Re: What's an elegant way to test for list index existing?
i have a approach, it may not be best
fld = [ ]
for data in shlex.split(ln):
fld.append(data)
On Sat, 29 Sep 2018 at 07:52, wrote:
> On Friday, September 28, 2018 at 11:03:17 AM UTC-7, Chris Green wrote:
> > I have a list created by:-
> >
> > fld = shlex.split(ln)
> >
> > It may contain 3, 4 or 5 entries according to data read into ln.
> > What's the neatest way of setting the fourth and fifth entries to an
> > empty string if they don't (yet) exist? Using 'if len(fld) < 4:' feels
> > clumsy somehow.
>
> How about this?
>
> from itertools import chain, repeat
> temp = shlex.split(ln)
> fld = list(chain(temp, repeat("", 5-len(temp
> --
> https://mail.python.org/mailman/listinfo/python-list
>
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Re: What's an elegant way to test for list index existing?
fld = [ ]
data = shlex.split(ln)
for item in data:
fld.append(item)
fld = fld + [0] * (5 - len(data))
On Sat, 29 Sep 2018 at 11:03, Glen D souza wrote:
> i have a approach, it may not be best
>
> fld = [ ]
> for data in shlex.split(ln):
>fld.append(data)
>
>
>
> On Sat, 29 Sep 2018 at 07:52, wrote:
>
>> On Friday, September 28, 2018 at 11:03:17 AM UTC-7, Chris Green wrote:
>> > I have a list created by:-
>> >
>> > fld = shlex.split(ln)
>> >
>> > It may contain 3, 4 or 5 entries according to data read into ln.
>> > What's the neatest way of setting the fourth and fifth entries to an
>> > empty string if they don't (yet) exist? Using 'if len(fld) < 4:' feels
>> > clumsy somehow.
>>
>> How about this?
>>
>> from itertools import chain, repeat
>> temp = shlex.split(ln)
>> fld = list(chain(temp, repeat("", 5-len(temp
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>>
>
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[issue27448] Race condition in subprocess.Popen which causes a huge memory leak
Glen Walker <g...@walker.gen.nz> added the comment: Correct me if I'm wrong, the change released in Python 2.7.15 doesn't actually fix this race condition. The race is: * T1: gc_was_enabled = gc.isenabled() # True * T1: gc.disable() * T2: gc_was_enabled = gc.isenabled() # False * T1: gc.enable() * T2: gc.disable() To fix the race condition _disabling_gc_lock must also be held for gc.enable() in both call locations so it cannot happen between gc.isenabled() and gc.disable(). TBH, I'm not really expecting this to be fixed, this is more a note for any future travelers who come across this issue. -- nosy: +gwalker ___ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue27448> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue33300] Bad usage example in id() DocString
New submission from Glen Neff <gn...@trioptimum.com>: The DocString for id() in 3.5.x & 3.6.x seems to have an incorrect usage example, specifically ``id(obj, /)``. This is present in 3.5.x & 3.6.x. It does not appear to be present in 2.7.x or 3.4.x.: Python 3.6.4 (v3.6.4:d48eceb, Dec 19 2017, 06:54:40) [MSC v.1900 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> help(id) Help on built-in function id in module builtins: id(obj, /) Return the identity of an object. This is guaranteed to be unique among simultaneously existing objects. (CPython uses the object's memory address.) >>> -- assignee: docs@python components: Documentation messages: 315410 nosy: docs@python, gneff priority: normal severity: normal status: open title: Bad usage example in id() DocString versions: Python 3.5, Python 3.6 ___ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue33300> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue24074] string, center, ljust, rjust, width paramter should accept None
New submission from Glen Fletcher: I've only list python 2.7, as I'm not sure that version 3 doesn't accept None, if so this should be changed there too. If these function are passed None, as the width they should return the string unchanged, just as they would for with a width set to 0. Reasoning, A common use of these would be in list comprehensions and such, i.e. (string.center(encode(i), w) for i, w in items, widths), given the that items and widths may be of differing length in theory i should be a empty string and width 0 it not specified however the best way of dealing with this would be to use itertools.izip_longest(items, widths, default=None) and None would be encode as No Value, however this would require writing (string.center(encode(i), 0 if w is None else w) for i, w in itertools.izip_longest(items, widths, default=None)), which is far harder to follow, when its quite reasonable to expect these string alignment functions to return an unpadded string if passed None as the width. -- components: Library (Lib) messages: 242215 nosy: glenflet priority: normal severity: normal status: open title: string, center, ljust, rjust, width paramter should accept None type: behavior versions: Python 2.7 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue24074 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
