🌐 Mailman 3 December 2014 - Python-list - python.org

[ANN] EasyGUI_Qt version 0.9
by André Roberge Jan. 14, 2015

Jan. 14, 2015

EasyGUI_Qt version 0.9 has been released. This is the first announcement about EasyGUI_Qt on this list. Like the original EasyGUI (which used Tkinter), EasyGUI_Qt seeks to provide simple GUI widgets that can be called in a procedural program. EasyGUI_Qt is NOT event-driven: all GUI interactions are invoked by simple function calls. The archetype is get_string(message) which pops a box whose purpose is exactly the same as Python's input(prompt), that is, present the user with a question/prompt, have the user enter an answer, and return the provided answer as a string. Thus easygui_qt.get_string() can be used as a drop-in replacement for input(). Similarly, instead of using a print() function to display a message, show_message() is used which pops a message window. EasyGUI_Qt requires PyQt4 and is really targeted for Python 3.3+ - although it can work (possibly with some unicode problems ...) using Python 2.7. More information can be found at http://easygui-qt.readthedocs.org/en/latest/index.html Feedback is most welcome, including reporting bugs to https://github.com/aroberge/easygui_qt/issues Happy 2015 everyone, André Roberge

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PyGILState API and Py_Main
by Adrien Bruneton Jan. 8, 2015

Jan. 8, 2015

Hello all, I am having a hard time understanding what is the proper use of PyGILState_Ensure/Release. My understanding is that one should always be matched with the other, and that this high level API auto-magically deals with the ThreadState creation. However the following piece of code (executed with a simple "print 'hello world' " script as argv) triggers the message: Fatal Python error: auto-releasing thread-state, but no thread-state for this thread Minimal code: void initPython(int initsigs) { if (Py_IsInitialized() == 0) { Py_InitializeEx(initsigs); // Put default SIGINT handler back after Py_Initialize/Py_InitializeEx. signal(SIGINT, SIG_DFL); } int threadInit = PyEval_ThreadsInitialized(); PyEval_InitThreads(); // safe to call this multiple time if(!threadInit) PyEval_SaveThread(); // release GIL } int main(int argc, char ** argv) { initPython(1); PyGILState_STATE _gstate_avoid_clash = PyGILState_Ensure(); int ret = Py_Main(argc, argv); PyGILState_Release(_gstate_avoid_clash); // this one triggers the Fatal error Py_Finalize(); return ret; } Removing the last PyGILState_Release works, but I have a bad feeling about it :-) Any help would be welcome! Thanks in advance. Adrien.

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Python console rejects an object reference, having made an object with that reference as its name in previous line
by Simon Evans Jan. 4, 2015

Jan. 4, 2015

Dear Python programmers, Having input the line of code in text: cd Soup to the Windows console, and having put the file 'EcologicalPyramid.html' into the Directory 'Soup', on the C drive, in accordance with instructions I input the following code to the Python console, as given on page 30 of 'Getting Started with Beautiful Soup': ---------------------------------------------------------------------------- Python 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)] on win 32 Type "help", "copyright", "credits" or "license" for more information. >>> from bs4 import BeautifulSoup >>> with open("ecologicalpyramid.html","r") as ecological_pyramid: ... soup = BeautifulSoup(ecological_pyramid,"lxml") ... producer_entries = soup.find("ul") ^ SyntaxError: invalid syntax >>> producer_entries = soup.find("ul") Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'soup' is not defined >>> ^ ---------------------------------------------------------------------------- so I cannot proceed with the next line withh would 've been : ---------------------------------------------------------------------------- print(producer_entries.li.div.string) ---------------------------------------------------------------------------- which would've given (according to the book) the output: --------------------------------------------------------------------------- plants Maybe that is getting a bit far ahead, but I can't quite see where I have gone wrong - 'soup' has been defined as an object made of file 'EcologicalPyramid.html I hope you can help me on this point. Yours Simon

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Enumerating loggers iin logging module
by jptechnical.co.uk Jan. 3, 2015

Jan. 3, 2015

Hello all, I've recently started using the logging module and wondered if there was a way to enumerate all the Logger objects available as a result of calls to "logging.getLogger(name)". Went through the docs and could not spot any way of doing this. Have I missed something? It would have been useful to list the Loggers created in an app as I'd made the mistake of writing: in module A: logging.getLogger("Name") in module B: logging.getLogger("name.sublogger") and wondered why messages sent to "name.sublogger" did not get passed to the parent handler in "Name". A list of of available loggers would have quickly shown the error of my ways. I'm using Python 2.7.8 Any help appreciated, Regards John

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Python Tk Tix GUI documentation & builder overview and tips
by baloand＠googlemail.com Jan. 3, 2015

