ANN: Urwid 0.9.8 - Console UI Library
Announcing Urwid 0.9.8 -- Urwid home page: http://excess.org/urwid/ Tarball: http://excess.org/urwid/urwid-0.9.8.tar.gz About this release: === This release improves Urwid's performance by 70% to 450% (reducing running time by 41% to 82%)[1] for some benchmarks[2]. New base classes have been introduced for widgets, canvases and list walkers. Some bugs have been fixed. Python 2.2 or later is now required. There were three major changes that contributed to the performance improvement in this release. The Canvas class was rewritten so that canvases can be combined more efficiently. Canvas objects are now cached so that most unchanged widgets will not need to re-render themselves. There is a new C module for some of the heavily used low-level string functions contributed by Rebecca Breu. Urwid's raw_display module may now be used with libraries like Twisted that have their own event loops. Use the new get_input_descriptors() and get_input_nonblocking() methods instead of get_input() when using an external event loop. While I have tried to maintain compatibility with older versions of Urwid, some of the changes in this release may affect existing code. Please report any problems you have to the mailing list or the IRC channel. [1] http://article.gmane.org/gmane.comp.lib.urwid/415 [2] http://excess.org/urwid/browser/contrib/trunk New in this release: * Rendering is now significantly faster. * New Widget base class for all widgets. It includes automatic caching of rows() and render() methods. It also adds a new __super attribute for accessing methods in superclasses. Widgets must now call self._invalidate() to notify the cache when their content has changed. To disable caching in a widget set the class variable no_cache to a list that includes the string render. * Canvas classes have been reorganized: Canvas has been renamed to TextCanvas and Canvas is now the base class for all canvases. New canvas classes include BlankCanvas, SolidCanvas and CompositeCanvas. * External event loops may now be used with the raw_display module. The new methods get_input_descriptors() and get_input_nonblocking() should be used instead of get_input() to allow input processing without blocking. * The Columns, Pile and ListBox widgets now choose their first selectable child widget as the focus widget by defaut. * New ListWalker base class for list walker classes. * New Signals class that will be used to improve the existing event callbacks. Currently it is used for ListWalker objects to notify their ListBox when their content has changed. * SimpleListWalker now behaves as a list and supports all list operations. This class now detects when changes are made to the list and notifies the ListBox object. New code should use this class to wrap lists of widgets before passing them to the ListBox constructor. * New PollingListWalker class is now the default list walker that is used when passing a simple list to the ListBox constructor. This class is intended for backwards compatibility only. When this class is used the ListBox object is unable to cache its render() method. * The curses_display module can now draw in the lower-right corner of the screen. * All display modules now have start() and stop() methods that may be used instead of calling run_wrapper(). * The raw_display module now uses an alternate buffer so that the original screen can be restored on exit. The old behaviour is available by seting the alternate_buffer parameter of start() or run_wrapper() to False. * Many internal string processing functions have been rewritten in C to improve their performance. * Compatible with Python = 2.2. Python 2.1 is no longer supported. About Urwid === Urwid is a console UI library for Python. It features fluid interface resizing, UTF-8 support, multiple text layouts, simple attribute markup, powerful scrolling list boxes and flexible interface design. Urwid is released under the GNU LGPL. -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Unicode zipping from Python code?
Hi! As I experienced in the year 2006, the Python's zip module is not unicode-safe. With the hungarian filenames I got wrong result. I need to convert iso-8859-2 to cp852 chset to get good result. As I see, this module is a command line tool imported as extension. Now I search for something that can handle the characters good, or handle the unicode filenames. Does anyone knows about a python project that can do this? Or other tool what I can use for zipping intern. characters? Thanks for your help! dd -- http://mail.python.org/mailman/listinfo/python-list
cgi python
Hi Christian, I have seen your well-solved cgi-python answers. That's why I think you would be able to answer my query related to the same. I am writing a cgi program and placing it in cgi-bin folder of Apache Server. Now I have written a python script in the same folder to generate a graph 'genebarchart.py'. When I run this program from shell, i.e., C:\Program Files\Apache Group\Apache2\cgi-binpython genebarchart.py it runs well and creates the graph in htdocs folder as I save the graph there using a save command within the python script, but when I use the os.system command to call the python script within the cgi-code, i.e., os.system (python genebarchart.py) as both the scripts are in the same folder, it doesn't creates the graph in htdocs folder. Can u please tell me why? Thanks, Piyali -- http://mail.python.org/mailman/listinfo/python-list
Re: any ways to judge whether an object is initilized or not in a class
On 2007-03-20, Alex Martelli [EMAIL PROTECTED] wrote: Steven D'Aprano [EMAIL PROTECTED] wrote: ... There are plenty of reasons for preferring new style classes. If those reasons hold for you, then of course you should use new style classes. But that's not the same thing as saying that you should use new style classes *even when you don't care about those features*. You should always use new-style classes in order to avoid having to stop and make a decision each time you code a class -- having to stop and ask yourself do I need any of the many extra features of new-style classes here, or will legacy classes suffice? each and every time. There should ideally be only one obvious way -- and that obvious way is to always use new-style classes and avoid a feature that's there only for backwards compatibility with legacy code. I disagree. The obvious way is to use old-style classes. IMO the obvious way, is what a newbee will do after he has read the tutorial. And as far as I am familiar with the tutorial someone trying out python after he read it, will use old-style classes. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: Create new processes over telnet in XP