PyTexas 2014 Conference
Pythonistas, PyTexas 2014 http://pytexas.org/ is well on its way. This year it will be be located at the Texas AM University Memorial Student Center https://www.pytexas.org/2014/about/venue/ and will take place Friday October 3rd through Sunday October 5th. Friday will be a tutorial day. Saturday and Sunday will be talks. Registration for the conference is already open! http://www.eventbrite.com/e/pytexas-2014-registration-11825772203 This event is a great opportunity to meet with other Python folks, learn about what’s happening in the Python community, and spread the word about exciting projects using Python. We are currently looking for speakers and tutorials in all disciplines. Know about GIS, Scientific Computing, Math, Web, Standard Library, or have an itch to present your personal projects? We want you! We have more details on the PyTexas Site so stop on by and submit a talk today https://www.pytexas.org/2014/call-for-proposals/. Does your company use Python? Do they love Python as much we do? Sponsor! Sponsorship is a great way for your company to reach out to the Python community and let the world know how they use Python. Recruiting? No worries! We have sponsorships where you can set up a booth and speak with developers at the conference. Check out our sponsorship prospectus for more details https://www.pytexas.org/2014/sponsors/. During the conference we will provide breakfast, snacks, and lunch all three days. We have plenty of power so bring your laptop, hack away, and enjoy the conference. We look forward to seeing the community in a few months and stay tuned for any announcements on the PyTexas Site http://pytexas.org/ or PyTexas Twitter https://twitter.com/pytexas. Thanks for your time! PyTexas 2014 Organizers -- https://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations/
Re: Several Topics - Nov. 19, 2013
In comp.lang.fortran E.D.G. edgrs...@ix.netcom.com wrote: E.D.G. edgrs...@ix.netcom.com wrote in message news:ro-dnch2dptbrhnpnz2dnuvz_rsdn...@earthlink.com... Posted by E.D.G. on November 19, 2013 1. PERL PDL CALCULATION SPEED VERSUS PYTHON AND FORTRAN (snip) This program translation project has become one of the most surprisingly successful programming projects I have worked on to date. A considerable amount of valuable information has been sent to me by E-mail in addition to all of the information posted to the Newsgroups. The original posts actually discussed calculation speed matters involving Perl and Python. And responses indicated that there were ways to develop routines that could dramatically accelerate Python calculations. But it did not sound like there were any for Perl. In general, language processors can be divided into two categories called compilers and interpreters. Compilers generate instructions for the target processors. Interpreters generate (usually) an intermediate representation which is then interpreted by a program to perform the desired operations. That latter tends to be much slower, but more portable. There are a few langauges that allow dynamic generation of code, which often makes compilation impossible, and those languages tend to be called 'interpreted langauges'. Some years ago when working with perl programs that ran too slow, we found a perl to C translator. Surprisingly, the result ran just as slow! It turns out that the perl to C translator generates a C program containing the intermediate code and the interpreter, and so runs just the same speed. More recently, there are JIT systems which generate the intermediate code, but then at the appropriate time (Just In Time) compile that to machine code and execute it. This is common for Java, and more recently for languages like Matlab. -- glen -- https://mail.python.org/mailman/listinfo/python-list
Re: Several Topics - Nov. 19, 2013
In comp.lang.fortran Rainer Weikusat rweiku...@mobileactivedefense.com wrote:
glen herrmannsfeldt g...@ugcs.caltech.edu writes:
In comp.lang.fortran E.D.G. edgrs...@ix.netcom.com wrote:
E.D.G. edgrs...@ix.netcom.com wrote in message
news:ro-dnch2dptbrhnpnz2dnuvz_rsdn...@earthlink.com...