Jan. 3, 2015

I have recently started development for a small video conversion project using a GUI. After some research I decided to use Tkinter/Tix (Tk/Tix). The reasons are mainly: 1. the GUI is rather simple, and 2. the end-user is not necessarily technically inclined so I want to keep a) required libraries as few as possible, and b) installation as painless as possible. 3. Tk/Tix is included with Python. Thus only a Python installation is needed. Nothing else. 4. Tk itsself misses some rudimentary widgets like meters, multi/colum lists, grid and scrolled widgets. Tix provides those. Good enough for my little application (more advanced and more modern widgets are available in frameworks like Qt, Gtk, or wxWindows). Before starting I spent some effort to find a) relevant documentation, b) GUI Builders which might help me, c) answers to non-obvious questions. The process took some time and effort so I want to share my findings: a) Documentation resources Python Docs http://docs.python.org/library/tkinter.html Tk Commands http://www.tcl.tk/man/tcl8.5/TkCmd/contents.htm Tix Reference http://tix.sourceforge.net/man/html/contents.htm Tix demo application You want to extract the Tix demo application coming with the Tix 8.4.3 source distribution. It contains examples for many widgets - unfortunately none for multi-column HList or the Grid (see below). https://sourceforge.net/project/showfiles.php?group_id=5649&package_id=5704 Tix8.4.3-src.tar.gz, then look in /Tix8.4.3/Python/Demo/tix Thinking in Tkinter I recommend the "Individual programs online" http://www.ferg.org/thinking_in_tkinter/index.html b) GUI development tools ActiveState GUI Builder (using grid layout) SpecTcl is the predecessor of GUI Builder (by ActivaState). http://spectcl.sourceforge.net/ FAQ (where to get source) http://aspn.activestate.com/ASPN/Mail/Message/komodo-announce/3355346 PAGE v3.0 by Stewart Allen (using placer layout) http://page.sourceforge.net/ There are many more for other GUI toolkits mentioned in this post: http://mail.python.org/pipermail/python-list/2004-February/250727.html Finally I decided to use the packer layout and create the widgets manually. Just the simplest and quickest way for me. c) How do I ...? How do I use all methods available in the Tix Grid? Tix Grid with full implementation of all methods http://klappnase.bubble.org/TixGrid/index.html How do I create a multi-column Tix.HList? import Tkinter as Tk import Tix root = Tix.Tk() # setup HList hl = Tix.HList(root, columns = 5, header = True) hl.header_create(0, text = "File") hl.header_create(1, text = "Date") hl.header_create(1, text = "Size") # create a multi-column row hl.add("row1", text = "filename.txt") hl.item_create(entry_path, 1, text = "2009-03-26 21:07:03") hl.item_create(entry_path, 2, text = "200MiB") I haven't found out how to right-justify individual columns? Anyone? How to implement Tk GUI with multiple threads? Usually there are two options to make threads wait for an event: * gui thread polling (lame) see here how to use Tk.after() (actually a Tcl command) to poll http://uucode.com/texts/pylongopgui/pyguiapp.html see here how to imitate the Tk event loop to poll for non-Tk events (a socket, for example) https://sourceforge.net/project/showfiles.php?group_id=5649&package_id=5704 Tix8.4.3-src.tar.gz, then look in /Tix8.4.3/Python/Demo/tix/ tixwidgets.py, find loop() * multithreaded with events (the option to choose) Basically this uses bind and event_generate to send "Notify" messages to the Tk instance. I suspect the following example failed due to not synchronising the event_generate call http://coding.derkeiler.com/Archive/Python/comp.lang.python/2006-07/msg0147… For multithreading Python Tk GUI applications the following rules apply: 1. same thread calling Tk must do all subsequent GUI calls, 2. other threads may send events with send_event to the root Tk instance, 3. with threading problems you might try to synchonise access to event_generate(). Using event_generate() with one non-GUI thread seems to be safe.

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Own network protocol
by pfranken85＠gmail.com Jan. 2, 2015

Jan. 2, 2015

Hello! I am just about setting up a project with an Raspberry Pi that is connected to some hardware via its GPIO pins. Reading the data already works perfectly but now I want to distribute it to clients running in the network. Hence, I have to setup a server in Python. I do not want to reinvent the wheel, so I am asking myself whether there is a good practice solution. It should basically work such that once value (can be either binary or an analog value) has changed on the server, it should send the update to the connected clients. At the same time, it should be possible for the client to send a particular request to the server as well, i.e., switch on LED X. What kind of protocol do you recommend for this? UDP or TCP? Do you recommend the use of frameworks such as twisted? Thanks for your input!

