necessarily represent the views or opinions of Digica. It is the responsibility of the recipient to check this email for the presence of viruses. Digica accepts no liability for any damage caused by any virus transmitted by this email. UK: Phoenix House, Colliers Way, Nottingham, NG8 6AT UK Reception Tel: + 44 (0) 115 977 1177 Support Centre: 0845 607 7070 Fax: + 44 (0) 115 977 7000 http://www.digica.com SOUTH AFRICA: Building 3, Parc du Cap, Mispel Road, Bellville, 7535, South Africa Tel: + 27 (0) 21 957 4900 Fax: + 27 (0) 21 948 3135 http://www.digica.com -- http://mail.python.org/mailman/listinfo/python-list
Re: A Universe Set
On Wed, 04 Oct 2006 11:00:28 -0400, Leif K-Brooks [EMAIL PROTECTED] wrote: Jorgen Grahn wrote: - infinite xrange()s itertools.count()? Oops! You're right. The itertools documentation even refers to the SML and Haskell languages. And it contains itertools.izip(), another thing on my wish list. I have reasons to be Python 2.2 compatible, so I haven't really looked through the nice things in 2.3 and up (generators are in __future__ in 2.2). Stupid of me to overlook itertools, which I've read about here many times. /Jorgen -- // Jorgen Grahn grahn@Ph'nglui mglw'nafh Cthulhu \X/ snipabacken.dyndns.org R'lyeh wgah'nagl fhtagn! -- http://mail.python.org/mailman/listinfo/python-list
RE: Why do this?
Also, having a variable of type str called 'number' seems perverse (and probably error prone), so I suspect I might need something like: And not something I would normally do, but for hastily written contrived examples I might :) print There are +str(number)+ ways to skin a +furryanimal but the format string does the conversion for free. The other main reason for preferring format strings is that they make it easier to refactor the code. If you ever want to move the message away from where the formatting is done then it's a lot easier to extract a single string than it is to clean up the concatenation. -- This is a benefit of pythons implementation of format strings I hadn't considered, that __str__() is called to get the representation. And something I like about python, althgouh at the moment the __xxx__ methods available and their use is something I'm just getting into This email is confidential and may be privileged. If you are not the intended recipient please notify the sender immediately and delete the email from your computer. You should not copy the email, use it for any purpose or disclose its contents to any other person. Please note that any views or opinions presented in this email may be personal to the author and do not necessarily represent the views or opinions of Digica. It is the responsibility of the recipient to check this email for the presence of viruses. Digica accepts no liability for any damage caused by any virus transmitted by this email. UK: Phoenix House, Colliers Way, Nottingham, NG8 6AT UK Reception Tel: + 44 (0) 115 977 1177 Support Centre: 0845 607 7070 Fax: + 44 (0) 115 977 7000 http://www.digica.com SOUTH AFRICA: Building 3, Parc du Cap, Mispel Road, Bellville, 7535, South Africa Tel: + 27 (0) 21 957 4900 Fax: + 27 (0) 21 948 3135 http://www.digica.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Why do this?
Duncan Booth wrote: print There are+number+ways to skin a+furryanimal or at least something equivalent to it. If I try to make the same mistake with a format string it jumps out to me as wrong: There are%sways to skin a%s % (number, furryanimal) Related to this, formatting with sequences is also much more readable when there are complex interpunction and quoting characters present, like this: print '+var1+','+var2'+,+var3 the above is much more readable as print '%s', '%s', %s % (var1, var2, var3) -- http://mail.python.org/mailman/listinfo/python-list
Re: Testing if an object is a function
Fredrik Lundh wrote: if callable(x): Perfect. Thank you. -- Claus Tondering -- http://mail.python.org/mailman/listinfo/python-list
Re: excepthook doesn't give exact line number
Thanks for the pointer, I've now got this giving me the right line number when an exception occurs, although I still get an empty stack trace from print "Stack Trace:\n%s\n" % str(traceback.print_exc(2)) inside the excepthook. Any ideas why this is? Is there no traceback since the traceback was fed to the excepthook? Is there another way of getting the traceback like you see when the exception isn't caught? Thanks for the help. -h Hari Sekhon Peter Otten wrote: Hari Sekhon wrote: The problem is that the excepthook gives the line of the topmost called function rather that the actual line that generated the error the way you get it with a normal traceback. A look into the traceback module shows that tracebacks are stored as a linked list. Here's a way to get hold of its tail: def tbiter(tb): while tb is not None: yield tb tb = tb.tb_next def last(items): for item in items: pass return item # example usage def myexcepthook(type, value, tb): tb_tail = last(tbiter(tb)) print tb_tail.tb_lineno Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Why do this?
Le jeudi 05 octobre 2006 13:16, Ivan Voras a écrit : print '+var1+','+var2'+,+var3 the above is much more readable as print '%s', '%s', %s % (var1, var2, var3) It feels not IMO, one proof I see is that you forgot the spaces after periods in your first example, and it's even not easy to figure it out... In fact this is a typical case I replace the first by the second, when the string comes a little complex. -- _ Maric Michaud _ Aristote - www.aristote.info 3 place des tapis 69004 Lyon Tel: +33 426 880 097 -- http://mail.python.org/mailman/listinfo/python-list
RE: Why do this?
Duncan Booth wrote: print There are+number+ways to skin a+furryanimal or at least something equivalent to it. If I try to make the same mistake with a format string it jumps out to me as wrong: There are%sways to skin a%s % (number, furryanimal) Related to this, formatting with sequences is also much more readable when there are complex interpunction and quoting characters present, like this: print '+var1+','+var2'+,+var3 the above is much more readable as print '%s', '%s', %s % (var1, var2, var3) Hmm, with my hastily written contrived example, I had forgotten about sequences like that. Oddly, in the case above I prefer reading the bottom example, And shouldn't that top one be print '+var1+','+var2+',+var3 ;) So to conclude, in future I will read it, and see how readable it is before I decide. But now at least I do see a reason not to pathalogically avoid such string formatting :) Matt. This email is confidential and may be privileged. If you are not the intended recipient please notify the sender immediately and delete the email from your computer. You should not copy the email, use it for any purpose or disclose its contents to any other person. Please note that any views or opinions presented in this email may be personal to the author and do not necessarily represent the views or opinions of Digica. It is the responsibility of the recipient to check this email for the presence of viruses. Digica accepts no liability for any damage caused by any virus transmitted by this email. UK: Phoenix House, Colliers Way, Nottingham, NG8 6AT UK Reception Tel: + 44 (0) 115 977 1177 Support Centre: 0845 607 7070 Fax: + 44 (0) 115 977 7000 http://www.digica.com SOUTH AFRICA: Building 3, Parc du Cap, Mispel Road, Bellville, 7535, South Africa Tel: + 27 (0) 21 957 4900 Fax: + 27 (0) 21 948 3135 http://www.digica.com -- http://mail.python.org/mailman/listinfo/python-list
Subclassing built-in classes
I know that python doesn't allow extending built-in objects like the
str class; but you can subclass them using a class of the same name and
thus shadow them to get the same general effect (albeit you have to use
the explicit constructor rather than literals).