Posted by E.D.G. on November 19, 2013
1. PERL PDL CALCULATION SPEED VERSUS PYTHON AND FORTRAN
(snip)
This program translation project has become one of the most
surprisingly successful programming projects I have worked on to date. A
considerable amount of valuable information has been sent to me by E-mail
in
addition to all of the information posted to the Newsgroups.
(snip, I wrote)
In general, language processors can be divided into two categories
called compilers and interpreters. Compilers generate instructions for
the target processors. Interpreters generate (usually) an intermediate
representation which is then interpreted by a program to perform the
desired operations. That latter tends to be much slower, but more
portable.
There are a few langauges that allow dynamic generation of code, which
often makes compilation impossible, and those languages tend to be
called 'interpreted langauges'.
These two paragraphs use the same terms in conflicting ways and the
assertions in the second paragraph are wrong: Lisp is presumably the
oldest language which allows 'dynamic code creation' and implementations
exist which not only have a compiler but actually don't have an
interpreter, cf
http://www.sbcl.org/manual/index.html#Compiler_002donly-Implementation
The main difference between a compiler and an interpreter is that the
compiler performs lexical and semantical analysis of 'the source code'
once and then transforms it into some kind of different 'directly
executable representation' while an interpreter would analyze some part
of the source code, execute it, analyze the next, execute that, and so
forth, possibly performing lexical and semantical analysis steps many
times for the same bit of 'source code'.
OK, but many intepreters at least do a syntax check on the whole file,
and many also convert the statements to a more convenient internal
representation.
For an example of something that can't be compiled, consider TeX which
allows the category code of characters to be changed dynamically.
I once wrote self-modifying code for Mathematica, where the running code
(on what Mathematica calls the back end) asked the front end (which does
editing of input data) to change the code.
Some compilers produce 'machine code' which can be executed directly by
'a CPU', others generate 'machine code' for some kind of virtual machine
which is itself implemented as a program. The distinction isn't really
clear-cut because some CPUs are designed to run 'machine code'
originally targetted at a virtual machine, eg, what used to be ARM
Jazelle for executing JVM byte code directly on an ARM CPU, some virtual
machines are supposed to execute 'machine code' which used to run
'directly on a CPU' in former times, eg, used for backwards
compatibility on Bull Novascale computers.
Yes. There are also systems that do simple processing on each statement,
with no interstatement memory. Converting numerical constants to
internal form, encoding keywords to a single byte, and such.
It is interesting to see the program listing look different than the way
it was entered, such as constants coming out as 1e6 when you entered
it as 100. The HP2000 BASIC system is the one I still remember.
The popular microcomputer BASIC systems, mostly from Microsoft, allowed
things like:
IF I=1 THEN FOR J=1 TO 10
PRINT J
IF I=1 THEN NEXT J
If you left out the IF on the last line, it would fail when it reached
the NEXT J statement if the FOR hadn't been executed. Compare to C:
if(i==1) for(j=1;j=10;j++) {
printf(%d\n,j);
}
A compiler would match up the FOR and NEXT at compile time. Many
interpreters do it at run time, depending on the current state.
I also used to use a BASIC system that allowed you to stop a program
(or the program stopped itself), change statements (fix bugs) and
continue on from where it stopped. Not all can do that, but pretty
much compilers never do.
Prior to execution, Perl source code is compiled to 'machine code' for a
(stack-based) virtual machine. Both the compiler and the VM are provided
by the perl program. There were some attempts to create a standalone
Perl compiler in the past but these never gained much traction.
And, importantly, the code runs fairly slow. Some years ago, I was
working with simple PERL programs that could process data at 1 megabyte
per minute. Rewriting in C, I got one megabyte per second. It is not too
unusual to run 10 times slower, but 60 was rediculous.
-- glen
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struct calcsize discrepency?
In IPython:
import struct
struct.calcsize('4s')
4
struct.calcsize('Q')
8
struct.calcsize('4sQ')
16
This doesn't make sense to me. Can anyone explain?
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Re: struct calcsize discrepency?