Shane Geiger a écrit : This reminds me of something I once wanted to do: How can I install Python in a totally non-gui way on Windows (without the use of VNC)? I think I was telnetted into a computer (or something like that) and I was unable to run the usual Python installer because it uses a GUI. Take a look at PortablePython, this may be the easy solution... http://www.portablepython.com/ A+ Laurent. -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending ECHO_REQUEST (pinging) with python
On Mar 26, 2007, at 1:30 AM, Thomas Dybdahl Ahle wrote: Hi, I've writing a python application in which I'd like to have a small ping label, to always tell the current ping time to the server. It seems however that I have to be root to send those imcp packages, but I guess there must be a workaround since I can easily use the ping command as ordinary user. Do anybody know how to do this in python? This won't solve your privileges issue, but this seems to get the ping time to server: import socket import os import sys import struct import time import select # Derived from ping.c distributed in Linux's netkit. That code is # copyright (c) 1989 by The Regents of the University of California. # That code is in turn derived from code written by Mike Muuss of the # US Army Ballistic Research Laboratory in December, 1983 and # placed in the public domain. They have my thanks. # Bugs are naturally mine. I'd be glad to hear about them. There are # certainly word-size dependenceies here. # Copyright (c) Matthew Dixon Cowles, http://www.visi.com/~mdc/. # Distributable under the terms of the GNU General Public License # version 2. Provided with no warranties of any sort. # Note that ICMP messages can only be sent from processes running # as root. # Revision history: # # November 22, 1997 # Initial hack. Doesn't do much, but rather than try to guess # what features I (or others) will want in the future, I've only # put in what I need now. # # December 16, 1997 # For some reason, the checksum bytes are in the wrong order when # this is run under Solaris 2.X for SPARC but it works right under # Linux x86. Since I don't know just what's wrong, I'll swap the # bytes always and then do an htons(). # # December 4, 2000 # Changed the struct.pack() calls to pack the checksum and ID as # unsigned. My thanks to Jerome Poincheval for the fix. # # From /usr/include/linux/icmp.h; your milage may vary. ICMP_ECHO_REQUEST = 8 # Seems to be the same on Solaris. # I'm not too confident that this is right but testing seems # to suggest that it gives the same answers as in_cksum in ping.c def checksum(str): csum = 0 countTo = (len(str) / 2) * 2 count = 0 while count countTo: thisVal = ord(str[count+1]) * 256 + ord(str[count]) csum = csum + thisVal csum = csum 0xL # Necessary? count = count + 2 if countTo len(str): csum = csum + ord(str[len(str) - 1]) csum = csum 0xL # Necessary? csum = (csum 16) + (csum 0x) csum = csum + (csum 16) answer = ~csum answer = answer 0x # Swap bytes. Bugger me if I know why. answer = answer 8 | (answer 8 0xff00) return answer def receiveOnePing(mySocket, ID, timeout): timeLeft = timeout while 1: startedSelect = time.time() whatReady = select.select([mySocket], [], [], timeLeft) howLongInSelect = (time.time() - startedSelect) if whatReady[0] == []: # Timeout return -1 timeReceived = time.time() recPacket, addr = mySocket.recvfrom(1024) icmpHeader = recPacket[20:28] typ, code, checksum, packetID, sequence = struct.unpack (bbHHh, icmpHeader) if packetID == ID: bytesInDouble = struct.calcsize(d) timeSent = struct.unpack(d, recPacket[28:28 + bytesInDouble])[0] return timeReceived - timeSent timeLeft = timeLeft - howLongInSelect if timeLeft = 0: return -1 def sendOnePing(mySocket, destAddr, ID): # Header is type (8), code (8), checksum (16), id (16), sequence (16) myChecksum = 0 # Make a dummy heder with a 0 checksum. header = struct.pack(bbHHh, ICMP_ECHO_REQUEST, 0, myChecksum, ID, 1) bytesInDouble = struct.calcsize(d) data = (192 - bytesInDouble) * Q data = struct.pack(d, time.time()) + data # Calculate the checksum on the data and the dummy header. myChecksum = checksum(header + data) # Now that we have the right checksum, we put that in. It's just easier # to make up a new header than to stuff it into the dummy. if sys.platform == 'darwin': myChecksum = socket.htons(myChecksum) 0x else: myChecksum = socket.htons(myChecksum) header = struct.pack(bbHHh, ICMP_ECHO_REQUEST, 0, myChecksum, ID, 1) packet = header + data mySocket.sendto(packet, (destAddr, 1)) # Don't know about the 1 def doOne(destAddr, timeout=10): # Returns either the delay (in seconds) or none on timeout. icmp = socket.getprotobyname(icmp) mySocket = socket.socket(socket.AF_INET,socket.SOCK_RAW,icmp) myID = os.getpid() 0x sendOnePing(mySocket, destAddr, myID) delay = receiveOnePing(mySocket, myID, timeout) mySocket.close() return delay def ping(host, timeout=1): dest = socket.gethostbyname(host) delay
Re: Create new processes over telnet in XP
Laurent Pointal wrote: Shane Geiger a écrit : This reminds me of something I once wanted to do: How can I install Python in a totally non-gui way on Windows (without the use of VNC)? I think I was telnetted into a computer (or something like that) and I was unable to run the usual Python installer because it uses a GUI. While I don't remember if I've actually tried it you should be able to do this with WMI. Example here... http://timgolden.me.uk/python/wmi_cookbook.html#install-a-product If I have time to do it (and then undo whatever damage it does ;) I'll give it a go later. TJG -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending ECHO_REQUEST (pinging) with python
On Mar 26, 2007, at 1:30 AM, Thomas Dybdahl Ahle wrote: It seems however that I have to be root to send those imcp packages, but I guess there must be a workaround since I can easily use the ping command as ordinary user. The workaround your ping command is using btw, is probably running suid root. hth, Michael --- Simplicity is the ultimate sophistication. -Leonardo da Vinci -- http://mail.python.org/mailman/listinfo/python-list
Calling Queue experts
I have a script which is based on the following code. Unfortunately,
it only works on Python 2.3 and not 2.5 because there is no esema or
fsema attribute in the 2.5 Queue. I am hunting through the Queue.py
code now to try to figure out how to make it work in 2.5, but as I am
a beginner, I am having difficulty and would appreciate your help.
Many thanks
Jon
import os
import Queue
import threading
import time
import cPickle
class PickleQueue(Queue.Queue):
A multi-producer, multi-consumer, persistent queue.
def __init__(self, filename, maxsize=0):
Initialize a persistent queue with a filename and maximum
size.
The filename is used as a persistent data store for the
queue.
If maxsize = 0, the queue size is infinite.
self.filename = filename
Queue.Queue.__init__(self, maxsize)
if self.queue:
self.esema.release()
if self._full():
self.fsema.acquire()
def _init(self, maxsize):