class str(str):
def display(self):
print self
str('blah').display()
I was just playing around and realized that assigning to
__builtins__.str (or if you prefer sys.modules['__builtin__'].str) has
the same effect.
class mystr(str):
def display(self):
print self
__builtins__.str = mystr
str('blah').display()
So that made me wonder...couldn't python (in theory) allow for literals
to use extended classes by using the object in __builtins__.class as
the class for literals? By default it would be the standard base class,
but it could also be a custom subclass. Would that be possible / easy /
worthwhile to do?
Regards,
Jordan
--
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RE: Why do this?
[Matthew Warren] | Blame outlook and AutoCaps. If number were a number I would write | | print There are,number,ways to skin a +furryanimal You see now that strikes me as a bit mixed up. Why not simply use? print a, number, c, string | altho' print is slated for replacement by a function in Python 3.0 | at which point they'll be necessary. | | ? Why do that, point me at a PEP if required and I'll read it :) Oft-discussed, and personally I prefer it as a statement, but the edict has gone out. Look at PEP 3100: http://www.python.org/dev/peps/pep-3100/ | That's something I wasn't aware of, and I think I'll try if I find | myself going | | something+dict['thingummy']+ red ones and +dict['colour']+ ones | | The dict substitution does feel a bit easier to read compared to the | concatenation, because of the dict[''] noise. Ultimately it's down to you, but I think you may be doing your code a disservice by so assiduously avoiding the %s-style of string building. Your last example suggests that you see the dict-subtitution flavour simply as an alternative to doing a + dict[key1] + b + dict[key2] etc. I doubt if I've *ever* started with the one and ended with the other; rather I've seen that my code would be more readable if I put/had what I wanted into a dict (or a dict-like object; just has to support __getitem__). An easy example of this is where -- like many, I believe -- I prefer my database rows to come in dict-like objects, rather than the tuples which the dbapi stipulates. Again, like many, I've used or rolled my own wrapper which means I can do things like this, where my dbutils.fetch function returns some kind of object which traps __getitem__ calls for column names and returns the appropriate entry in the underlying tuple: fake code import dbutils db = db_module.connect (...) for row in dbutils.fetch (db, SELECT * FROM blah): print Customer %(name)s (%(id)d) has %(n_orders)d outstanding orders since %(last_order_date)s % row /fake code TJG This e-mail has been scanned for all viruses by Star. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk -- http://mail.python.org/mailman/listinfo/python-list
Re: A Universe Set
On Thu, 05 Oct 2006 00:02:51 +0200, Wildemar Wildenburger [EMAIL PROTECTED]
wrote:
Jorgen Grahn wrote:
Any use cases for these?
- the wildcard object, which compares equal to everything else
Like someone else wrote, for quick-and-dirty comparisons or lists and
dictionaries where I don't care about one part. I think I wanted it for
unittest's assertEqual(foo, bar) at one point.
self.assertEqual(['foo', 42, [], WILDCARD], my_result)
versus
self.assertEqual('foo', my_result[0])
self.assertEqual(42, my_result[1])
self.assertEqual([], my_result[2])
self.assertEqual(4, len(my_result))
# possibly assert that 'my_result' is a list-like
# object too
But I agree that the WILDCARD isn't the kind of object you want to spread
throughout your code; its behaviour is too odd.
- infinite xrange()s
Available in itertools, as someone pointed out.
- the black hole function 'def f(*args): pass'
I often find myself adding logging to functions by passing sys.stderr.write
as an argument to it. Passing blackhole is an elegant and fast way of
disabling logging.
- the identity function 'def f(x): return x'
I don't think I've used it. Maybe if you do a lot of manipulation of
functions and functors -- in some sense it's to function application what 0
is to addition, or 1 to multiplication.
/Jorgen
--
// Jorgen Grahn grahn@Ph'nglui mglw'nafh Cthulhu
\X/ snipabacken.dyndns.org R'lyeh wgah'nagl fhtagn!
--
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Re: dictionary of list from a file
Peter Otten wrote: [EMAIL PROTECTED] wrote: for line in (l.rstrip(\n) for l in file(test.txt, rU) if l[0] != \n): \001\001\001k,\001v\001=\001line.split() \001\001\001d.setdefault(k,\001[]).append(v) Note that this snippet will produce the same output with or without the rstrip() method call. Wow. That's not at all what I expected. I would've thought I'd see: 1.split() ['', '1'] -- http://mail.python.org/mailman/listinfo/python-list
Re: Subclassing built-in classes
MonkeeSage wrote:
I know that python doesn't allow extending built-in objects like the
str class; but you can subclass them using a class of the same name and
thus shadow them to get the same general effect (albeit you have to use
the explicit constructor rather than literals).
class str(str):
def display(self):
print self
str('blah').display()
I was just playing around and realized that assigning to
__builtins__.str (or if you prefer sys.modules['__builtin__'].str) has
the same effect.
class mystr(str):
def display(self):
print self
__builtins__.str = mystr
str('blah').display()
So that made me wonder...couldn't python (in theory) allow for literals
to use extended classes by using the object in __builtins__.class as
the class for literals? By default it would be the standard base class,
but it could also be a custom subclass. Would that be possible / easy /
worthwhile to do?
Unfortunately the literals are interpreted during bytecode generation,
before the compiled program is available, and your modifications to
__builtns__ haven't been made, so the answer is no, I'm afraid.
regards
Steve
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RE: Why do this?
