Re: Strange terminal behavior after quitting Tkinter application
Am 03.11.20 um 23:34 schrieb Dennis Lee Bieber: Out of curiosity, does Python on Linux honor the .pyw extension? On Windows, .pyw indicates a Python program that implements a GUI and will NOT make use of console (stdin/stdout/stderr). On Linux, there is no such distinction. On Windows it is only needed because, if you connect stdin/out, a terminal window pops up. >For a true GUI program that is notr acceptable, the user will be puzzled what this ugly useless window wants to do, and therefore a flag in the EXE file format indicates to Windows if it should pop up the console or not. On Linux, stdin/out is always connected. You must run your program from a terminal window to see it, otherwise it is silently connected to some channel in the background by the desktop environment. It can happen that the standard channels are closed, if you run a program in the terminal and then close the terminal (which sends SIGHUP to the program). In this case the program might later on throw I/O errors, when printing to stdout. Christian -- https://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
On 2020-11-03 20:11, David Burnette wrote: On Wednesday, April 18, 2007 at 12:33:24 AM UTC-7, Chris wrote: Hi, I'm puzzled by some strange behavior when my Python/Tkinter application quits (on linux): the terminal from which I started Python is messed up. If start up python, then import the code below, then start the program with Application(), then click the Quit button, my terminal never prints anything again (such as commands I type). import Tkinter import sys class Application(Tkinter.Tk): def __init__(self,**config): Tkinter.Tk.__init__(self,**config) Tkinter.Button(self,text="Quit",command=self.quit_application).pack() def quit_application(self): sys.exit() Can anyone tell me what I'm doing wrong? Thanks for your help. Chris I notice this same behavior with other tk applications like "tkdiff". So what is the correct cleanup for a proper exit from a plain Tk application? Updated to Python 3, it should be more like this: import tkinter import sys class Application(tkinter.Tk): def __init__(self,**config): tkinter.Tk.__init__(self, **config) tkinter.Button(self, text="Quit", command=self.quit_application).pack() def quit_application(self): self.destroy() Application().mainloop() -- https://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
On Wednesday, April 18, 2007 at 12:33:24 AM UTC-7, Chris wrote: > Hi, > I'm puzzled by some strange behavior when my Python/Tkinter > application quits (on linux): the terminal from which I started Python > is messed up. > If start up python, then import the code below, then start the program > with Application(), then click the Quit button, my terminal never > prints anything again (such as commands I type). > > import Tkinter > import sys > class Application(Tkinter.Tk): > def __init__(self,**config): > Tkinter.Tk.__init__(self,**config) > > Tkinter.Button(self,text="Quit",command=self.quit_application).pack() > def quit_application(self): > sys.exit() > > > Can anyone tell me what I'm doing wrong? > Thanks for your help. > Chris I notice this same behavior with other tk applications like "tkdiff". So what is the correct cleanup for a proper exit from a plain Tk application? -- https://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
On May 7, 10:02 pm, Hamilton, William [EMAIL PROTECTED] wrote: From: Chris I'll admit to being surprised at seeing a claim that atkinter application, started within an interactive session, without a mainloop, even runs... I could see it maybe happening from Idle, since Idle is running atkintermainloop, so the application bindings may have just become added widgets to the Idle loop (but of course, a second mainloop would conflict heavily). You can try by building a workingTkinterGUI interactively from the standard Python interpreter, and see that the GUI works (i.e. processes events) at the same time. If you build it as a class (such as the code in Chris's original post) it works; if you do it all directly, nothing happens until you run mainloop(). It works, but I'm not sure that it was intended to work that way. I think your problem is related to that difference. Do you have any idea where I should go to find out the differences between using mainloop() and not using it? So far I have found this quitting problem (which does not occur on all platforms), and the need to call update() or update_idletasks() after some operations, but no others. You'll probably be better off creating a new interpreter window as part of your program, if you really need access to the interpreter alongside your GUI. You may be able to extract IDLE's interpreter window and use it directly. I really do need access to the interpreter alongside the GUI in my real program*, since the GUI cannot really offer all the functionality of the command line (or is a long way from doing so...). I do offer simple access to the interpreter in my gui (via code.InteractiveConsole and a text widget, but I agree with the author of the comp.lang.python posting Has anybody made a Tkinter text widget into a terminal emulator? (http://groups.google.com/group/ comp.lang.python/browse_thread/thread/a3f223f563205156/ fc729e1de51ca2dc): it's a shame to force people to use a particular editor. I don't know if she found a solution; I haven't found anything reasonable yet. Thanks * Actually it's not my program, it's an open-source software package for modelling neural maps: topographica.org. The GUI code is being reorganized. -- http://mail.python.org/mailman/listinfo/python-list