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Why For Loop Skips the Last element?
by Thuruv V Jan. 1, 2015

Jan. 1, 2015

Hi all, Here's the list. . inlist = ["Fossil Women's Natalie Stainless Steel Watch Brown (JR1385)", 'Balmer Swiss Made Veyron Mens Watch: Black Band/ Black Dial (62625241)', 'Fortune NYC Ladies Quilted Dial Watch: Brown', 'Jeanne Collection w/ Swarovski Elements Watch: Dark Purple Band (62623659)', 'Swiss Legend Commander Chronograph: Watch Orange/Black (SL-10067-01-ORS)', 'Debussy Ladies Watch: Brown/Gray/Silver 14070 - 62625292', '#2 Swiss Legend Commander Chronograph: Green (SL-10067-BB-017)', 'Auguste Jaccard 3 Timezone Watch: Black Band/ Gray & Black Dial (62625184)' ] My code : i = 0 while i <= len(inlist): if 'watch' in str(inlist[i]).lower() or 'watches' in str(inlist[i]).lower(): if 'women' in str(inlist[i]).lower() or 'female' in str(inlist[i]).lower() or 'ladies' in str(inlist[i]).lower(): print 'FEMale Watch', inlist.index(i),str(i) elif 'men' in str(inlist[i]).lower() or 'male' in str(inlist[i]).lower() or 'chronograph' in str(inlist[i]).lower(): print 'Male Watch',inlist.index(i),str(i) i = next(inlist) When on executing python skips the last element('Auguste Jaccard 3 Timezone Watch: Black Band/ Gray & Black Dial (62625184)') in the list. But when accessing through 'print inlist[0]' is possible,i.e it shows the e;lement. but the list skips it. . Please enlighten me. . Thanks.

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Multiprocessing process termination
by Charles Hixson Dec. 31, 2014

Dec. 31, 2014

In order to allow multiple processes to access a database (currently SQLite) I want to run the process in a separate thread. Because it will be accessed from multiple processes I intent to use Queues for shifting messages back and forth. But none of the individuals processes will know when all of the others are through. It there a way to properly close the database, or does it need to be done from the parent process? What I want to do is detect that a request to shutdown the Process has been received, and then execute a close procedure that cleans things up and shutdown. Terminate is the obvious procedure to use, but that comes with a warning not to use it if there is an queue attached (and without defining attached). OTOH, since the queue will never be read after the process has been shutdown, perhaps rendering it unusable is the proper thing. Could someone comment on this step of the design? The basic idea is: class handledb(Process): def __init__(self, q, otherstuff): self.q = q def run(self, msg): while (true): if self.q.empty(): sleep(someamountoftime) else: while (not self.q.empty()): read and parse message if message says to shutdown: self.shutdown() def shutdown(self): close things down ?? terminate ?? <<-- should this be done while q is live?

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numpy.fromiter in pypy
by Albert-Jan Roskam Dec. 31, 2014

Dec. 31, 2014

Hi, I would like to use numpy implementation for Pypy (what else would one do on December 31 :-). In particular, I would like to use numpy.fromiter, which is available according to this overview: http://buildbot.pypy.org/numpy-status/latest.html. However, contrary to what this website says, this function is not yet available. Conclusion: the website is wrong. Or am I missing something? albertjan@debian:~$ sudo pypy $(which pip) install -U git+https://bitbucket.org/pypy/numpy.git albertjan@debian:~$ sudo pypy -c 'import numpy' # sudo: as per the installation instructions albertjan@debian:~$ pypy Python 2.7.8 (f5dcc2477b97386c11e4b67f08a2d00fbd2fce5d, Sep 19 2014, 10:37:41) [PyPy 2.4.0 with GCC 4.8.2] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>>> import sys >>>> import numpy as np >>>> np.__version__, sys.version ('1.9.0', '2.7.8 (f5dcc2477b97386c11e4b67f08a2d00fbd2fce5d, Sep 19 2014, 10:37:41)\n[PyPy 2.4.0 with GCC 4.8.2]') >>>> np.fromiter <function tmp at 0x00007fdc06e35bc8> >>>> np.fromiter((i for i in range(10)), np.float) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/opt/pypy-2.4/site-packages/numpy/core/multiarray.py", line 55, in tmp raise NotImplementedError("%s not implemented yet" % func) NotImplementedError: fromiter not implemented yet Thanks in advance and happy 2015. Regards, Albert-Jan ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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Glade/Python - positioning main window at startup
by mbg1708＠planetmail.com Dec. 31, 2014

Dec. 31, 2014

Environment: Fedora 21, Linux 3.17.6, XFCE4 (with one workspace) Python: 2.7.8 Glade: 3.18.3 Background: the application window developed in Glade is (deliberately) somewhat smaller than the desktop. When the application starts, it starts offset from the center of the desktop. It looks as though the top left corner of the application window is centered in the desktop. Problem: Can anyone help me find settings (either in Glade or elsewhere) which will start the application window with the application window center aligned with the desktop center? Code Fragment: from gi.repository import Gtk import string import subprocess class AddressApp(object): def __init__(self): builder = Gtk.Builder() builder.add_from_file("mainwin.xml") builder.connect_signals(self) self.window = builder.get_object("window") self.lookup_name = builder.get_object("entry1") self.search_result = builder.get_object("treeview1") ....

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