# Implements Queue protocol _init for persistent queue.
# Sets up the pickle files.
self.maxsize = maxsize
try:
self.readfile = file(self.filename, 'r')
self.queue = cPickle.load(self.readfile)
self.readfile.close()
except IOError, err:
if err.errno == 2:
# File doesn't exist, continue ...
self.queue = []
else:
# Some other I/O problem, reraise error
raise err
except EOFError:
# File was null? Continue ...
self.queue = []
# Rewrite file, so it's created if it doesn't exist,
# and raises an exception now if we aren't allowed
self.writefile = file(self.filename, 'w')
cPickle.dump(self.queue, self.writefile, 1)
def __sync(self):
# Writes the queue to the pickle file.
self.writefile.seek(0)
cPickle.dump(self.queue, self.writefile, 1)
self.writefile.flush()
def _put(self, item):
# Implements Queue protocol _put for persistent queue.
self.queue.append(item)
self.__sync()
def _get(self):
# Implements Queue protocol _get for persistent queue.
item = self.queue[0]
del self.queue[0]
self.__sync()
return item
class counterThread(threading.Thread):
numberQueue = PickleQueue('/export/home/jrpf/data.pkl')
exitCounterQueue = Queue.Queue(1)
def run(self):
command = ''
i = 0
while 1:
self.numberQueue.put(i)
if i 10:
print i 10 so attempting to exit
wt.exit()
self.exit()
print i
try:
command = self.exitCounterQueue.get(block=False)
except Queue.Empty:
pass
if command == 'exit':
print Counter thread exited
break
i = i + 1
time.sleep(1)
def exit(self):
self.exitCounterQueue.put('exit')
def main():
ct = counterThread()
ct.setDaemon(True)
ct.start()
ct.join()
if __name__ == __main__:
main()
--
http://mail.python.org/mailman/listinfo/python-list
Re: Pattern for foo tool - API - shell|GUI
On Sunday 25 March 2007 16:44, Steven Bethard wrote: Anastasios Hatzis wrote: I'm working on a tool which is totally command-line based and consisting of multiple scripts. The user can execute a Python script in the shell, this script does some basic verification before delegating a call into my tool's package and depending on some arguments and options provided in the command-line, e.g. $python generate.py myproject --force --verbose the tool processes whatever necessary. There are multiple command handlers available in this package which are responsible for different tasks and depending of the script that has been executed one or more of these command handlers are fired to do their work ;) Side note: you might find argparse (http://argparse.python-hosting.com/) makes this a bit easier if you have positional arguments or sub-commands:: Steve, thank you, for the note. I didn't know argparse before. I have multiple scripts since optparse puts all arguments and options into one single help text, and the arguments and options are too specific for most commands (and thus the help would be absolutely overloaded and useless for new users). It seems that argparse has multiple help pages separated for each sub-command, as far as I understand the page. And I don't think that this is very trivial (at least not for my programming skill level). In the given example generate.py (above) the following scenario is pretty likely: (1) User works with UML tool and clicks in some dialog a generate button (2) UML tool triggers this event an calls a magic generate() method of my tool (via the API I provide for this purpose), like my generate.py script would do same way (3) Somewhen with-in this generate process my tool may need to get some information from the user in order to continue (it is in the nature of the features that I can't avoid this need of interaction in any case). So you're imagining an API something like:: def generate(name, force=False, verbose=False, handler=command_line_handler): ... choice = handler.prompt_user(question_text, user_choices) ... where the command-line handler might look something like:: class CommandLineHandler(object): ... def prompt_user(self, question_text, user_choices): while True: choice = raw_input(question_text) if choice in user_choices: return choice print 'invalid choice, choose from %s' % choices and the GUI client would implement the equivalent thing with dialogs? Exactly. - Now, as I see your example, I wonder if this would work with a GUI which is event-driven... I have to look into my wx GUI prototype. That seems basically reasonable to me, though you should be clear in the documentation of generate() -- and any other methods that accept handler objects -- exactly what methods the handler must provide. You also may find that prompt_user is a bit too generic -- e.g. a file chooser dialog looks a lot different from a color chooser dialog -- so you may need to split this up into prompt_user_file, prompt_user_color, etc. so that handler's don't have to introspect the question text to know what to do... STeVe Hey, right, good idea. I didn't think about the different task-specific dialogs in most GUIs. But I see that usability will gain benefit from differentiated prompt methods. Anastasios -- http://mail.python.org/mailman/listinfo/python-list
Re: Create new processes over telnet in XP
Tim Golden wrote: Laurent Pointal wrote: Shane Geiger a écrit : This reminds me of something I once wanted to do: How can I install Python in a totally non-gui way on Windows (without the use of VNC)? I think I was telnetted into a computer (or something like that) and I was unable to run the usual Python installer because it uses a GUI. While I don't remember if I've actually tried it you should be able to do this with WMI. Example here... http://timgolden.me.uk/python/wmi_cookbook.html#install-a-product If I have time to do it (and then undo whatever damage it does ;) I'll give it a go later. TJG Or, indeed, just run it in quiet mode, according to the docs: http://www.python.org/download/releases/2.5/msi/ TJG -- http://mail.python.org/mailman/listinfo/python-list
Re: problem at installing phyton on windows
Obviously, Phyton will never be defined. Indeed I remember in the climactic showdown between Phyton and the rest of the gamma ranger FooDroids and he kept doing the mega kick move. and I was thinking wow Phyton will never be defined, he will just keep kicking ass. I hear they're gonna make a Phyton Commandant movie. Cheers, Bryan Rasmussen -- http://mail.python.org/mailman/listinfo/python-list
Re: A better webpage filter