[Matthew Warren] | Blame outlook and AutoCaps. If number were a number I would write | | print There are,number,ways to skin a +furryanimal You see now that strikes me as a bit mixed up. Why not simply use? print a, number, c, string Habit (not always a good thing..), and it helps keep the distinction as to what is a number and what is s a string. Ultimately it's down to you, but I think you may be doing your code a disservice by so assiduously avoiding the %s-style of string building. Your last example suggests that you see the dict-subtitution flavour simply as an alternative to doing a + dict[key1] + b + dict[key2] etc. I doubt if I've *ever* started with the one and ended with the other; rather I've seen that my code would be more readable if I put/had what I wanted into a dict (or a dict-like object; just has to support __getitem__). Not quite. I was meaning that where I had things naturally in a dict and found myself concatenating the string, I would now probably use the substitution method. An easy example of this is where -- like many, I believe -- I prefer my database rows to come in dict-like objects, rather than the tuples which the dbapi stipulates. Again, like many, I've used or rolled my own wrapper which means I can do things like this, where my dbutils.fetch function returns some kind of object which traps __getitem__ calls for column names and returns the appropriate entry in the underlying tuple: fake code import dbutils db = db_module.connect (...) for row in dbutils.fetch (db, SELECT * FROM blah): print Customer %(name)s (%(id)d) has %(n_orders)d outstanding orders since %(last_order_date)s % row /fake code TJG I'm only just really looking into the effects of using things like __getitem__ etc.., I imagine my approach will become more sophisticated once I have looked into them. This email is confidential and may be privileged. If you are not the intended recipient please notify the sender immediately and delete the email from your computer. You should not copy the email, use it for any purpose or disclose its contents to any other person. Please note that any views or opinions presented in this email may be personal to the author and do not necessarily represent the views or opinions of Digica. It is the responsibility of the recipient to check this email for the presence of viruses. Digica accepts no liability for any damage caused by any virus transmitted by this email. UK: Phoenix House, Colliers Way, Nottingham, NG8 6AT UK Reception Tel: + 44 (0) 115 977 1177 Support Centre: 0845 607 7070 Fax: + 44 (0) 115 977 7000 http://www.digica.com SOUTH AFRICA: Building 3, Parc du Cap, Mispel Road, Bellville, 7535, South Africa Tel: + 27 (0) 21 957 4900 Fax: + 27 (0) 21 948 3135 http://www.digica.com -- http://mail.python.org/mailman/listinfo/python-list
Asychronous execution *with* return codes?
I hope I have not overlooked a solution already posted, but I seem to be unable to suss out a way to achieve both multiple console-less executions of a given (console) application and gathering the return code from the application. What I have found: code import subprocess # gives back return code, but does not run asynchronously retcode = subprocess.call([app, lstArgs]) retcode = subprocess.Popen([app] + lstArgs).wait() # runs the app async, but only returns the pid (no return code) pid = subprocess.Popen([app] + lstArgs).pid /code Is there some magic elixir which will get me both? TIA -- http://mail.python.org/mailman/listinfo/python-list
Re: Subclassing built-in classes
Steve Holden wrote: Unfortunately the literals are interpreted during bytecode generation, before the compiled program is available, and your modifications to __builtns__ haven't been made, so the answer is no, I'm afraid. Ah! That makes sense. I guess the only way to do it would be to add an extra bit to every object to indicate whether it was constructed literally and then re-initialize the object after compilation if that bit is set. For some reason I just don't think that's gonna happen. ;) Thanks for taking the time to explain. Regards, Jordan -- http://mail.python.org/mailman/listinfo/python-list
Re: Subclassing built-in classes
Le jeudi 05 octobre 2006 14:20, Steve Holden a écrit : Unfortunately the literals are interpreted during bytecode generation, before the compiled program is available, and your modifications to __builtns__ haven't been made, so the answer is no, I'm afraid. But what prevents to interpret literals as a call to __builtins__ objects and functions ? optimization ? what else ? -- _ Maric Michaud _ Aristote - www.aristote.info 3 place des tapis 69004 Lyon Tel: +33 426 880 097 -- http://mail.python.org/mailman/listinfo/python-list
Re: Asychronous execution *with* return codes?
utabintarbo wrote: pid = subprocess.Popen([app] + lstArgs).pid Check out the poll() method and the returncode attribute: http://docs.python.org/lib/node533.html Regards, Jordan -- http://mail.python.org/mailman/listinfo/python-list
Re: embedding python -- windows specify problems
Hi Fredrik,
Thanks very much for that reply. Your suggestion sounds feasible, I
guess. Taking what you said, and thinking about how I could avoid adding
an additional intepreter step, I thought that I could try the following:
pyfile = PyFile_FromString(name,r);
if(pyfile==NULL){
return 1;
}
f = PyFile_AsFile(pyfile);
PyRun_AnyFileEx(f,name,1);
This seems to work on Linux at least (I'll test it tomorrow on my
Windows machine), and presumably it will work around the problem you
mentioned?
Cheers
JP
Fredrik Lundh wrote:
John Pye wrote:
I have been working on some new code that embeds python in an C
application. The embedding is working fine under Linux but crashing
under Windows (XP) when I reach the following step.
PyRun_AnyFile(f,name);
If there's some python exception being thrown by the PyRun_AnyFile call,
how can I retrieve it from C?
Even when the file (f) being run by Python contains only a 'print'
statement, the application still crashes on WinXP.
the contents and the layout of the FILE structure isn't defined, so
PyRun_AnyFile()
only works if you make sure to open the file using *exactly* the same run
time library
as Python itself uses.
it's usually easier to hand the problem over to the interpreter:
PyRun_SimpleString(execfile('myscript.py')\n);
the same approach can be used to implement custom error handling,
stdout/stderr
redirects, etc.
/F
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RE: dictionary of list from a file
- Python 2.5 introduced a dictionary type with automatic
creation of values,
ala Perl:
===
from collections import defaultdict
d = defaultdict(list)
for line in fl:
k, v = line.strip().split()
d[k].append(v)
for k,v in d.items():
print k, v
===
Notice that Python is always more strongly typed, so you have
to specify a
factory function.