RE: Strange terminal behavior after quitting Tkinter application
From: Chris I'll admit to being surprised at seeing a claim that a tkinter application, started within an interactive session, without a mainloop, even runs... I could see it maybe happening from Idle, since Idle is running a tkinter mainloop, so the application bindings may have just become added widgets to the Idle loop (but of course, a second mainloop would conflict heavily). You can try by building a working Tkinter GUI interactively from the standard Python interpreter, and see that the GUI works (i.e. processes events) at the same time. If you build it as a class (such as the code in Chris's original post) it works; if you do it all directly, nothing happens until you run mainloop(). It works, but I'm not sure that it was intended to work that way. I think your problem is related to that difference. You'll probably be better off creating a new interpreter window as part of your program, if you really need access to the interpreter alongside your GUI. You may be able to extract IDLE's interpreter window and use it directly. --- -Bill Hamilton -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
On May 5, 2:21 pm, Dennis Lee Bieber [EMAIL PROTECTED] wrote: On 4 May 2007 19:38:39 -0700, Chris [EMAIL PROTECTED] declaimed the following in comp.lang.python: Thanks, but I was just explaining why I don't want to call mainloop(). In my original example, I can type Application() at the interactive prompt and get a GUI (which seems to work apart from not quitting properly and leaving a messed-up terminal on some versions of linux) while still being able to use the interactive interpreter. I guess I'm confused by while still being able to use the interactive interpreter... Unless your Application() starts a separate thread to handle the GUI interaction, the interpreter itself will not interact until it exits and returns control to the interpreter. Maybe the Python interpreter is setup specially for Tkinter, I don't know - but one can definitely have a Tkinter GUI working and use the interpreter too (by not calling mainloop()). The Application example in my first post works (except for the messed-up terminal) and the interpreter is not blocked. Perhaps it becomes necessary to call update or update_idletasks() after some operations for the GUI to update itself - I'm not entirely sure (I haven't been able to find any documentation) - but apart from that there are no problems I know about. I need to find out what cleanup is performed after mainloop() exists, I guess. G If you are calling it, it exists... Whether it exits is another matter G Incidentally, I found the information in the thread http://thread.gmane.org/gmane.comp.python.scientific.user/4153 quite useful regarding mainloop() and being able to use python interactively from the prompt while still having a GUI. I'll admit to being surprised at seeing a claim that a tkinter application, started within an interactive session, without a mainloop, even runs... I could see it maybe happening from Idle, since Idle is running a tkinter mainloop, so the application bindings may have just become added widgets to the Idle loop (but of course, a second mainloop would conflict heavily). You can try by building a working Tkinter GUI interactively from the standard Python interpreter, and see that the GUI works (i.e. processes events) at the same time. That link reads as if the IronPython interpreter can be started with a wx/gtk mainloop already running as a thread -- so any application code might, as with my tkinter/Idle thoughts, be added to the already running loop. I don't know how ipython works, just that it allows a GUI and interpreter to work together for wxpython (whereas usually you can only use a GUI and the python interpreter when the GUI is Tkinter). Chris -- http://mail.python.org/mailman/listinfo/python-list
RE: Strange terminal behavior after quitting Tkinter application
-Original Message-
From: Chris
Subject: Re: Strange terminal behavior after quitting Tkinter
application
Clicking 'Quit' or on the window's 'x' causes the application to quit
without messing up the terminal. With root.mainloop() commented out,
though, no combination of root.quit(), root.destroy(), and sys.exit()
stops the terminal from getting messed up.
So, I should call mainloop() for my application...except that I want
to use the commandline, too, and calling mainloop() freezes the
commandline. I wonder if there is another way to use the commandline
and have a GUI? I couldn't find any clear information about that.
Can you run it in the background? IIRC, if you put an ampersand ('')
at the end of the command line, it will run as a background process and
leave your command line available for other tasks. (The marker may be
something other than , it's been a long, long time since I've used *nix
in a gui environment.)
---
-Bill Hamilton
--
http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
On May 4, 8:52 pm, Hamilton, William [EMAIL PROTECTED] wrote:
-Original Message-
From: Chris
Subject: Re: Strange terminal behavior after quittingTkinter
application
Clicking 'Quit' or on the window's 'x' causes the application to quit
without messing up the terminal. With root.mainloop() commented out,
though, no combination of root.quit(), root.destroy(), and sys.exit()
stops the terminal from getting messed up.
So, I should call mainloop() for my application...except that I want
to use the commandline, too, and calling mainloop() freezes the
commandline. I wonder if there is another way to use the commandline
and have a GUI? I couldn't find any clear information about that.