John J. Lee wrote: http://webcleaner.sourceforge.net/ Thanks, I will look into it sometime. Essentially my problem has been solved by switching to opera, but old habits die hard and I find myself using Mozilla and my little script more often than would be logical. Maybe the idea of having a *Python* script open at all times to which all content goes through is just too tempting. I mean if there's some possible irritation on a site theoretically I could just write a specific function to get rid of it. This mental setting works as a placebo on my web browsing experience so that the actual problems don't always even need to be solved ... I hope I'm not losing all traditional programmers here in this approach :-) Not actually tried it myself, though did browse some of the code once or twice -- does some clever stuff. Lots of other Python-implemented HTTP proxies, some of which are relevant (though AFAIK all less sophisticated than webcleaner), are listed on Alan Kennedy's nice page here: http://xhaus.com/alan/python/proxies.html A surprising amount of diversity there. At least now I know what general category seems to be nearest to my solution so thanks again for that. However my solution is not really doing anything like the programs on this page (although it is related to removing ads), instead it tries to modulate a copy of the page after it's been saved on disk. This removes all kinds of links and enables one to definitely and finally reshape the form the page will take. As such it is more concerned with the metaphysical image the page makes on the users brain and less with the actual content or the security aspects. One thing I noticed though on that (nice!) Alan Kennedy page is that there was a script that was so small that it didn't even have a homepage but instead it just relied on a google groups post! I guess you can see that I liked that one :-) My filter is even smaller. I've tried to make it smaller still by removing the batch file and using webbrowser.open(some cStringIO object) but that didn't work on windows. regards, A. -- http://mail.python.org/mailman/listinfo/python-list
Grid and scrollbars
Hi, I am trying to build my own IHM with two treeCtrl and 1 grid, based on the wx.aui demos. My problem is with the Grid. It dosen't have scrollbars. I tried many methods (fit) but it always fail. Can somebody point me where is the mistake ? Thx #!/usr/bin/env python # -*- coding: utf-8 -*- import wx import wx.aui import wx.grid import wx.html import sys,os import images # stuff for debugging print wx.version:, wx.version() print pid:, os.getpid() ##raw_input(Press Enter...) assertMode = wx.PYAPP_ASSERT_DIALOG ##assertMode = wx.PYAPP_ASSERT_EXCEPTION text = \ Hello World! TXT overview = \ htmlbody h3Hello World ! HTML/h3 /body/html class MyFrame(wx.Frame): def __init__(self, parent, id=-1, title='wx.aui Test', size=(1024, 768), style=wx.DEFAULT_FRAME_STYLE): wx.Frame.__init__(self, parent, id, title, (0,0), size, style) self._mgr = wx.aui.AuiManager(self) self.data = [[1010, The foo doesn't bar, major, 1, 'MSW', 1, 1, 1, 1.12], [1011, I've got a wicket in my wocket, wish list, 2, 'other', 0, 0, 0, 1.50], [1012, Rectangle() returns a triangle, critical, 5, 'all', 0, 0, 0, 1.56] ] self.grid = CustTableGrid(self, self.data) mb = wx.MenuBar() file_menu = wx.Menu() file_menu.Append(wx.ID_EXIT, Exit) mb.Append(file_menu, File) self.SetMenuBar(mb) self.statusbar = self.CreateStatusBar(2, wx.ST_SIZEGRIP) self.statusbar.SetStatusWidths([-2, -3]) self.statusbar.SetStatusText(Ready, 0) self.statusbar.SetStatusText(Welcome To wxPython!, 1) tb2 = wx.ToolBar(self, -1, wx.DefaultPosition, wx.DefaultSize, wx.TB_FLAT | wx.TB_NODIVIDER) tb2.SetToolBitmapSize(wx.Size(16,16)) tb2_bmp1 = wx.ArtProvider_GetBitmap(wx.ART_QUESTION, wx.ART_OTHER, wx.Size(16, 16)) tb2.AddLabelTool(101, Test, tb2_bmp1) tb2.AddLabelTool(101, Test, tb2_bmp1) tb2.AddLabelTool(101, Test, tb2_bmp1) tb2.AddLabelTool(101, Test, tb2_bmp1) tb2.AddSeparator() tb2.AddLabelTool(101, Test, tb2_bmp1) tb2.AddLabelTool(101, Test, tb2_bmp1) tb2.Realize() #Toolbar self._mgr.AddPane(tb2, wx.aui.AuiPaneInfo(). Name(tb2).Caption(Toolbar 2). ToolbarPane().Top().Row(1). LeftDockable(False).RightDockable(False)) #Grid self._mgr.AddPane(self.grid, wx.aui.AuiPaneInfo(). Name(Matrice).Caption(Matrice). Center().Layer(1).Position(1).CloseButton(True).MaximizeButton(True)) #Tree Left self._mgr.AddPane(self.CreateTreeCtrl(), wx.aui.AuiPaneInfo(). Name(Q).Caption(Tree Pane). Left().Layer(1).Position(1).CloseButton(True).MaximizeButton(True)) #Tree Right self._mgr.AddPane(self.CreateTreeCtrl(), wx.aui.AuiPaneInfo(). Name(Quest).Caption(Tree Pane). Right().Layer(1).Position(1).CloseButton(True).MaximizeButton(True)) self._mgr.Update() self.Bind(wx.EVT_CLOSE, self.OnClose) self.Bind(wx.EVT_MENU, self.OnClose, id=wx.ID_EXIT) def CreateTreeCtrl(self): tree = wx.TreeCtrl(self, -1, wx.Point(0, 0), wx.Size(160, 250), wx.TR_DEFAULT_STYLE | wx.NO_BORDER) root = tree.AddRoot(Root) items = [] imglist = wx.ImageList(16, 16, True, 2) imglist.Add(wx.ArtProvider_GetBitmap(wx.ART_FOLDER, wx.ART_OTHER, wx.Size(16,16))) imglist.Add(wx.ArtProvider_GetBitmap(wx.ART_NORMAL_FILE, wx.ART_OTHER, wx.Size(16,16))) tree.AssignImageList(imglist) tree.AppendItem(root, Root, 1) items.append(tree.AppendItem(root, Item 1, 0)) items.append(tree.AppendItem(root, Item 2, 0)) items.append(tree.AppendItem(root, Item 3, 0)) items.append(tree.AppendItem(root, Item 4, 0)) items.append(tree.AppendItem(root, Item 5, 0)) for ii in xrange(len(items)): id = items[ii] tree.AppendItem(id, Subitem 1, 1) tree.AppendItem(id, Subitem 2, 1) tree.AppendItem(id, Subitem 3, 1) tree.AppendItem(id, Subitem 4, 1) tree.AppendItem(id, Subitem 5, 1) tree.Expand(root) return tree def CreateHTMLCtrl(self): ctrl = wx.html.HtmlWindow(self, -1, wx.DefaultPosition, wx.Size(400, 300)) if gtk2 in wx.PlatformInfo: ctrl.SetStandardFonts() ctrl.SetPage(self.GetIntroText()) return ctrl def GetIntroText(self): return overview def OnClose(self, event): # deinitialize the frame manager self._mgr.UnInit() # delete the frame self.Destroy() class CustomDataTable(wx.grid.PyGridTableBase):
Re: detect suprocess interaction
Robin Becker [EMAIL PROTECTED] wrote: I'm using subprocess to carry out svn commands (probably should use the svn api package, but that's a dependency too far). Anyhow my code looks like from subprocess import Popen, PIPE p = Popen((svn,'ls',u),stdout=PIPE,stderr=PIPE) i = p.wait() and this sort of thing works well under most circumstances. However, when this code is executed for the very first time by a particular user it hangs waiting on user input. This code is being used purely for testing correctness of a particular svn url so in the normal case we want to throw away both stdout and stderr. In the exceptional case is it possible to detect that input is required and only in that case issue the current contents of stdout (presumably a request for a password)? Clearly I need to supply some kind of input filelike object, but is this sort of thing possible. Yes it is possible, but if you try it you'll find you'll need to implement the fileno() method of file objects which is asked to return an OS file handle. This is obviously a problem! In general subprocess isn't really designed for interactive processes like the above. You'll find it much easier to use pexpect for interactive stuff. Note that svn has its own devious ways of finding a terminal to ask the user for the password, eg... $ svn ls svn+ssh://[EMAIL PROTECTED]/svn /dev/null /dev/null 21 Password: I don't know exactly how it does that but I suspect it is to do with the controlling terminal... On my system $ setsid svn ls svn+ssh://[EMAIL PROTECTED]/svn /dev/null /dev/null 21 Pops up a gui box asking for the password! You can simulate the above with Popen(..., stdin=file(os.devnull,r), preexec_fn=os.setsid) -- Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
Re: Python object overhead?