On Dec 4, 9:38 am, Duncan Booth duncan.bo...@invalid.invalid wrote:
Glen Rice glen.rice.n...@gmail.com wrote:
In IPython:
import struct
struct.calcsize('4s')
4
struct.calcsize('Q')
8
struct.calcsize('4sQ')
16
This doesn't make sense to me. Can anyone explain?
When you mix different types in a struct there can be padding inserted
between the items. In this case the 8 byte unsigned long long must always
start on an 8 byte boundary so 4 padding bytes are inserted.
Seehttp://docs.python.org/library/struct.html?highlight=struct#byte-order-
size-and-alignment in particular the first sentence:
By default, C types are represented in the machine s native format and
byte order, and properly aligned by skipping pad bytes if necessary
(according to the rules used by the C compiler).
--
Duncan Boothhttp://kupuguy.blogspot.com
Chris / Duncan, Thanks. I missed that in the docs.
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Re: Python/Fortran interoperability
In comp.lang.fortran n...@cam.ac.uk wrote: (snip) Precisely. And the kludge does NOT work under all circumstances, which is why I said that it doesn't work very well. Consider, for example: SUBROUTINE Fred (X) BIND(C) CHARACTER*(*) :: X END SUBROUTINE Fred CHARACTER(LEN=100) :: string CALL Fred(string(40:60)) CALL Fred(string(5:50)) This is not currently allowed and raises all sorts of 'interesting' implementation and portability questions. For example, I defy anyone to write Fred portably in C :-) You mean, how does FRED know the length? It seems to me the usual question for Fortran assumed size arrays. Assuming that FRED can tell from the passed string, it seems fine to me. If not, it is a problem. Null terminated strings are a C convention, supported by the library and compiler (string constants). Others are legal C, though you have to be careful which library routines you use. It gets really hairy if you have functions that have assumed length results, but those are obsolescent. Even when Fred has an explicit length, there are some problematic cases, which could catch out programmers in one language that don't know the other fairly well. But those are much less of a problem than the common need for assumed length CHARACTER arguments. Maybe Fortran programmers who started in Fortran 66 will not have so much problem with this. The usual way would be to pass the length, as with assumed size arrays. I believe terminating strings with unusual (likely not null) characters was also done. -- glen -- http://mail.python.org/mailman/listinfo/python-list
Re: Numeric literal syntax
On Tue, 09 Sep 2008 08:32:29 +1000, Tom Harris wrote: I agree. So did Forth's early designers. That is why Forth's number parser considers a word that starts with a number and has embedded punctuation to be a 32 bit integer, and simply ignores the punctuation. I haven't used Forth in years, but it seems a neat solution to the problem of decoding a long string of numbers: let the user put in whatever they want, the parser ignores it. I usually used a comma (with no surrounding whitespace of course), but it was your choice. You could also do this in whatever base you were working in, so you could punctuate a 32 bit hex number to correspond to the bit fields inside it. Of course not applicable to Python. That sounds like a great idea, except I'd specify non-period (.) punctuation, so it would go for floating points as well. Is there a language design guru who can say why inputs like 123,456.00 couldn't be handles as above? the only problem I can see is an abiguity in argument lists (e.g. mult(2,4) ) which could be handled by the inclusion of whitespace. -- http://mail.python.org/mailman/listinfo/python-list
Re: What can we do about all the spam that the list is getting?