Can you run it in the background? IIRC, if you put an ampersand ('')
at the end of the command line, it will run as a background process and
leave your command line available for other tasks. (The marker may be
something other than , it's been a long, long time since I've used *nix
in a gui environment.)
Ah, sorry, I wasn't being precise. I meant the python commandline
python interpreter.
So from a terminal I type (for example):
python -i application.py
This launches the interpreter in my terminal. Then I can start the GUI
(by typing Application(), for example). If I use mainloop(), I can't
interact with the interpreter from the terminal until I quit the GUI.
Without mainloop(), I can continue to enter python commands.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
On May 5, 1:24 am, Dennis Lee Bieber [EMAIL PROTECTED] wrote: On 4 May 2007 08:02:13 -0700, Chris [EMAIL PROTECTED] declaimed the following in comp.lang.python: Ah, sorry, I wasn't being precise. I meant the python commandline python interpreter. So from aterminalI type (for example): python -i application.py This launches the interpreter in myterminal. Then I can start the GUI (by typing Application(), for example). If I use mainloop(), I can't interact with the interpreter from theterminaluntil I quit the GUI. Without mainloop(), I can continue to enter python commands. Which is to be expected... As the name implies, it is a loop. The Python interpreter doesn't produce an interactive prompt until it runs out of code to execute. Enter the following at an interactive prompt and see what happens: while True: pass mainloop() is similar, though filled out with event dispatching logic: while True: #get input event (keyboard, mouse clicks, mouse motion, etc.) #call handler for that type of event All common GUI toolkits work this way (The AmigaOS was pretty much the only exception, in that it did NOT natively rely upon binding callbacks to events and then starting a library loop; one had to code the dispatch loop by hand -- but this did mean that one could code a subloop within an event handler if needed to restrict the available events). Thanks, but I was just explaining why I don't want to call mainloop(). In my original example, I can type Application() at the interactive prompt and get a GUI (which seems to work apart from not quitting properly and leaving a messed-up terminal on some versions of linux) while still being able to use the interactive interpreter. I need to find out what cleanup is performed after mainloop() exists, I guess. Incidentally, I found the information in the thread http://thread.gmane.org/gmane.comp.python.scientific.user/4153 quite useful regarding mainloop() and being able to use python interactively from the prompt while still having a GUI. -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
(I apologize if some similar version of this message has already appeared; I've tried several time to post it, seemingly without success.) If that is satisfactory, well and good. However, there is a possibility that you may lose some settings that you would prefer to keep. The terminal settings have been trashed, and stty sane has restored a minimally workable set, but some settings may not be what you expect. I agree: I'll consider saving the terminal settings as you suggest. Just in case, I did a google search. I am not familiar withTKinter, but a couple of articles out there imply that rather than calling sys.exit you should be calling aTkInterroutine root.destroy. I am not sure if root is a variable for the main window (ie you call the destroy method on the main window) or if it has some specialTkintermeaning. Presumably this routine cleans things up before calling sys.exit or an equivalent. root is the name of a variable typically used by people to hold an instance of Tkinter.Tk, the main application window (from http://epydoc.sourceforge.net/stdlib/Tkinter.Tk-class.html: Toplevel widget of Tk which represents mostly the main window of an appliation. It has an associated Tcl interpreter.). Instead of subclassing Tkinter.Tk and instantiating that subclass for my application, I could create a Tk instance and withdraw() it, then use a Toplevel. In my example code above, I could call any 'root' methods on an instance of my Application class, presumably with the same effect. In any case, that might not be important - I think the problem comes from not calling mainloop(): code import Tkinter import sys root = Tkinter.Tk() Tkinter.Button(root,text=Quit,command=sys.exit).pack() root.mainloop() /code Clicking 'Quit' or on the window's 'x' causes the application to quit without messing up the terminal. With root.mainloop() commented out, though, no combination of root.quit(), root.destroy(), and sys.exit() stops the terminal from getting messed up. So, I should call mainloop() for my application...except that I want to use the commandline, too, and calling mainloop() freezes the commandline. I wonder if there is another way to use the commandline and have a GUI? I couldn't find any clear information about that. Thanks again, Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