Matt Garman a écrit :
I'm trying to use Python to work with large pipe ('|') delimited data
files.
Looks like a job for the csv module (in the standard lib).
The files range in size from 25 MB to 200 MB.
Since each line corresponds to a record, what I'm trying to do is
create an object from each record. However, it seems that doing this
causes the memory overhead to go up two or three times.
See the two examples below: running each on the same input file
results in 3x the memory usage for Example 2. (Memory usage is
checked using top.)
Just for the record, *everything* in Python is an object - so the
problem is not about 'using objects'. Now Of course, a complex object
might eat up more space than a simple one...
Python has 2 simple types for structured data : tuples (like database
rows), and dicts (associative arrays). You can use the csv module to
parse a csv-like format into either tuples or dicts. If you want to save
memory, tuples may be the best choice.
This happens for both Python 2.4.3 on Gentoo Linux (64bit) and Python
2.3.4 on CentOS 4.4 (64bit).
Is this just the way it is or am I overlooking something obvious?
What are you doing with your records ? Do you *really* need to keep the
whole list in memory ? Else you can just work line by line:
source = open(sys.argv[1])
for line in source:
do_something_with(line)
source.close()
This will avoid building a huge in-memory list.
While we're at it, your snippets are definitively unpythonic and
overcomplicated:
(snip)
filedata = list()
file = open(sys.argv[1])
while True:
line = file.readline()
if len(line) == 0: break # EOF
filedata.append(line)
file.close()
(snip)
filedata = open(sys.argv[1]).readlines())
Example 2: read lines into objects:
# begin readobjects.py
import sys, time
class FileRecord:
class FileRecord(object):
def __init__(self, line):
self.line = line
If this is your real code, I don't see any reason why this should eat up
3 times more space than the original version.
records = list()
file = open(sys.argv[1])
while True:
line = file.readline()
if len(line) == 0: break # EOF
rec = FileRecord(line)
records.append(rec)
file.close()
records = map(FileRecord, open(sys.argv[1]).readlines()))
--
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Re: Python object overhead?
Felipe Almeida Lessa a écrit : On 3/23/07, Bjoern Schliessmann [EMAIL PROTECTED] wrote: (Note that almost everything in Python is an object!) Could you tell me what in Python isn't an object? statements and expressions ?-) -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending ECHO_REQUEST (pinging) with python
On Mon, Mar 26, 2007 at 08:30:16AM +0200, Thomas Dybdahl Ahle wrote: Hi, I've writing a python application in which I'd like to have a small ping label, to always tell the current ping time to the server. It seems however that I have to be root to send those imcp packages, but I guess there must be a workaround since I can easily use the ping command as ordinary user. Do anybody know how to do this in python? You need root for that and the ping command is allowed to have them by suid bit. You can execute ping from inside python and use ping as is, if you need. -- This is a terroristic email. It will explode in 10 minutes, if you do not close it in the meantime. Michal vorner Vaner pgpGCsSHtsxLl.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: creating jsp-like tool with python
jd a écrit : I'd like to create a program that takes files with jsp-like markup and processes the embedded code (which would be python) to produce the output file. There would be two kinds of sections in the markup file: python code to be evaluated, and python code that returns a value that would be inserted into the output. This seems like it would be straightforward in python, and maybe there's even a library that I could use for this, but as a newbie to Python, I don't know the landscape very well. I am not looking for a big framework, just something small and simple that will do just this job. Suggestions or pointers would be greatly appreciated. There are already quite a few Python templating solutions. You may want to look for: - Python server pages - Mighty - Mako - Jinja - Genshi - Cheetah - Newov - Zope Page Templates - SimpleTAL (standalone implementation of ZPT) - (add your favorite Python templating system here) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python object overhead?
Bruno Desthuilliers a écrit : Matt Garman a écrit : (snip) class FileRecord(object): def __init__(self, line): self.line = line If this is your real code, I don't see any reason why this should eat up 3 times more space than the original version. Hem... Forget about this comment - not enough coffein yet I'm afraid. -- http://mail.python.org/mailman/listinfo/python-list
Re: Calling Queue experts
Got it. New PickleQueue class should be as follows: import Queue import cPickle class PickleQueue(Queue.Queue): A multi-producer, multi-consumer, persistent queue. def __init__(self, filename, maxsize=0): Initialize a persistent queue with a filename and maximum size. The filename is used as a persistent data store for the queue. If maxsize = 0, the queue size is infinite. self.filename = filename Queue.Queue.__init__(self, maxsize) print self.queue def _init(self, maxsize): # Implements Queue protocol _init for persistent queue. # Sets up the pickle files. self.maxsize = maxsize try: self.readfile = file(self.filename, 'r') self.queue = cPickle.load(self.readfile) self.readfile.close() except IOError, err: if err.errno == 2: # File doesn't exist, continue ... self.queue = Queue.deque() else: # Some other I/O problem, reraise error raise err except EOFError: # File was null? Continue ... self.queue = Queue.deque() # Rewrite file, so it's created if it doesn't exist, # and raises an exception now if we aren't allowed self.writefile = file(self.filename, 'w') cPickle.dump(self.queue, self.writefile, 1) def __sync(self): # Writes the queue to the pickle file. self.writefile.seek(0) cPickle.dump(self.queue, self.writefile, 1) self.writefile.flush() def _put(self, item): # Implements Queue protocol _put for persistent queue. self.queue.append(item) self.__sync() def _get(self): # Implements Queue protocol _get for persistent queue. item = self.queue.popleft() self.__sync() return item -- http://mail.python.org/mailman/listinfo/python-list
with timeout(...):
Did anyone write a contextmanager implementing a timeout for python2.5? I'd love to be able to write something like with timeout(5.0) as exceeded: some_long_running_stuff() if exceeded: print Oops - took too long! And have it work reliably and in a cross platform way! From my experiments with timeouts I suspect it won't be possible to implement it perfectly in python 2.5 - maybe we could add some extra core infrastructure to Python 3k to make it possible? -- Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
Re: with timeout(...):
Nick Craig-Wood wrote: Did anyone write a contextmanager implementing a timeout for python2.5? I'd love to be able to write something like with timeout(5.0) as exceeded: some_long_running_stuff() if exceeded: print Oops - took too long! And have it work reliably and in a cross platform way! From my experiments with timeouts I suspect it won't be possible to implement it perfectly in python 2.5 - maybe we could add some extra core infrastructure to Python 3k to make it possible? I'm guessing your question is far over my head, but if I understand it, I'll take a stab: First, did you want the timeout to kill the long running stuff? I'm not sure if its exactly what you are looking for, but I wrote a timer class that does something like you describe: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/464959 Probably you can do whatever you want upon timeout by passing the appropriate function as the expire argument. This works like a screen saver, etc. James -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help to learn Python
wesley chun [EMAIL PROTECTED] writes: with that said, i would still like to state that the book's target audience is for people who know how to program but need to pick up Python as quickly as possible. the theory that's in the book is really more explanation of how the Python interpreter works, especially the relationship between objects and memory management. the goal is to give you enough of an understanding of how Python works under the covers that you will write very effective code, even as a beginner to the language. Worked for me. The 1/e was the easiest intro to a language I've ever read. (I don't suppose you fancy doing one for Ruby :) Eddie -- http://mail.python.org/mailman/listinfo/python-list
Re: functions, classes, bound, unbound?