Yay! Python2.5 fixed my approach to this, I tried
from collections import defaultdict
f=file('c:\\test.txt')
lines=f.readlines()
f.close()
d=defaultdict(list)
[ d[l.split()[0]].append(l.split()[1]) for l in lines ]
But, if I try your (to see if I've actually got it right)
For k,v in d.items():
print k,v
I get
AttributeError: 'list' object has no attribute 'items'
Okok, I'm silly.
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It is the responsibility of the recipient to check this email for the presence
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RE: dictionary of list from a file
-Original Message-
From:
[EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]
rg] On Behalf Of Giovanni Bajo
Sent: 04 October 2006 15:17
To: python-list@python.org
Subject: Re: dictionary of list from a file
[EMAIL PROTECTED] wrote:
while(IN){
@info=split(/ +/,$_);
push (@{$tmp{$info[0]}},$info[1]);
}
and then
foreach $key (keys %tmp){
print $key - @{$tmp{$key}}\n;
}
Python 2.5 introduced a dictionary type with automatic
creation of values,
ala Perl:
===
from collections import defaultdict
d = defaultdict(list)
for line in fl:
k, v = line.strip().split()
d[k].append(v)
for k,v in d.items():
print k, v
===
Notice that Python is always more strongly typed, so you have
to specify a
factory function.
Yay! Python2.5 fixed my approach to this, I tried
from collections import defaultdict
f=file('c:\\test.txt')
lines=f.readlines()
f.close()
d=defaultdict(list)
[ d[l.split()[0]].append(l.split()[1]) for l in lines ]
But, if I try your (to see if I've actually got it right)
For k,v in d.items():
print k,v
I get
AttributeError: 'list' object has no attribute 'items'
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computer.
You should not copy the email, use it for any purpose or disclose its contents
to any other person.
Please note that any views or opinions presented in this email may be personal
to the author and do not necessarily represent the views or opinions of Digica.
It is the responsibility of the recipient to check this email for the presence
of viruses. Digica accepts no liability for any damage caused by any virus
transmitted by this email.
UK: Phoenix House, Colliers Way, Nottingham, NG8 6AT UK
Reception Tel: + 44 (0) 115 977 1177
Support Centre: 0845 607 7070
Fax: + 44 (0) 115 977 7000
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SOUTH AFRICA: Building 3, Parc du Cap, Mispel Road, Bellville, 7535, South
Africa
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Re: can't open chm files all of a sudden
Dennis Lee Bieber wrote: On Wed, 04 Oct 2006 22:36:10 -0400, John Salerno [EMAIL PROTECTED] declaimed the following in comp.lang.python: John Machin wrote: 4. Have you done a full virus and spy-ware scan? Do you regularly install Windows updates from Microsoft? Well, this is certainly the last thing I expected to work, but it did! There was something called an IECache cookie (which I've actually had before) and after removing it my chm files open now! Thanks for suggesting this! I was desperate! :) Probably some stray left behind by HTML KIt G... Remember, the rendering engine is NOT Internet Explorer only, it is shared by the desktop file Explorer, the help viewer, etc LOL. I was also asking for help in the HTML Kit newsgroup, and of course they assured me that HTML Kit does not change chm settings or replace dlls, nor is it related to this piece of spyware. :) -- http://mail.python.org/mailman/listinfo/python-list
Re: Subclassing built-in classes
Maric Michaud wrote: Le jeudi 05 octobre 2006 14:20, Steve Holden a écrit : Unfortunately the literals are interpreted during bytecode generation, before the compiled program is available, and your modifications to __builtns__ haven't been made, so the answer is no, I'm afraid. But what prevents to interpret literals as a call to __builtins__ objects and functions ? optimization ? what else ? How can you modify __builtins__ before your program starts running? You can't. What does the interpreter have to do before the program runs? Translate it into bytecode. When are literals interpreted? During translation into bytecode. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
Re: socket client server... simple example... not working...
Jean-Paul Calderone wrote:
On 4 Oct 2006 19:31:38 -0700, SpreadTooThin [EMAIL PROTECTED] wrote:
client:
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((192.168.1.101, 8080))
print 'Connected'
s.send('ABCD')
Here you didn't check the return value of send to determine if all of the
string was copied to the kernel buffer to be sent, so you may have only
succeeded in sending part of 'ABCD'.
buffer = s.recv(4)
in the above call, 4 is the maximum number of bytes recv will return. It
looks as though you are expecting it to return exactly 4 bytes, but in order
to get that, you will need to check the length of the return value and call
recv again with a lower limit until the combination of the return values of
each call gives a total length of 4.
print buffer
s.send('exit')
Again, you didn't check the return value of send.
server:
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.bind((192.168.1.101, 8080))
serversocket.listen(5)
print 'Listen'
(clientsocket, address) = serversocket.accept()
print 'Accepted'
flag = True
while flag:
chunk = serversocket.recv(4)
You're calling recv on serversocket instead of on clientsocket. You're also
relying on recv to return exactly 4 bytes, which it may not do.
if chunk == '':
raise RuntimeError, socket connection broken
elif chunk == 'exit':
flag = False
else:
serversocket.send(chunk)
Another missing check of the return value of send.
print 'Done'
Server says!
Listen
Accepted
Traceback (most recent call last):
File server.py, line 11, in ?
chunk = serversocket.recv(4)
socket.error: (57, 'Socket is not connected')
Client says:
Connected
What have I done wrong now!
I recommend switching to Twisted. The Twisted equivalent (I guess - the
protocol defined above is strange and complex (probably unintentionally, due
to the things you left out, like any form of delimiter) and I doubt I really
understand the end goal you are working towards), minus bugs (untested):
# client.py
from twisted.internet import reactor, protocol
class Client(protocol.Protocol):
buf = ''
def connectionMade(self):
self.transport.write('ABCD')
def dataReceived(self, data):
self.buf += data
if len(self.buf) = 4:
reactor.stop()
protocol.ClientCreator(reactor, Client).connectTCP('192.168.1.101', 8080)
reactor.run()
# server.py
from twisted.internet import reactor, protocol
class Server(protocol.Protocol):
buf = ''
def dataReceived(self, bytes):
self.buf += bytes
exit = self.buf.find('exit')
if exit != -1:
self.transport.write(self.buf[:exit])
self.buf = self.buf[exit + 4:]
reactor.stop()
else:
self.transport.write(self.buf)
self.buf = ''
f = protocol.ServerFactory()
f.protocol = Server
reactor.listenTCP('192.168.1.101', 8080, f)
reactor.run()
Hope this helps,
Jean-Paul
Jean-Paul many thanks for this and your effort.
but why is it every time I try to do something with 'stock' python I
need another package?