On Thu, 17 Apr 2008 13:30:18 -0500, Grant Edwards wrote: When using Google Groups can one kill all posts made via Google Groups? Presuming he has no burning need to see his own posts (something that can't be said for everybody in the history of Usenet), it might still be a viable approach. The problem is, if we had followed that advice, none of us would have seen his post. -- http://mail.python.org/mailman/listinfo/python-list
Re: lowercase class names, eg., qtgui ? (PyQt4)
On Thu, 26 Apr 2007 09:09:44 +0200, Tina I wrote: Hi Tina, Thanks for the reply. Of course, by now I've run pyuic4 again on my .ui file and things are back to normal. Believe it or not, my example was a copy/paste directly from my .py file. Some strange anomoly, I guess. Everything's ok now. Maybe vim was just displaying the text wrong for a minute. Had me going though. Thanks again. Glen Are you sure? That's strange. I have never seen that. Here is a snippet of one of my typical .py files generated by 'pyuic4': self.gridlayout = QtGui.QGridLayout(self.centralwidget) self.gridlayout.setMargin(9) self.gridlayout.setSpacing(6) self.gridlayout.setObjectName(gridlayout) self.hboxlayout = QtGui.QHBoxLayout() self.hboxlayout.setMargin(0) self.hboxlayout.setSpacing(6) self.hboxlayout.setObjectName(hboxlayout) self.hboxlayout1 = QtGui.QHBoxLayout() self.hboxlayout1.setMargin(0) self.hboxlayout1.setSpacing(6) self.hboxlayout1.setObjectName(hboxlayout1) Upper case all the way... Tina -- http://mail.python.org/mailman/listinfo/python-list
lowercase class names, eg., qtgui ? (PyQt4)
Hello, In the file generated by pyuic4 from Designer's .ui file I noticed the use of lower case class names (I'm assuming these are the names of classes, not modules). For example: It imports thusly: from PyQt4 import QtGui then uses things like: self.gridlayout = qtgui.qgridlayout(dldialog) What exactly is going on here? Are these instances that are defined somewhere else (their not in the local scope.)? Can I do the same in my code when I import something? Thanks, Glen Glen -- http://mail.python.org/mailman/listinfo/python-list
Re: Beginner: Formatting text output (PyQt4) Solved
Sorry I've been away a while, figuring stuff out. It absolutely wasn't a monospaced font that I was using. I'm still getting used to Qt Designer and didn't see the expandable item under 'font' where I could easily select another font. I felt pretty stupid when I saw it. My program output the contents of my data file perfectly once I selected a fixed pitch font. Thanks a lot for the replies. I didn't know how long to wait, since I'm new around here, and I kind of gave up. I got some good info from you guys anyway. Thanks. You'll probably be hearing from me pretty regularly, since I'm in the process of learning Python and PyQt simultaneously. Glen -- http://mail.python.org/mailman/listinfo/python-list
Re: Beginner: Simple Output to a Dialog PyQt4
On Sat, 21 Apr 2007 03:15:00 +0200, David Boddie wrote: On Tuesday 17 April 2007 07:42, Glen wrote: # Just to avoid any misunderstanding: the form is actually stored as XML. # You can create C++ code with uic or Python code with pyuic4. Right. I do remember noticing that when I opened one of the .ui files. Thanks for the instructions. I'm tackling signals and slots next. I'll be reading your post a few times, I'm sure. For the time being, just to get myself off the ground and see some output, I imported my functions from cnt.py into my main with 'from cnt import cnt'. Then I passed my QTextEdit object into my python code and output the contents of my file with: f = file(filename, 'r') for line in f: QTxtObj.insertPlainText(line) Maybe you could point out some problems with doing it this way, but I'm at the point now where I have to learn how to handle signals and slots. I'm setting up an input dialog with several options, such as download a URL, choose an existing file. Your information will come in handy. Glen [quoted text