7stud a écrit : ...classes don't invoke the function directly, they convert it to an 'unbound method' object:: (snip) If you really want to get to the original function, there are a couple of options. No. Just trying to figure out how some things work. Most of Python's object model is documented here: http://www.python.org/download/releases/2.2.3/descrintro/ http://users.rcn.com/python/download/Descriptor.htm HTH -- http://mail.python.org/mailman/listinfo/python-list
Re: Other classes in a module
Daniel Nogradi a écrit : Can an instance of a class in a module, in any simple way find out which other classes that exists in said module ? # module x ## class c1: pass class c2: pass ### Python 2.5 (r25:51908, Nov 1 2006, 11:42:37) [GCC 3.4.2 20041017 (Red Hat 3.4.2-6.fc3)] on linux2 Type help, copyright, credits or license for more information. import types import x for i in dir(x): ... if type(getattr(x,i)) is types.ClassType: ... print Hey, '%s' is a class! % i ... Hey, 'c1' is a class! Hey, 'c2' is a class! It might be not exactly what you want but maybe still helps. Doesn't work with new-style classes: class Foo(object): pass ... import typs Traceback (most recent call last): File stdin, line 1, in ? ImportError: No module named typs import types type(Foo) is types.ClassType False -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending ECHO_REQUEST (pinging) with python
Michael Bentley [EMAIL PROTECTED] wrote: On Mar 26, 2007, at 1:30 AM, Thomas Dybdahl Ahle wrote: It seems however that I have to be root to send those imcp packages, but I guess there must be a workaround since I can easily use the ping command as ordinary user. The workaround your ping command is using btw, is probably running suid root. Under linux the only priviledge you need is CAP_NET_RAW. It is possible to give this to a process - a bit of searching with google will show you how! -- Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
Re: the second of nested buttons using textvariable remains void!
Thanks a lot Jim and James now it works fine! Sam -- http://mail.python.org/mailman/listinfo/python-list
Re: python on window
i have written this program but i have gott following error,
in anather proram indentation error sir how i will indent in my
editor
#test.py
def invert(table):
index=()
for key in table:
value=table[key]
if not index.has_key(value):
index[value]=[]
index[value].append(key)
return index
phonebook = {'sandeep':9325, 'amit':9822, 'anand':9890, 'titu': 9325}
phonebook
{'titu': 9325, 'amit': 9822, 'anand': 9890, 'sandeep': 9325}
print phonebook
{'titu': 9325, 'amit': 9822, 'anand': 9890, 'sandeep': 9325}
inverted_phonebook = invert(phonebook)
Traceback (most recent call last):
File pyshell#13, line 1, in module
inverted_phonebook = invert(phonebook)
File pyshell#9, line 5, in invert
if not index.has_key(value):
AttributeError: 'tuple' object has no attribute 'has_key'
interted_phonebook= invert(phonebook)
Traceback (most recent call last):
File pyshell#14, line 1, in module
interted_phonebook= invert(phonebook)
File pyshell#9, line 5, in invert
if not index.has_key(value):
AttributeError: 'tuple' object has no attribute 'has_key'
--
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Re: with timeout(...):
Nick Craig-Wood wrote: Did anyone write a contextmanager implementing a timeout for python2.5? I'd love to be able to write something like with timeout(5.0) as exceeded: some_long_running_stuff() if exceeded: print Oops - took too long! And have it work reliably and in a cross platform way! Cross platform isn't the issue here - reliability though is. To put it simple: can't be done that way. You could of course add a timer to the python bytecode core, that would jump back to a stored savepoint or something like that. But to make that work reliably, it has to be ensured that no sideeffects occur while being in some_long_running_stuff. which doesn't only extend to python itself, but also external modules and systems (file writing, network communications...). Which can't be done, unless you use a time-machine. Which I'd take as an personal insult, because in that rolled-back timeframe I will be possibly proposing to my future wife or something... Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: python on window
On 26 Mar 2007 05:00:54 -0700, sandeep patil [EMAIL PROTECTED] wrote:
i have written this program but i have gott following error,
in anather proram indentation error sir how i will indent in my
editor
#test.py
def invert(table):
index=()
for key in table:
value=table[key]
if not index.has_key(value):
index[value]=[]
index[value].append(key)
return index
phonebook = {'sandeep':9325, 'amit':9822, 'anand':9890, 'titu': 9325}
phonebook
{'titu': 9325, 'amit': 9822, 'anand': 9890, 'sandeep': 9325}
print phonebook
{'titu': 9325, 'amit': 9822, 'anand': 9890, 'sandeep': 9325}
inverted_phonebook = invert(phonebook)
Traceback (most recent call last):
File pyshell#13, line 1, in module
inverted_phonebook = invert(phonebook)
File pyshell#9, line 5, in invert
if not index.has_key(value):
AttributeError: 'tuple' object has no attribute 'has_key'
interted_phonebook= invert(phonebook)
Traceback (most recent call last):
File pyshell#14, line 1, in module
interted_phonebook= invert(phonebook)
File pyshell#9, line 5, in invert
if not index.has_key(value):
AttributeError: 'tuple' object has no attribute 'has_key'
In your code, index = () means it is a tuple. IIRC, it should be a
dictionary. For that, index = {}. This is the one causing the following
error in your code,
if not index.has_key(value):
AttributeError: 'tuple' object has no attribute 'has_key'
You can not use has_key over a tuple object.