By the time I've finished my project there are like 5 3rd party add-ons
to be installed.
I know I'm a python newbie... but I'm far from a developer newbie and
that can be a recipe for
disaster. The stock socket should work and I think I've missed an
obvious bug in the code other
than checking the return status.
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Re: Python to use a non open source bug tracker?
Ben This thread was started on the shock of realising that a non-free Ben tool was even being *considered* for the new Python bug Ben tracker. Those are the terms on which I've been arguing. Of course, the candidate trackers have been known for months. Messages have been posted to both this list and python-dev asking for inputs. Skip -- http://mail.python.org/mailman/listinfo/python-list
How do I read Excel file in Python?
How do I read an Excel file in Python? I have found a package to read excel file, which can be used on any platform. http://www.lexicon.net/sjmachin/xlrd.htm I installed and working on the examples, I found its printing of cell's contents in a different manner. import xlrd book=xlrd.open_workbook(Calculation_file.xls) book=xlrd.open_workbook(testbook.xls) sh=book.sheet_by_index(0) for row in range(sh.nrows): print sh.row(rx) [text:u'name', text:u'address', text:u'ph'] [text:u'sudhir', text:u'bangalore', number:1234.0] [text:u'vinay', text:u'bangalore', number:3264.0] I am bit confused with slicing. help me Thank you, Regards, Sudhir. -- http://mail.python.org/mailman/listinfo/python-list
Getting a ValueError with comtypes
Hello,
I am working with comtypes to interface Microsoft's DirectShow library.
First, I found a Type Library on the internet that was created for
accessing DirectShow from .NET. It seems that DirectShow only comes
with IDL files and no type library.
This got me started.
The following line imports the typelibrary and automatically generates
a wrapper module for DirectShow.
ds = comtypes.client.GetModule('DirectShow.tlb')
Next, I can basically start with something like this:
graph = comtypes.CoCreateInstance(CLSID_FilterGraph, ds.IGraphBuilder,
comtypes.CLSCTX_INPROC_SERVER)
I had to create the CLSID_FilterGraph parameter myself by doing the
following:
CLSID_FilterGraph =
comtypes.GUID('{e436ebb3-524f-11ce-9f53-0020af0ba770}')
One of the first issues I ran into was that the type library I found on
the web didn't expose the IMediaControl interface. So, using the
generated wrapper as a template, I created my own wrapper:
class IMediaControl(comtypes.IUnknown):
_case_insensitive_ = True
_iid_ = comtypes.GUID('{56A868B1-0AD4-11CE-B03A-0020AF0BA770}')
_idlflags_ = []
IMediaControl._methods_ = [
COMMETHOD([], HRESULT, 'Run'),
COMMETHOD([], HRESULT, 'Pause'),
COMMETHOD([], HRESULT, 'Stop'),
COMMETHOD([], HRESULT, 'StopWhenReady'),
COMMETHOD([], HRESULT, 'GetState',
(['in'], c_long, 'msTimeout'),
(['out'], POINTER(c_int), 'pfs' ))
]
This got me further. Once I defined the interface, I get access to the
interface by calling:
control = graph.QueryInterface(IMediaControl)
This seemed to work. Once I got everything setup, I tried to use this
interface. For example:
control.Run()
This generates an exception:
Traceback (most recent call last):
File stdin, line 1, in ?
File ds.py, line 462, in play
control.Run()
ValueError: Procedure probably called with not enough arguments (4
bytes missing)
You can get errors like this when using ctypes if you use the wrong
calling convention (CDLL versus WINDLL).
The method Run on the IMediaControl interface doesn't take any
arguments.
I did notice that some wrapper code uses STDMETHOD versus COMMETHOD,
but changing this didn't make any difference.
Can anyone explain what might be happening here, or offer some
suggestions?
Thanks in advance,
Jeff
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Re: Asychronous execution *with* return codes?
MonkeeSage wrote: utabintarbo wrote: pid = subprocess.Popen([app] + lstArgs).pid Check out the poll() method and the returncode attribute: http://docs.python.org/lib/node533.html Thanks for the reply. If I understand your meaning, I should do something like this (given I wish to run an app against several arguments [my use case]): for lstArgs in pileOflstArgs: uniqueProcessID = subprocess.Popen([app] + lstArgs) pid = uniqueProcessID.pid retcode = uniqueProcessID.poll() # increment uniqueProcessID If so, how do I handle the poll() on long-running processes? Run a bunch and then start a check loop? Am I asking too many questions? -- http://mail.python.org/mailman/listinfo/python-list
Re: What value should be passed to make a function use the default argument value?
On 2006-10-04, Fredrik Lundh [EMAIL PROTECTED] wrote: Georg Brandl wrote: This is an issue in most Python documentation: you're not told if the described function is implemented in C, and if it is keyword arg-enabled. The arguments must be given names though, to be able to document them. the general rule is that if the documentation doesn't explicitly say that something is a keyword argument, it isn't, and shouldn't be treated as such. The first module I looked in to check this, it wasn't true. In the Queue Module is isn't explicitly written that maxsize is a keyword argument yet Queue.Queue(maxsize=9) works just fine. I then took a look in the Threading module and found that the semaphore documentation didn't mention anything about keyword arguments but again they worked fine. It wouldn't surprise me if this was true for the complete threading documentation. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: socket client server... simple example... not working...
On 5 Oct 2006 07:01:50 -0700, SpreadTooThin [EMAIL PROTECTED] wrote: [snip] Jean-Paul many thanks for this and your effort. but why is it every time I try to do something with 'stock' python I need another package? Maybe you are trying to do things that are too complex :) By the time I've finished my project there are like 5 3rd party add-ons to be installed. I don't generally find this to be problematic. I know I'm a python newbie... but I'm far from a developer newbie and that can be a recipe for disaster. Not every library can be part of the standard library, neither can the standard library satisfy every possible use-case. Relying on 3rd party modules isn't a bad thing. The stock socket should work and I think I've missed an obvious bug in the code other than checking the return status. Well, I did mention one bug other than failure to check return values. Maybe you missed it, since it was in the middle. Go back and re-read my response. Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Subclassing built-in classes
Le jeudi 05 octobre 2006 15:52, Steve Holden a écrit :
But what prevents to interpret literals as a call to __builtins__ objects
and functions ? optimization ? what else ?