muted] OK. Ideally, your window will contain a button (or some other control) that the user can click to execute the functions. [quoted text muted] If, for example, you included a push button (QPushButton) in the form you created with Qt Designer, and called it executeButton, you could connect its clicked() signal to a function in cnt by including the following line after setting up the user interface: window.connect(ui.executeButton, SIGNAL(clicked()), cnt.myFunction) This assumes that your function is called myFunction(), of course. However, you wouldn't be able to get the output from this function back to the dialog just by using a signal-slot connection like this. One way to solve this would be to wrap the function using another function or instance that is able to modify the contents of the dialog. Another cleaner approach would be to subclass the user interface class (Ui_Dialog) and implement a custom slot that can both call the function and modify the dialog. For example: class Dialog(QDialog, Ui_Dialog) def __init__(self, parent = None): QDialog.__init__(self, parent) self.setupUi(self) self.connect(self.executeButton, SIGNAL(clicked()), self.callFunction) def callFunction(self): data = cnt.myFunction() # Do something with the data. Hope this gets you started, David -- http://mail.python.org/mailman/listinfo/python-list
Beginner: Formatting text output (PyQt4)
Hello again, I don't blame anyone for not answering my last post, since I obviously hadn't spent much time researching, but I've come a little ways and have another question. How can I better format text output to a QTextEdit object? I'm inserting 5 columns into each row. When I write the info to a file, it looks like the following: 42: 115 26: 114 35: 112 19: 108 16: 107 45: 107 40: 106 5: 105 41: 104 2: 103 9: 102 48: 102 15: 101 22: 101 27: 101 39: 101 43: 101 10: 100 6: 99 34: 99 32: 98 49: 98 20: 97 30: 97 8: 96 17: 96 38: 96 12: 95 14: 95 37: 95 4: 94 13: 94 44: 94 36: 93 3: 92 24: 92 28: 92 31: 91 29: 89 7: 88 1: 87 18: 85 46: 85 33: 84 11: 83 23: 83 47: 82 25: 80 21: 79 50: 56 52: 39 51: 38 53: 36 54: 25 55: 18 When I write the contents of the file to my TextEdit object it comes out uneven, something like this: 42: 11526: 11435: 11219: 10816: 107 45: 10740: 1065: 10541: 104 2: 103 9: 10248: 10215: 10122: 10127: 101 39: 10143: 10110: 1006: 9934: 99 32: 9849: 9820: 9730: 978: 96 17: 9638: 9612: 9514: 9537: 95 4: 9413: 9444: 9436: 933: 92 24: 9228: 9231: 9129: 897: 88 1: 8718: 8546: 8533: 8411: 83 23: 8347: 8225: 8021: 7950: 56 52: 3951: 3853: 3654: 2555: 18 What seems to be happening is that the font that pyqt is using is not fixed width, so I did this: qTxtFormat = QTextCharFormat() qTxtFormat.setFontFixedPitch(True) ui.textEdit.setCurrentCharFormat(qTxtFormat) Also, I tried using the pyqt formatting such as the following: qStr = QtCore.QString( QtCore.QString( str(tL2[i][0]) ).rightJustified(2) + ':' + QtCore.QString( str(tL2[i][1]) ).rightJustified(4) ) This still gives me uneven columns. Any suggestions? Thanks, Glen -- http://mail.python.org/mailman/listinfo/python-list
Re: Beginner: Formatting text output (PyQt4)
On Wed, 18 Apr 2007 22:50:14 +, Glen wrote: Ok, obviously, my post didn't come out the way I wanted it to. In the first example from my text file below, the dictionary pairs, constructed from sorted tuples were in straight columns. When I write them to my QTextEdit, however, the columns are no longer straight. Some of the padding inserted by my call to rightJustified() are not equal to the actual size of the text, so some rows are longer than others in the text browser. I know I've encountered this before, perhaps with Java, but I can't remember the solution. How do I get the formatting of my output to the gui to reflect the output I would get to a file using the builtin write() function? Any help is appreciated. Sorry about the confusion. Thanks, G Hello again, I don't blame anyone for not answering my last