But where is the indentation error ? I see nothing like that in the error
message.
--
With Regards
---
Parthan.S.R.
--
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Re: Calling Queue experts
jrpfinch # Some other I/O problem, reraise error jrpfinch raise err I'd just execute a bare raise (without err). That way the caller gets the stack trace of the actual IOError. Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: A better webpage filter
En Mon, 26 Mar 2007 06:06:00 -0300, Anton Vredegoor [EMAIL PROTECTED] escribió: Thanks, I will look into it sometime. Essentially my problem has been solved by switching to opera, but old habits die hard and I find myself using Mozilla and my little script more often than would be logical. Maybe the idea of having a *Python* script open at all times to which all content goes through is just too tempting. I mean if there's some possible irritation on a site theoretically I could just write a specific function to get rid of it. This mental setting works as a If you don't mind using JavaScript instead of Python, UserJS is for you: http://www.opera.com/support/tutorials/userjs/ -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: with timeout(...):
On Mar 26, 3:16 pm, Diez B. Roggisch [EMAIL PROTECTED] wrote: But to make that work reliably, it has to be ensured that no sideeffects occur while being in some_long_running_stuff. which doesn't only extend to python itself, but also external modules and systems (file writing, network communications...). Which can't be done, unless you use a time-machine. Hey hey, isn't the Python mantra that we're all adults here? It'd be the programmers responsibility to use only code that has no side effects. I certainly can ensure that no side-effects occur in the following code: 1+2. I didn't even need a time machine to do that :P Or the primitive could be implemented so that Python throws a TimeoutException at the earliest opportunity. Then one could write except-blocks which deal with rolling back any undesirable side effects. (I'm not saying such timeout feature could be implemented in Python, but it could be made by modifying the CPython implementation) -- http://mail.python.org/mailman/listinfo/python-list
Re: Calling Queue experts
En Mon, 26 Mar 2007 07:29:32 -0300, jrpfinch [EMAIL PROTECTED] escribió: Got it. New PickleQueue class should be as follows: Only a comment: def _init(self, maxsize): # Implements Queue protocol _init for persistent queue. # Sets up the pickle files. self.maxsize = maxsize try: self.readfile = file(self.filename, 'r') self.queue = cPickle.load(self.readfile) self.readfile.close() except IOError, err: if err.errno == 2: # File doesn't exist, continue ... self.queue = Queue.deque() else: # Some other I/O problem, reraise error raise err except EOFError: # File was null? Continue ... self.queue = Queue.deque() # Rewrite file, so it's created if it doesn't exist, # and raises an exception now if we aren't allowed self.writefile = file(self.filename, 'w') cPickle.dump(self.queue, self.writefile, 1) self.readfile may be left open in case of error, I'd use a try/finally. And since it isn't used anywhere, I'd just use a local variable instead of an instance attribute. And the final write is not necesary when you have just read it - and alters the last-modified-time (that may not be relevant for you, of course, but as a general tool it may confuse other users). -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: python on window
On Mar 26, 2007, at 7:00 AM, sandeep patil wrote:
i have written this program but i have gott following error,
in anather proram indentation error sir how i will indent in my
editor
#test.py
def invert(table):
index=()
for key in table:
value=table[key]
if not index.has_key(value):
index[value]=[]
index[value].append(key)
return index
phonebook = {'sandeep':9325, 'amit':9822, 'anand':9890, 'titu':
9325}
phonebook
{'titu': 9325, 'amit': 9822, 'anand': 9890, 'sandeep': 9325}
print phonebook
{'titu': 9325, 'amit': 9822, 'anand': 9890, 'sandeep': 9325}
inverted_phonebook = invert(phonebook)
Traceback (most recent call last):
File pyshell#13, line 1, in module
inverted_phonebook = invert(phonebook)
File pyshell#9, line 5, in invert
if not index.has_key(value):
AttributeError: 'tuple' object has no attribute 'has_key'
If you define index as a dict instead of a tuple, you'll stop getting
that error -- but I'm afraid it still won't do what you want. Are
you trying to get a phonebook in which the values of the original
phonebook are the keys of the new one -- and the values are lists
(both 'sandeep' and 'titu' have the same number)? If so, try this:
def invert(table):
index=dict()
for k,v in table.items():
if index.has_key(v):
index[v].append(k)
else:
index[v] = [k]
return index
You had mentioned something about indentation error... If you'll
look at your definition of invert(), you can see that 'return index'
is inside the for loop -- which would cause a return before the
second time through the for loop. By dedenting (is that a word?) so
'return' falls directly below 'for', the for loop would have been
able to run to completion before returning.