When are literals interpreted? During translation into bytecode.
agreed, but what's the problem with this ?
We can actually monkey patch all buitins like in this example :
In [1]: oldstr=str
In [2]: class mystr(str) :
...: def __new__(*a, **kw) :
...: print 'called : ', a, kw
...: return oldstr.__new__(*a, **kw)
...:
...:
In [3]: import __builtin__
In [4]: __builtin__.str = mystr
called : (class '__main__.mystr', ItplNS 'In
[${self.cache.prompt_count}]: ' ) {}
called : (class '__main__.mystr', 5) {}
...
If the generated bytecode of {k:v} is more or less the same as the one
gernerated by dict(((k,v))), monkey patching dict will work for dict literals
too.
Also, this should work with scalars, 'a string' be translated in what
actually is produced by str('a string') (of course the internal code for
building scalars should still be there).
If that is feasible without big refactoring and do not introduce noticeable
performance loss is what I don't know, but it could be a nice feature of
__builtin__ module IMO (at less I expected it to work like this when I first
tried it).
--
_
Maric Michaud
_
Aristote - www.aristote.info
3 place des tapis
69004 Lyon
Tel: +33 426 880 097
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building strings from variables
Following a discussion with an associate at work about various ways to build strings from variables in python, I'd like to hear your opinions and preferred methods. The methods we discussed are: 1. some_string = cd %s ; %s %d %s %s % ( working_dir, ssh_cmd, some_count, some_param1, some_param2) 2. import string template = string.Template(cd $dir ; $cmd $count $param1 $param2) some_string = template.substitute(dict(dir=working_dir, cmd=ssh_cmd, count=some_count, pararm1=some_param1, param2=some_param2)) here you can use a couple of nice tricks by using class.__dict__ and globals() \ locals() dictionaries. 3. some_string = cd +working_dir+ ; +ssh_cmd+ +str(some_count)+ +some_param1+ +some_param2 (all these are supposed to produce the same strings) Which methods do you know of \ prefer \ think is better because...? I will appreciate any opinions about the matter. -- http://mail.python.org/mailman/listinfo/python-list
Oracle database export
Hi, I need to export an Oracle database to a DDL-formated file. On the Web, I found a Python script that did exactly this for a MS Access database, but not one for Oracle databases. Does anyone know of such a tool or Python script. regards tores -- http://mail.python.org/mailman/listinfo/python-list
Restoring override of urllib.URLopener.open_https
Hi, the M2Crypto library overrides the urllib.URLopener.open_https method, causing a urllib.urlopen to a https: server to fail in my case. My python is not that strong, so is there a way to set urllib.URLopener.open_https back to the original code? I prefer not to modify M2Crypto. Thanks, Arno Bakker -- http://mail.python.org/mailman/listinfo/python-list
Re: Access to static members from inside a method decorator?
Bruno Desthuilliers wrote:
[EMAIL PROTECTED] wrote:
I'm developing a library at the moment that involves many classes, some
of which have exposed capabilities. I'm trying to design a nice
interface for both exposing those capabilities, and inspecting
instances to find out what capabilities they have.
At the moment, I'm leaning towards a superclass (Exposed) that defines
a static method which is a decorator (expose) such that any derived
class can mark a method with @Exposed.expose and it will then be later
returned by getExposedMethods(), a la:
class Exposed:
@staticmethod
def expose( f ):
...
def getExposedMethods( self ):
...
class Person( Exposed ):
@Exposed.expose
def talk( self, ... ):
...
I'm trying to implement the decorator by having it populate a static
member list of whatever class it's in with a reference to the method.
getExposedMethods() would then return the contents of each of those
lists from itself back to Exposed in the class hierarchy. The first
problem was that having a reference to the method (i.e. talk()) does
not allow you to get a reference to the enclosing class (I had hoped
im_class would lead me there).
Not yet. When your decorator is called, the class object is not yet
created, and what you are decorating is a plain function.
The real hiccup was that explicitly
passing the class as an argument to the decorator generates a undefined
global name error, presumably because at that point of execution the
class object hasn't been fully created/initialised.
Exactly.
So how can this be done?
The simplest thing is to use a two-stages scheme : mark the functions as
exposed, then collect them:
def expose(func):
func._exposed = True
return func
def exposed(obj):
return callable(obj) and getattr(obj, '_exposed', False)
class Exposing(object):
@classmethod
def get_exposed_methods(cls):
try:
exposeds = cls._exposed_methods
except AttributeError:
exposeds = []
for name in dir(cls):
obj = getattr(cls, name)
if exposed(obj):
exposeds.append(obj)
cls._exposed_methods = exposeds
return exposeds
class Parrot(Exposing):
@expose
def parrot(self, what):
return %s says %s % (self, str(what))
HTH
--
bruno desthuilliers
python -c print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in '[EMAIL PROTECTED]'.split('@')])
Thanks Bruno. I came up with a similar solution today at work, which
involves an 'init' method which is called at the bottom of each module
that defines subclasses of Exposed and sets up static mappings for the
exposed methods. I guess my solution is slightly less elegant because
it requires this ugly explicit init call outside the classes that it
actually deals with, however it is more efficient because the dir()
pass happens once on module load, instead of every time I want the list
of exposed methods.
Thanks for the help though,
Glen
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Re: MySQLdb for Python 2.5
Martin v. Löwis wrote: Harold Trammel schrieb: Does anyone know the status of a version of MySQLdb that will work with Python 2.5? AFAICT, MySQLdb 1.2.1 builds and works just fine. Regards, Martin Hi Martin, What is your setup as I am receiving a number of Cannot open ... errors related to various msysql libraries and includes? I am running in a Windows XP environment with MySQL 5.1. Thanks in advance. Harold -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I read Excel file in Python?
kath wrote:
How do I read an Excel file in Python?