Chris wrote: ... Quitting by typing 'sys.exit()' in the interpreter also works fine. Only quitting via the GUI seems to cause the problem. As previously stated, I know nothing about Tkinter, but it definitely looks like there is some cleanup being skipped on a GUI exit that is in fact being run on exit via ^D and sys.exit from the terminal. If I remember correctly, the low level details of how this sort of thing is usually handled on unix like systems is for the application to - Do an ioctl TCGETA system call to get the current settings, and save them somewhere. - Do an ioctl TCSETA system call to change the settings. - Arrange, via signal handlers, atexit, or other means for a cleanup routine to be called on exit. - The cleanup routine does an ioctl TCSETA call with the saved settings. (all this would typically involve C calls) I believe that in your case this last cleanup is being omitted on exit via the GUI. For the moment, including the line 'os.system(stty sane)' before sys.exit() is the solution I'll use. If that is satisfactory, well and good. However, there is a possibility that you may lose some settings that you would prefer to keep. The terminal settings have been trashed, and stty sane has restored a minimally workable set, but some settings may not be what you expect. If you are on a unix like system (eg Linux), and can wrap your Tkinter application in a shell script, you should be able to save/restore the settings outside of Tkinter and python, ie #! /bin/sh saved_settings=`stty -g` i# Note backquotes, save current settings python Tkinter-application.py # Or whatever stty $saved_settings i# Restore settings Doing the save within the Tkinter application, with (for example) os.system(stty -g saved_settings) and os.system(stty `cat saved_settings`) may not work as the setting may have been changed by Tkinter before you get a chance to save them - I just do not know. Just in case, I did a google search. I am not familiar with TKinter, but a couple of articles out there imply that rather than calling sys.exit you should be calling a TkInter routine root.destroy. I am not sure if root is a variable for the main window (ie you call the destroy method on the main window) or if it has some special Tkinter meaning. Presumably this routine cleans things up before calling sys.exit or an equivalent. Charles -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
Is there some Tkinter clean up that you have omitted ? Not that I know about - I was hoping someone would tell me I'd omitted something. Have you ensured that the clean up runs on both normal exit and abnormal exit (eg ^C) ? (^C doesn't make the application exit, it just raises a KeyboardInterrupt error.) Quitting with ^D from the interpreter (the usual way to quit Python) causes the application to quit normally without any subsequent terminal trouble. Quitting by typing 'sys.exit()' in the interpreter also works fine. Only quitting via the GUI seems to cause the problem. For the moment, including the line 'os.system(stty sane)' before sys.exit() is the solution I'll use. Thanks for everyone's help. -- http://mail.python.org/mailman/listinfo/python-list
Strange terminal behavior after quitting Tkinter application
Hi, I'm puzzled by some strange behavior when my Python/Tkinter application quits (on linux): the terminal from which I started Python is messed up. If start up python, then import the code below, then start the program with Application(), then click the Quit button, my terminal never prints anything again (such as commands I type). code import Tkinter import sys class Application(Tkinter.Tk): def __init__(self,**config): Tkinter.Tk.__init__(self,**config) Tkinter.Button(self,text=Quit,command=self.quit_application).pack() def quit_application(self): sys.exit() /code Can anyone tell me what I'm doing wrong? Thanks for your help. Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
(I'm not sure what happened to the formatting in my post: the Tkinter.Button line should be at the same level of indentation as the Tkinter.Tk.__init__ line.) -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
On Apr 18, 2007, at 2:33 AM, Chris wrote: I'm puzzled by some strange behavior when my Python/Tkinter application quits (on linux): the terminal from which I started Python is messed up. If start up python, then import the code below, then start the program with Application(), then click the Quit button, my terminal never prints anything again (such as commands I type). code import Tkinter import sys class Application(Tkinter.Tk): def __init__(self,**config): Tkinter.Tk.__init__(self,**config) Tkinter.Button(self,text=Quit,command=self.quit_application).pack() def quit_application(self): sys.exit() /code Can anyone tell me what I'm doing wrong? What happens if you type 'stty sane' (and of course, a carriage return) afterwards? -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
What happens if you type 'stty sane' (and of course, a carriage return) afterwards? The terminal returns to normal, thanks! But does anyone know why the Tkinter program is doing this to the terminal in the first place? I don't want to have to tell users of my program that they must recover their terminal's sanity each time after running my program. -- http://mail.python.org/mailman/listinfo/python-list
Re: Strange terminal behavior after quitting Tkinter application
Chris wrote: But does anyone know why the Tkinter program is doing this to the terminal in the first place? I don't want to have to tell users of my program that they must recover their terminal's sanity each time after running my program. I don't know about Tkinter, but my guess would be that it has to change the terminal settings to do what it does, and you are quitting without restoring the settings. Is there some Tkinter clean up that you have omitted ? Have you ensured that the clean up runs on both normal exit and abnormal exit (eg ^C) ? For example, the curses library (in C) requires an endwin() call before exit to restore settings. If this is omitted, a stty sane is needed to set the terminal to a semi-sensible default. On Unix and similar systems, signal handlers are normally installed to ensure (as far as possible) that the cleanup occurs if the process is killed. This also applies to vi and similar programs that take total control of the terminal. Charles -- http://mail.python.org/mailman/listinfo/python-list
