🌐 Mailman 3 June 1999 - Python-list - python.org

newbie question about tkFileDialog.py
by Dinesh Shanbhag (c) July 5, 1999

July 5, 1999

I am using the 'tkFileDialog.py' module to open a file. To allow the user to select a file I can use tkFileDialog.askopenfilename or tkFileDialog.asksaveasfilename. I also want the user to be able to select a Directory on the similar lines... Did not find anything like tk_getOpenFile in the Tcl/Tk man pages for selecting Directories... Am i missing something obvious ? thanks in advance for any help, dinesh.

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Python GUIs: Summary and Conclusion
by mikael＠pobox.com July 3, 1999

July 3, 1999

Hi, I think there is a sufficient number of replies to my original "Python GUIs: Abondining TkInter and welcoming wxPython" post that a conclusion can be made. Thanks to all who replied; the replies did exactly what I wanted - presented a lot of arguments for and against a switch from TkInter to wxPython. Arguments for keeping TkInter: 1. It is the most widely portable GUI. 2. It is the most flexible GUI (at least compared to wxWindows). 3. It is the most widely used GUI, documented in several books. Arguments for promoting wxWindows: 1. It is the fastest GUI (compared to TkInter). Two other GUIs, The FastLight Toolkit and PyKDE/Qt, were mentioned, but they both fall outside the domain of this discussion because they're not portable enough (one of the primary tasks of a standard GUI must be to be available on any, or most, Python hosts). One other "GUI", JPI, was mentioned and dismissed because it requires Java (so the GUI developer must know two scripting languages to make GUIs in one of them). However, this may be useful to some since it gives JPython and CPython developers one GUI tool. Really useful clues to why TkInter does not perform as well as it should: (Michael P. Reilley) But.. the argument over (these two) GUIs is not exactly a valid one. Tkinter was written using the Tcl interface not the Tk/C API. If Tkinter was rewritten to use the C API, it probably wouldn't be slower than wxPython. Ideas to make wxPython/wxWindows more portable, which the wxPython community may consider to implement: (Alexander V. Voinov) Well, let's write a sort of wxTk, and have that everywhere, where no wxNative runs yet. URLs for the various GUIs (excluding TkInter): wxPython - http://alldunn.com/wxPython/ PyKDE/Qt - http://www.river-bank.demon.co.uk/software/ JPI - http://www.ndim.edrc.cmu.edu/dougc/jpi/Home.html Conclusion (my conclusion, at least...): TkInter should continue to be the de-facto standard Python GUI. Primarily because of its matureness, some say better design philosophy, its portability, and its popularity. wxPython continues to be a good alternative, as does others, which may be better in specific situations and to some developers. The TkInter module(s) should be rewritten to employ the native Tk API, instead of Tcl, which would probably eliminate all sluggishness in client applications. More widgets should be added to Tk(Inter). Anyone disagree? Any volunteers to start work on making a native Tk C API version of TkInter, 100 percent backwards compatible of course? -- Mikael

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Mailbox, tell and read
by Paul Prescod July 3, 1999

July 3, 1999

The mailbox message objects simulate a file interface by seeking through a mailbox. A read() returns the entire message. It does this by seeking to the start, reading to the message end, and returning the data. The problem is that message offsets are derived by file.tell() which I presume is in terms of bytes. But then it does a read() based on the offsets and read() is in terms of characters. These don't match up on Windows because of CR/LF pairs. I think that the right fix is to never use tell() and instead keep track of the location by counting characters. Does that make sense? -- Paul Prescod - ISOGEN Consulting Engineer speaking for only himself http://itrc.uwaterloo.ca/~papresco "I don't want you to describe to me -- not ever -- what you were doing to that poor boy to make him sound like that; but if you ever do it again, please cover his mouth with your hand," Grandmother said. -- John Irving, "A Prayer for Owen Meany"

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Problem embedding C++ code
by mukundd＠my-deja.com July 3, 1999

July 3, 1999

Hi, I am trying to write a wrapper around a library written in C++ and I am running into lots of problems. I am running Python 1.5.2 on SunOS 5.5.1 (compiled with SUN's cc and linked with Sun's CC) The wrapper is written in a file called link-wrap.c and currently it contains only one very simple function. CC -c -KPIC link-wrap.c -I/home/mdeshpan/SW/include/python1.5 "link-wrap.c", line 13: Warning: String literal converted to char* in formal argument 1 in call to Py_BuildValue(char*, ...). 1 Warning(s) detected. CC -G link-wrap.o -lapic -lpthread -o link.so libapic.so is the library which I am trying to write the wrapper for, it was compiled using Sun's CC compiler when I try to import link module in python I get the following error.. daffy:~/Swig$python Python 1.5.2 (#3, Jun 29 1999, 11:17:23) [C] on sunos5 Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam >>> import link Traceback (innermost last): File "<stdin>", line 1, in ? ImportError: ld.so.1: python: fatal: relocation error: file ./libapic.so: symbol _ex_rethrow_q: referenced symbol not found any help would be greatly appreciated.. Thanks in advance Mukund Sent via Deja.com http://www.deja.com/ Share what you know. Learn what you don't.