I have found a package to read excel file, which can be used on any
platform.
Hi Sudhir,
So far, so good :-)
http://www.lexicon.net/sjmachin/xlrd.htm
I installed and working on the examples, I found its printing of cell's
contents in a different manner.
import xlrd
book=xlrd.open_workbook(Calculation_file.xls)
book=xlrd.open_workbook(testbook.xls)
sh=book.sheet_by_index(0)
for row in range(sh.nrows):
print sh.row(rx)
[text:u'name', text:u'address', text:u'ph']
[text:u'sudhir', text:u'bangalore', number:1234.0]
[text:u'vinay', text:u'bangalore', number:3264.0]
It helps when asking questions if you copy/paste exactly what is on
your screen;
in this case
print sh.row(rx)
would have given an error; you must have typed
for rx in range.
A row is returned as a sequence of Cell objects. What you are seeing is
Python automatically doing repr(cell) on each cell in the row. The
Cell.__repr__ method formats it that way for debugging. Here are some
examples from a little test file of mine:
import xlrd
bk = xlrd.open_workbook('sjm1.xls')
sh = bk.sheet_by_index(0)
row0 = sh.row(0)
row0
[text:u'fubar', number:1.0, number:2.0]
firstcell = row0[0]
type(firstcell)
class 'xlrd.sheet.Cell'
firstcell.ctype
1
# cell type 1 is text
firstcell.value
u'fubar'
repr(firstcell)
text:u'fubar'
I am bit confused with slicing. help me
None of the above is anything to do with slicing; is this a 2nd
problem?
Perhaps you are having trouble with this:
help(sh.row_slice)
Help on method row_slice in module xlrd.sheet:
row_slice(self, rowx, start_colx=0, end_colx=None) method of
xlrd.sheet.Sheet instance
##
# Returns a slice of the Cell objects in the given row.
sh.row_slice(rowx, lo, hi) gives the same result as sh.row(rowx)[lo:hi]
-- it is provided because the latter would be inefficient for getting a
small slice from a long row.
If you are having trouble with the general concept of slicing, perhaps
you might like to try the Python tutorial. Otherwise, please try to be
a bit more specific about what the confusion is.
HTH, and e-mail me if you prefer ...
Cheers,
John
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Re: Getting a ValueError with comtypes
[EMAIL PROTECTED] schrieb:
Hello,
I am working with comtypes to interface Microsoft's DirectShow library.
Cool, another one using comtypes!
First, I found a Type Library on the internet that was created for
accessing DirectShow from .NET. It seems that DirectShow only comes
with IDL files and no type library.
What I sometimes do is to compile the IDL files into a typelib just
for creating the comtypes interface wrappers. This may be somewhat
dangerous because these typelibs should *not* be registered by accident,
so that they do not conflict with other typelibs.
Then, I found out with oleview that on my system the IMediaControl interface
is described in the 'ActiveMovie control type library (Ver 1.0)',
in c:\windows\system32\quartz.dll. So I was able to create the wrapper
by calling comtypes.client.GetModule(quartz.dll) - it seems that windows
searches the $PATH to find type libraries.
This got me started.
The following line imports the typelibrary and automatically generates
a wrapper module for DirectShow.
ds = comtypes.client.GetModule('DirectShow.tlb')
Next, I can basically start with something like this:
graph = comtypes.CoCreateInstance(CLSID_FilterGraph, ds.IGraphBuilder,
comtypes.CLSCTX_INPROC_SERVER)
I had to create the CLSID_FilterGraph parameter myself by doing the
following:
CLSID_FilterGraph =
comtypes.GUID('{e436ebb3-524f-11ce-9f53-0020af0ba770}')
One of the first issues I ran into was that the type library I found on
the web didn't expose the IMediaControl interface. So, using the
generated wrapper as a template, I created my own wrapper:
class IMediaControl(comtypes.IUnknown):
_case_insensitive_ = True
_iid_ = comtypes.GUID('{56A868B1-0AD4-11CE-B03A-0020AF0BA770}')
_idlflags_ = []
IMediaControl._methods_ = [
COMMETHOD([], HRESULT, 'Run'),
COMMETHOD([], HRESULT, 'Pause'),
COMMETHOD([], HRESULT, 'Stop'),
COMMETHOD([], HRESULT, 'StopWhenReady'),
COMMETHOD([], HRESULT, 'GetState',
(['in'], c_long, 'msTimeout'),
(['out'], POINTER(c_int), 'pfs' ))
]
This got me further. Once I defined the interface, I get access to the
interface by calling:
control = graph.QueryInterface(IMediaControl)
This seemed to work. Once I got everything setup, I tried to use this
interface. For example:
control.Run()
This generates an exception:
Traceback (most recent call last):
File stdin, line 1, in ?
File ds.py, line 462, in play
control.Run()
ValueError: Procedure probably called with not enough arguments (4
bytes missing)
You can get errors like this when using ctypes if you use the wrong
calling convention (CDLL versus WINDLL).
The method Run on the IMediaControl interface doesn't take any
arguments.
I did notice that some wrapper code uses STDMETHOD versus COMMETHOD,
but changing this didn't make any difference.
Can anyone explain what might be happening here, or offer some
suggestions?
Your mistake here is that IMediaControl derives from IDispatch, not IUnknown.
So, control.Run() really calls the first IDispatch method, which is
GetTypeInfoCount(), which takes one argument ;-).
I'm not 100% sure the following code will work for you because I'm using
a comtypes version that's not yet committed to the repository, but it works
for me:
from comtypes.client import GetModule, CreateObject
# create and import the interface wrapper
ds = GetModule(quartz.dll)
# FilgraphManager is what the wrapper shows as coclass,
# you can pass that to CreateObject instead of a CLSID or ProgID.
# CreateObject calls QueryInterface for the 'most useful' interface,
# so usually there's no need to specify the interface you want:
fg = CreateObject(ds.FilgraphManager)
# this prints '0'
print fg.Run()
Thomas
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Re: Access to static members from inside a method decorator?
