🌐 Mailman 3 July 2011 - Python-list - python.org

How to receive a data file of unknown length using a python socket?
by twgray April 22, 2015

April 22, 2015

I am attempting to send a jpeg image file created on an embedded device over a wifi socket to a Python client running on a Linux pc (Ubuntu). All works well, except I don't know, on the pc client side, what the file size is? The following is a snippet: [code] f = open("frame.jpg",mode = 'wb') while True: data = self.s.recv(MAXPACKETLEN) if len(data) == 0: break recvd += len(data) f.write(data) f.close() [end] It appears to be locking up in 'data=self.s.recv(MAXPACKETLEN)' on the final packet, which will always be less than MAXPACKETLEN. I guess my question is, how do I detect end of data on the client side?

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Python newbie here! No module named settings
by Neeraj Agarwal April 13, 2015

April 13, 2015

Hello all, I'm a newbie to Python and its my 2nd day exploring it. I was trying to use Python wrapper for Google Charts API and was tweaking the examples. https://github.com/gak/pygooglechart/raw/master/examples/pie.py This is the script which I was trying. And the python interpreter gives the following error: import settings ImportError: No module named settings I installed Django as well before this (if its causing the problem, dunno) Please help me. Thanks, Neeraj

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Python to C++ in a pickle
by Larry Whitley April 2, 2015

April 2, 2015

I'd like to pickle an object in python and unpickle it in C++. The object in question is a python dictionary so it will have to go into a C++ map. Has someone done this and is willing to share? Or, is the cPickle source available on the web somewhere? Larry

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Re: feature request: a better str.endswith
by Irmen de Jong Feb. 17, 2015

Feb. 17, 2015

Jp Calderone wrote: > On Fri, Jul 18, 2003 at 05:01:47AM -0700, Michele Simionato wrote: > >>I often feel the need to extend the string method ".endswith" to tuple >>arguments, in such a way to automatically check for multiple endings. >>For instance, here is a typical use case: >> >>if filename.endswith(('.jpg','.jpeg','.gif','.png')): >> print "This is a valid image file" >> >>Currently this is not valid Python and I must use the ugly >> >>if filename.endswith('.jpg') or filename.endswith('.jpeg') \ >> or filename.endswith('.gif') or filename.endswith('.png'): >> print "This is a valid image file" > > > extensions = ('.jpg', '.jpeg', '.gif', '.png') > if filter(filename.endswith, extensions): > print "This is a valid image file > > Jp > Using filter Michele's original statement becomes: if filter(filename.endswith, ('.jpg','.jpeg','.gif','.png')): print "This is a valid image file" IMHO this is simple enough to not require a change to the .endswith method... --Irmen

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Re: drawing with the mouse with turtle
by Steven D'Aprano Feb. 10, 2015

Feb. 10, 2015

On Fri, 12 Nov 2010 19:24:50 -0500, Brian Blais wrote: > I'd like to draw on a turtle canvas, but use the mouse to direct the > turtle. I don't see a good way of getting the mouse coordinates and the > button state. I think the right way to do that is by creating an event handler to the turtle. These docs are for Python 2.7 turtle, but they may be applicable to older versions as well: http://docs.python.org/library/turtle.html#turtle.ondrag I quote: >>> turtle.ondrag(turtle.goto) Subsequently, clicking and dragging the Turtle will move it across the screen thereby producing handdrawings (if pen is down). That's probably all you need to do. -- Steven

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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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Creating interactive command-line Python app?
by planetthoughtful Dec. 18, 2014

Dec. 18, 2014

Hello All, Newbie to Python, and I'm wondering if it's possible to create a Python console app that prompts for further input on the command line when run (in Windows XP, if that's important)? I've tried Googling, but the results are overwhelmingly about interactive Python environments (IPython etc etc), instead of how to achieve prompting at the command line when running your own Python app. Any help appreciated! Much warmth, planetthoughtful

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Where is win32service
by catalinfest＠gmail.com Dec. 5, 2014

Dec. 5, 2014

I install Python 2.7 on Windows XP. I try use : import win32service import win32serviceutil But I got that error : ImportError: No module named win32service Where is this module ?

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Python docs disappointing
by kj Nov. 21, 2014

Nov. 21, 2014

I'm pretty new to Python, and I like a lot overall, but I find the documentation for Python rather poor, overall. I'm sure that Python experts don't have this problem: they have internalized some good ways to access the documentation, are productive with it, and therefore have lost the ability to see why the Python documentations is deficient for beginners. This explains why a suboptimal situation can persist like this: those who are most able fix it are also the least able to perceive it. I've heard similar complaints from other experienced programmers who are trying out Python for the first time: poor documentation. Here is an *entirely typical* example: on some Unix, try % pydoc urllib The displayed documentation mention the optional parameter "data" in practically every function listed (a few dozen of them). This parameter is not documented *anywhere* on that page. All that we are told is that its default value is always None. I'm sure that I can find a full description of this parameter if I fire up Google, and search online. In fact, more likely than not, I'll find far more documentation than I want. But my point is that a programmer should not need to do this. The full documentation should be readily accessible directly through a few keystrokes. I would love to know how experienced Python programmers quickly zero in on the Python documentation they need. TIA! kynn

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Twisted and txJSON-RPC
by writeson Nov. 14, 2014

Nov. 14, 2014

Hi all, I'm modifying a Twisted project and I'd like to implement the txJSON- RPC code show here: https://launchpad.net/txjsonrpc However, when I try to install this with this command line: sudo easy_install txJSON-RPC I get an error message: error: docs/PRELUDE.txt: No such file or directory I'm not sure what this is about, or how to fix it. Does anyone have any suggestions or help they can offer me? Thanks! Doug

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