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Why must path be in args in os.execv?
by Holger Jannsen July 2, 1999

July 2, 1999

High, there's again something I don't understand. Hope you do.;-) I'd like to start a windows-executable with some arguments. Ok. 'os.execv' or anything like that is the thing. But if I don't repeat the path with the arguments, the execution fails. Better: Something happens, but not the correct execution. For testing I constructed an easy batch named test.bat with only one command: echo %0 %1 %2 %3 %4 %5 >result.log Python 1.5.2 (#0, Apr 13 1999, 10:51:12) [MSC 32 bit (Intel)] on win32 Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam >>> import os >>> os.chdir("c:\\mypython") >>> os.execv("test.bat",["test.bat","1","2","3","4"]) When I start with: >>> os.execv("test.bat",["1","2","3","4"]) only the interpreter ends. No Log-File has been written... I really spent a long time since I found out. Perhaps the documentation have to be changed? >>> execv (path, args) Execute the executable path with argument list args, replacing the current process (i.e., the Python interpreter). The argument list may be a tuple or list of strings. Availability: Unix, Windows. >>> Ciao, Holger

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win32com.client -- beginner question
by Axel Schmitz-Tewes July 2, 1999

July 2, 1999

Hello, I ' ll try to use the comclient ability of python. In the Doku I have found the example: o = win32com.client.Dispatch("Excel.Application") o.Visible = 1 o.Workbooks.Add() # for office 97 95 a bit different! o.Cells(1,1).Value = "Hello" Because I have installed Excel95 I have given it a try and that's the result: Python 1.5.2 (#0, Apr 13 1999, 10:51:12) [MSC 32 bit (Intel)] on win32 Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam >>> import win32com.client >>> o= win32com.client.Dispatch("Excel.Application") >>> o.Workbooks.Add() Traceback (innermost last): File "<stdin>", line 1, in ? File "E:\Programme\Python\win32com\client\dynamic.py", line 400, in __getattr_ _ raise AttributeError, "%s.%s" % (self._username_, attr) AttributeError: Excel.Application.Workbooks But Workbooks.Add is a available method as I can test with VBScript. Is my installation corrupt or do I do some silly mistake or perhaps some more serious? Thanks for any answer. Regards, Axel

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total idiot question: +=, .=, etc...
by Preston Landers July 2, 1999

July 2, 1999

Hi there, another question in this popular series of foolish questions... Can someone *please* give me a good reason why Python doesn't yet have +=, -=, and .= and other such operators? I know it's just syntactic sugar, but damn, it is such sweet sugar! Also, if this is in 1.5.2+, please forgive me, as I'm not up to speed on the new versions yet. And I have searched the FAQ for this question but have not found it. many thanks, ---Preston

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theads & global namespaces
by Taylor Anderson July 1, 1999

July 1, 1999

Greetings all, I am trying to share globals between threads. Is is possible for me to share globals between threads that call functions from different modules? Thus far I have had little success. I ask this question because I would prefer not to put all my code in one module. For example, I have 2 .py files: a.py and b.py. b.py contains the function ('foo()') to be executed under the new thread, as well as the global variable 'x'. a.py contains the call to start_new_thread(foo,()). a.py also tries to use the global variable x. ========================================= b.py x = 0 def foo(): global x x = x + 1 ========================================= a.py from b.py import * if __name__ == '__main__': start_new_thread(foo, ()) while 1: if x != 0: print x ========================================= So far, my code in a.py does not detect any change in x. Any suggestions for a workaround? Many thanks, Taylor

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Help: Can you explain this error? (contains code snip)
by H. P. Friedrichs July 1, 1999

July 1, 1999

Hello: This is week 2 for me in python...What fun! I have stumbled across an interesting problem. When the code below is run under Win95 (python 1.5.2),it works without problems. If the same code is run under Linux (python 1.4) I get the error: Traceback (innermost last): File "socksrv3.py", line 100, in ? han=int(handle) #extract integer representation of handle TypeError: int() argument can't be converted to int The code section below is part of a larger program that receives ascii "link messages" through a TCPIP socket. The format for the message is as follows: an ascii "handle" followed by a tilde, followed by an ascii "verb", followed by a tilde, and concludes with an ascii "value" An example looks like this: "123~opensym~0" Anyhow, the code below uses splitfields to break the message into it's constituent parts. Later, at the line signified by the marker "====>" the program blows up when I attempt to convert the string "handle" into it's integer equivalent. What gives? Is the 1.4 version of python buggy, or am I overlooking something? Thanks for your help in advance. Pete #*** receive link msg **** cmd=conn.recv(1024) #try to get a message if not cmd: print"closing connection..." conn.close() #good housekeeping...close cnnctn break #*** extract components of link message *********** fieldlist=splitfields(cmd,"~") #break message to constituents handle=fieldlist[0] #extract handle verb=fieldlist[1] #extract verb value=fieldlist[2] #extract value #****** if command requested write to existing symbol, do this: if verb == "writesym": ====> han=int(handle) #extract integer representation of handle masterdict[han]=float(value) response=handle+"~"+verb+"~"+value #build response string print "tx'd response:",response print "dict status: ",masterdict conn.send(response) #send response continue -- ----------------------------------------------- | The opinions expressed here are my own, | | and not necessarily those of my employer. | -----------------------------------------------

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How to obtain an instance's name at runtime?
by Dinu C. Gherman July 1, 1999

July 1, 1999

This is a nasty question, perhaps, so I appologize in advance if its stupidity level is far above the accepted average in this newsgroup... I would like to do the following: >>> class C: ... pass ... >>> >>> c = C() >>> C.__class__.__name__ # ok 'C' >>> c.__name__ # not ok Traceback (innermost last): File "<interactive input>", line 0, in ? AttributeError: __name__ >>> Question: How to obtain an instance's name at runtime? That is I'd like to see this happen (one was or the other): >>> c.__name__ 'c' I've checked the reference manual, but it's silent about this topic or I'm too blind... Fearing-there's-no-such-solution'ly, Dinu PS: Do not use my Deja email-address. Sent via Deja.com http://www.deja.com/ Share what you know. Learn what you don't.

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