Le jeudi 05 octobre 2006 17:18, [EMAIL PROTECTED] a écrit : I guess my solution is slightly less elegant because it requires this ugly explicit init call outside the classes that it actually deals with, however it is more efficient because the dir() pass happens once on module load, instead of every time I want the list of exposed methods. You can always replace the need of the init method on classes using a metaclass. This demonstrates it with Bruno's expose decorator, but it can be done with your actual init func too. In [6]: class m(type) : ...: def __init__(self, *a,**kw) : ...: for name, meth in self.__dict__.items() : ...: if getattr(meth, '_exposed', False) : ...: print 'exposed :', name ...: ...: In [7]: class a(object): ...: __metaclass__ = m ...: def f(self) :pass ...: @expose ...: def g(self) :pass ...: ...: exposed : g In [8]: class b(a) : ...: @expose ...: def h(self) :pass ...: ...: exposed : h -- _ Maric Michaud _ Aristote - www.aristote.info 3 place des tapis 69004 Lyon Tel: +33 426 880 097 -- http://mail.python.org/mailman/listinfo/python-list
RE: building strings from variables
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] rg] On Behalf Of Gal Diskin Sent: 05 October 2006 16:01 To: python-list@python.org Subject: building strings from variables Following a discussion with an associate at work about various ways to build strings from variables in python, I'd like to hear your opinions and preferred methods. The methods we discussed are: 1. some_string = cd %s ; %s %d %s %s % ( working_dir, ssh_cmd, some_count, some_param1, some_param2) 2. import string template = string.Template(cd $dir ; $cmd $count $param1 $param2) some_string = template.substitute(dict(dir=working_dir, cmd=ssh_cmd, count=some_count, pararm1=some_param1, param2=some_param2)) here you can use a couple of nice tricks by using class.__dict__ and globals() \ locals() dictionaries. 3. some_string = cd +working_dir+ ; +ssh_cmd+ +str(some_count)+ +some_param1+ +some_param2 (all these are supposed to produce the same strings) Which methods do you know of \ prefer \ think is better because...? I will appreciate any opinions about the matter. :D I think, it would depend really on what your aims are (readable code, fast string generation...), and how the vars you want to build the string from are respresented in your code (is it natural to use a dict etc..) I kicked off a conversation similar to this earlier today, and that was my conclusion after helpful debate advice. Matt. This email is confidential and may be privileged. If you are not the intended recipient please notify the sender immediately and delete the email from your computer. You should not copy the email, use it for any purpose or disclose its contents to any other person. Please note that any views or opinions presented in this email may be personal to the author and do not necessarily represent the views or opinions of Digica. It is the responsibility of the recipient to check this email for the presence of viruses. Digica accepts no liability for any damage caused by any virus transmitted by this email. UK: Phoenix House, Colliers Way, Nottingham, NG8 6AT UK Reception Tel: + 44 (0) 115 977 1177 Support Centre: 0845 607 7070 Fax: + 44 (0) 115 977 7000 http://www.digica.com SOUTH AFRICA: Building 3, Parc du Cap, Mispel Road, Bellville, 7535, South Africa Tel: + 27 (0) 21 957 4900 Fax: + 27 (0) 21 948 3135 http://www.digica.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Asychronous execution *with* return codes?
If you're on a POSIX system, you could use the usual fork/exec/wait: import os for lstArgs in pileOflstArgs: pid = os.fork() if not pid: os.execv( app, lstArgs ) for i in range(len(pileOflstArgs)): pid, status = os.wait() Of couse, os.wait() will block until a child exits. Look at the docs for the status code it returns, though, as it's not just the return value of the process. On Oct 5, 7:43 am, utabintarbo [EMAIL PROTECTED] wrote: MonkeeSage wrote: utabintarbo wrote: pid = subprocess.Popen([app] + lstArgs).pid Check out the poll() method and the returncode attribute: http://docs.python.org/lib/node533.htmlThanks for the reply. If I understand your meaning, I should do something like this (given I wish to run an app against several arguments [my use case]): for lstArgs in pileOflstArgs: uniqueProcessID = subprocess.Popen([app] + lstArgs) pid = uniqueProcessID.pid retcode = uniqueProcessID.poll() # increment uniqueProcessID If so, how do I handle the poll() on long-running processes? Run a bunch and then start a check loop? Am I asking too many questions? -- http://mail.python.org/mailman/listinfo/python-list
Re: user modules
Cameron Walsh wrote:
Hi,
I'm writing a python program to analyse and export volumetric data. To
make development and extension easier, and to make it more useful to the
public when it is released (LGPL), I would like to enable users to place
their own python files in a user_extensions directory. These files
would implement a common interface in order for the main program to be
able to read them and execute the necessary code.
My question is what is the best way of implementing this?
I have investigated importing them as modules, but unless the user
modifies the main program I cannot see how the main program can learn of
the existence of specific modules.
For example:
from user_modules import *
# directory 'user_modules' contains __init__.py allowing this
# From here I would need a list of the imported modules, in order to
# execute a common command on each of them, such as
for module in imported_modules:
module.initialise()
module.get_tab_window()
How do I get from the first bit to the second bit, or is there a better
way of obtaining the functionality I need?
--Cameron.
import os
files=os.listdir('user_modules')
tabs=[]
for fle in files:
if fle.endswith('.py'):
module=__import__(fle[0:-3], 'user_modules', None,
['initialise', 'get_tab_window'])
module.initialise()
tabs.append(module.get_tab_window())
*not tested*
print __import__.__doc__
__import__(name, globals, locals, fromlist) - module
Import a module. The globals are only used to determine the context;
they are not modified. The locals are currently unused. The fromlist
should be a list of names to emulate ``from name import ...'', or an
empty list to emulate ``import name''.
When importing a module from a package, note that __import__('A.B', ...)
returns package A when fromlist is empty, but its submodule B when
fromlist is not empty.
Tuomas
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Re: Why do this?
Matthew Warren [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] 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 In python: IDLE 1.1.3 number = 3 furryanimal = 'rat' print 'There are', number, 'of ways to skin a', furryanimal There are 3 of ways to skin a rat You have to remember that spaces are added automatically. Printing a comma list is quite common in informal and preliminary work and sometimes in finished work when its output is good enough. But nowadays, I see things like this all over the place; print(There are %s ways to skin a %s % (number, furryanimal)) This gives more control over exact format of output. Some people may also prefer having variables grouped together at end, especially if they 'grew up' on C (for instance) rather than Basic. Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