post, since I obviously hadn't spent much time researching, but I've come a little ways and have another question. How can I better format text output to a QTextEdit object? I'm inserting 5 columns into each row. When I write the info to a file, it looks like the following: 42: 115 26: 114 35: 112 19: 108 16: 107 45: 107 40: 106 5: 105 41: 104 2: 103 9: 102 48: 102 15: 101 22: 101 27: 101 39: 101 43: 101 10: 100 6: 99 34: 99 32: 98 49: 98 20: 97 30: 97 8: 96 17: 96 38: 96 12: 95 14: 95 37: 95 4: 94 13: 94 44: 94 36: 93 3: 92 24: 92 28: 92 31: 91 29: 89 7: 88 1: 87 18: 85 46: 85 33: 84 11: 83 23: 83 47: 82 25: 80 21: 79 50: 56 52: 39 51: 38 53: 36 54: 25 55: 18 When I write the contents of the file to my TextEdit object it comes out uneven, something like this: 42: 11526: 11435: 11219: 10816: 107 45: 10740: 106 5: 10541: 104 2: 103 9: 10248: 10215: 10122: 101 27: 101 39: 10143: 10110: 1006: 9934: 99 32: 9849: 98 20: 9730: 978: 96 17: 9638: 9612: 9514: 95 37: 95 4: 9413: 9444: 9436: 933: 92 24: 92 28: 9231: 9129: 897: 88 1: 8718: 8546: 8533: 8411: 83 23: 8347: 8225: 8021: 7950: 56 52: 3951: 38 53: 3654: 2555: 18 What seems to be happening is that the font that pyqt is using is not fixed width, so I did this: qTxtFormat = QTextCharFormat() qTxtFormat.setFontFixedPitch(True) ui.textEdit.setCurrentCharFormat(qTxtFormat) Also, I tried using the pyqt formatting such as the following: qStr = QtCore.QString( QtCore.QString( str(tL2[i][0]) ).rightJustified(2) + ':' + QtCore.QString( str(tL2[i][1]) ).rightJustified(4) ) This still gives me uneven columns. Any suggestions? Thanks, Glen -- http://mail.python.org/mailman/listinfo/python-list
Beginner: Simple Output to a Dialog PyQt4
Hello, I've written a script in python and put together a simple QFrame with a QTextBrowser with Designer. I've translated the C++ into python using puic4. The .py file is called outputWin.py. My Script and its functions are in cnt.py. Finally, my main is in pball.py which follows here: import sys from PyQt4 import Qt, QtCore from outputWin import * from cnt import * if __name__ == __main__: app = Qt.QApplication(sys.argv) window = Qt.QDialog() ui = Ui_Dialog() ui.setupUi(window) window.show() app.exec_() I want to call my functions in cnt and have an output to my QDialog. Can somebody give me a clue as to how to proceed? I can't find good an easy tutorial for PyQt4 and I've never used Qt before. -- http://mail.python.org/mailman/listinfo/python-list
Re: Access to static members from inside a method decorator?
Peter Otten wrote: [EMAIL PROTECTED] wrote: You define one base type with a custom metaclass and inherit from that. Your example then becomes: import sys class ExposedType( type ): def __init__( cls, *args, **kw ): # Track marked exposed methods cls.s_exposedMethods = [] for superclass in cls.__mro__: for name, meth in superclass.__dict__.items(): if hasattr( meth, exposed ): cls.s_exposedMethods.append( name ) class Exposed: __metaclass__ = ExposedType def getExposedMethods(self): return self.s_exposedMethods def bar(self): print bar\n @staticmethod def expose( f ): f.exposed = True return f class Process( Exposed): @Exposed.expose def foo( self ): pass def bar( self ): print BAR class BotProcess( Process ): @Exposed.expose def addBots( self ): pass p = Process() p.bar() This prints BAR as expected. Peter Thanks Peter. Yeah I had thought of that earlier, but wasn't sure if this is a standard design pattern for what I'm trying to achieve. It seems ugly to me to use 2 classes when you are essentially describing a single type. Is the Splat/SplatType pairing really a common design pattern when trying to use metaclasses in this way? Also ... as for the 'inspect' based solution, yeah I can see that would work, but it seems very hacky to me and my gut reaction is to avoid that kind of thing ... Cheers, Glen -- 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: Access to static members from inside a method decorator?
Thanks for all the help guys ... in almost every way using a metaclass seems to be the right solution for what I'm trying to do here. I say almost because there is one thing that is still confusing me: what is the most elegant way to provide base-class implementations of methods that are expected to be overriden by some of the derived classes (or in the case of metaclasses, the classes that either declare __metaclass__ = Exposed or are derived from such classes). Here's what I've just knocked out: import sys class Exposed( type ): def __init__( cls, *args, **kw ): # Track marked exposed methods cls.s_exposedMethods = [] for superclass in cls.__mro__: for name, meth in superclass.__dict__.items(): if hasattr( meth, exposed ): cls.s_exposedMethods.append( name ) # Add getExposedMethods method cls.getExposedMethods = lambda self: self.s_exposedMethods cls.bar = lambda self: sys.stdout.write( bar\n ) @staticmethod def expose( f ): f.exposed = True return f class Process( object ): __metaclass__ = Exposed @Exposed.expose def foo( self ): pass def bar( self ): print BAR pass class BotProcess( Process ): @Exposed.expose def addBots( self ): pass p = Process() p.bar() # The problem here is that the implementation of 'bar' inside Exposed.__init__ overrides the implementation of bar() in Process, which makes sense I guess seeing as Exposed.__init__() is called after the class has been initialised. It's not a problem for getExposedMethods() seeing as it's not overriden by any derived classes. So what is the accepted way of doing this? Do I need two Exposed classes, one is the metaclass that handles all the static mapping stuff, and another provides base implementations of methods and is what is actually derived from? E.g.: class ExposedMeta( type ): ... class Exposed( object ): ... class Process( Exposed ): __metaclass__ = ExposedMeta ... class BotProcess( Process ): ... Hmmm ... that seems a bit ugly too. If I change the assignments in Exposed.__init__() I guess I can avoid the two-class thing: cls.getExposedMethods = getattr( cls, getExposedMethods, lambda self: self.s_exposedMethods ) cls.bar = getattr( cls, bar, lambda self: sys.stdout.write( bar\n ) ) That's better, but still ugly. Is there a better way? Thanks for all the help thus far guys, Glen Maric Michaud wrote: 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
Access to static members from inside a method decorator?
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). 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. So how can this be done? It doesn't seem like it's possible to pass a reference to the enclosing class into the decorator, which in turn means that static tracking of the list of exposed methods is impossible (at least, if I want to use decorators). Any ideas that will enable my initial design, or suggestions for an elegant, workable alternative would be much appreciated. Cheers, Glen -- http://mail.python.org/mailman/listinfo/python-list
Detect TKinter window being closed?
Is it possible to to detect a Tkinter top-level window being closed with the close icon/button (top right), for example to call a function before the window actually closes? Python 2.4 / Linux (2.6 kernel) if that makes any difference. Any info would be greatly appreciated. Thanks Glen -- http://mail.python.org/mailman/listinfo/python-list
Re: Detect TKinter window being closed?
Thanks Fredrik and Adonis that's just what I needed, plus a bit more to learn about. -- http://mail.python.org/mailman/listinfo/python-list
How to stop a linux process
When I used the following line to play a midi file in linux,
return_value = os.system('timidity test.mid')
I have encountered two problems.
1. The python script halts until timidity has finished.
2. If I had control of the script, I can't think how I would stop timidity.
Any advice on the 'area' of python I should be looking at would be greatly
appreciated.
Thanks.
--
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Re: How to stop a linux process
Simon Brunning wrote: The subprocess module might be worth a look. That looks about right for what I need (once I understand it!). Thanks very much. -- http://mail.python.org/mailman/listinfo/python-list
Re: Newb: Telnet 'cooked data','EOF' queries
Could someone explain what cooked data is. discussed in the telnet RFC, which is in RFC854 telnetlib docstring. Cooked data is data after these special sequences are removed. 'when' is an EOF received. the only EOF in telnet is when the other side closes the socket. Thanks, thats got me started. -- http://mail.python.org/mailman/listinfo/python-list
Newb: Telnet 'cooked data','EOF' queries.
While experimenting with telnetlib, Ive come across a couple of 'features' that confuse me a little (lot!). Could someone explain what cooked data is. Also when trying read_all() the program seems to lock up, which I assume is because it is waiting for an EOF, but 'when' is an EOF received. Glen -- http://mail.python.org/mailman/listinfo/python-list
Begniner Question
#!/usr/local/bin/python import sys print 1.\tDo Something print 2.\tDo Something print 3.\tDo Something print 4.\tDo Something print 5.\tDo Something print 6.\tExit choice=raw_input(Please Enter Choice: ) if int(choice)==1: print Here else: pass if int(choice)==2: else: pass if int(choice)==3: else: pass if int(choice)==4: else: pass if int(choice)==5: else: pass if int(choice)==6: sys.exit(0) else: pass File ./Code.py, line 20 else: ^ IndentationError: expeted an indented block What am I doing wrong? Thank-you -- http://mail.python.org/mailman/listinfo/python-list