Hope this helps,
Michael
---
Our network was brought down by a biscuit??? --Steven D'Aprano
--
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osx tkinter listbox problem
I am using Darwin 10.4.9, tcl 8.4.7, tk 8.4, and python 2.3.5. I have also tried Python 2.5 on Darwin, Debian, and Fedora Core 6. I am working on a GUI front-end to a Python program of mine. It is a simple grid with labels in the left column and input widgets in the right column. One of the rows has a listbox in the right column. The listbox contains two items. I select one using widget.select_set(). The GUI is not complete yet, because I am still learning about Python and Tkinter. On Linux, the GUI works as expected. On OSX, when select_set() runs, the listbox disappears from its place in the grid, and appears in the upper left corner of the window. Here are screen shots to illustrate. http://terrorpin.net/~ben/docs/alt/music/soundfont/pysf-wip/pysfi-debian.jpg http://terrorpin.net/~ben/docs/alt/music/soundfont/pysf-wip/pysfi-osx.png The GUI code itself is at the following location. http://terrorpin.net/~ben/docs/alt/music/soundfont/pysf-wip/pysfi.py To run, it needs the Python program at the following location. http://terrorpin.net/~ben/docs/alt/music/soundfont/pysf-wip/pysf.py Why does the listbox change position at all? Am I using listbox incorrectly? Thank you, Ben -- http://mail.python.org/mailman/listinfo/python-list
Fortran vs Python - Newbie Question
OK... I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Thanks Chris -- http://mail.python.org/mailman/listinfo/python-list
Zip file writing progress (callback proc)
Hi! I want to check my zip file writings. I need some callback procedure to show a progress bar. Can I do that? I don't want to modify the PyLib module to extend it, because if I get another py, the changes are lost. This happening too if I copy the zip module to modify it. Any solution? Thanks for it: dd -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On 26 Mar 2007 06:20:32 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are Python is hugely easier to read. quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level Fortran is massively faster than Python. language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On Mar 26, 8:20 am, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Thanks Chris While I have never personally dealt with Fortran, I looked it up here: http://en.wikipedia.org/wiki/Fortran_code_examples The code examples speak for themselves. I recommend you look those over and then look over similar simple program written in Python. Python is still easier to read. Fortran also appears to be a compiled language, whereas Python is an interpreted language. Thus, Python programs can be tested faster. Fortran programs will likely run faster though. Check out www.python.org for good examples of Python code for the beginner and the advanced programmer. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On Mar 26, 9:20 am, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Thanks Chris The standard way is to perform the number crunching in Fortran and to use Python as glue. See for instance the scipy project, which includes the f2py bridge. Michele Simionato -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On Mar 26, 3:20 pm, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Portability, scalability RAD. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On Mar 26, 2:42 pm, Jean-Paul Calderone [EMAIL PROTECTED] wrote: On 26 Mar 2007 06:20:32 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are Python is hugely easier to read. quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level Fortran is massively faster than Python. language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. Can you back this up with some source?? Chris -- http://mail.python.org/mailman/listinfo/python-list
web development with python - comparison
Here is a comprehensive review of python web apps: http://jesusphreak.infogami.com/blog/vrp1 Since this comes up every so often in this group. i. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On 26 Mar 2007 06:47:18 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: On Mar 26, 2:42 pm, Jean-Paul Calderone [EMAIL PROTECTED] wrote: On 26 Mar 2007 06:20:32 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are Python is hugely easier to read. quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level Fortran is massively faster than Python. language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. Can you back this up with some source?? Half the code in Numeric was compiled from fortran. Need I go on? :) Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. Can you back this up with some source?? Chris Is this really the most important issue in your choice ? As said by others, Portability, scalability RAD as an advantage of Python are probably far more important. And on the other hand Python is perfect as glue between Fortran and whatsoever. To emphasize that, I expect the number of lines in Python is at least 3 times less than in Fortran. I did some comparison between MatLab and Python (Scipy) for real-time analysis, and for all my cases Pyhton van 3 .. 7 times faster than MatLab. So I'ld suggest to start with downloading the Enthought edition of Python, and you can judge for yourself within 10 minutes, if it's fast enough. cheers, Stef Mientki -- http://mail.python.org/mailman/listinfo/python-list
Re: To count number of quadruplets with sum = 0
FWIW, the original program can also be compiled with Shed Skin (http:// mark.dufour.googlepages.com), an experimental (static-)Python-to-C++ compiler, resulting in a speedup of about 8 times for a single test with 500 tuples. here's a slightly modified version that works with Shed Skin CVS at least: after optimizing dicts a bit for Shedskin 0.0.21 (http:// mark.dufour.googlepages.com), the speedup for this program is now about 16.5 times for the same test. Thanks, Mark Dufour (Shed Skin author - send me bug reports!) -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On 26 Mar, 14:20, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: what are the advantages of using Python for creating number crunching apps over Fortran?? If you have to ask, you've not experienced enough Fortran to know its sheer horror. You can write programs in Python that do usefully complicated things, and you can get them to work in a reasonable time. Fortran can't do this, for anything more than the trivial. Classic Fortran tasks of the past are now seen as trivial. OK, so they did it to a lot of data, but they really didn't do anything very complex to it. You can also write Python that other people can read and maintain. You can't do this in Fortran, without a truly insane amount of trouble. As Fortran programs have historically been authored and hacked on by successive generations of grad students, this is the most vital feature of all. Finally we're no longer so interested in number crunching. Number crunching used to consist of simple operations over vast arrays of data, although this was data with remarkably simple structure by today's standards. These just aren't the major class of problems of interest today. There's a massive difference between old-school FEA (bashing Newton and Hooke into tinier and tinier cells) and bioinformatics or anything involving the representation of big data graphs. Python is a tad slower than Fortran If the Fortran program turns out to have been broken all along, then who cares? -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On 26 Mar, 15:06, stef [EMAIL PROTECTED] wrote: You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. Can you back this up with some source?? Chris Is this really the most important issue in your choice ? As said by others, Portability, scalability RAD as an advantage of Python are probably far more important. And on the other hand Python is perfect as glue between Fortran and whatsoever. To emphasize that, I expect the number of lines in Python is at least 3 times less than in Fortran. I did some comparison between MatLab and Python (Scipy) for real-time analysis, and for all my cases Pyhton van 3 .. 7 times faster than MatLab. So I'ld suggest to start with downloading the Enthought edition of Python, and you can judge for yourself within 10 minutes, if it's fast enough. cheers, Stef Mientki Is there a mac version?? Thanks Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On Mar 26, 4:47 pm, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. Can you back this up with some source?? Chris If you execute one command in Python which tells a super-optimized Fortran-routine to do lots of work, the overhead of Python will be neglible. That's all there is to it, no need for a source. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
[EMAIL PROTECTED] [EMAIL PROTECTED] wrote: ... So I'ld suggest to start with downloading the Enthought edition of Python, and you can judge for yourself within 10 minutes, if it's fast enough. cheers, Stef Mientki Is there a mac version?? http://download.enthought.com/MacEnthon/ReadMe.html but it's self labeled as 0.1 Test Release i.e. somewhat preliminary; it claims to support only Panther (10.3) and its 2.3.0 Python (no claims for Tiger, 10.4, and its 2.3.5 Python, nor for other Python Mac istalls yet). If you're just trying to learn and check things out, it might be better to get a more recent Python from python.org (2.5 or 2.4.4) and the various other packages as and when you need them (you can use the MacEnthon list as a guide:-). You'll need a C compiler to be sure you can install any package from sources -- Apple's XCode includes gcc, it's free, and it's the safest choice (but it's a HUGE download, as it comes with a lot of stuff -- I don't think Apple offers a simple way to install just gcc and minimal supporting tools). Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: A better webpage filter
Gabriel Genellina wrote: If you don't mind using JavaScript instead of Python, UserJS is for you: http://www.opera.com/support/tutorials/userjs/ My script loads a saved copy of a page and uses it to open an extra tab with a filtered view. It also works when javascript is disabled. A. -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending ECHO_REQUEST (pinging) with python
Den Mon, 26 Mar 2007 11:24:34 +0200 skrev Michal 'vorner' Vaner: On Mon, Mar 26, 2007 at 08:30:16AM +0200, Thomas Dybdahl Ahle wrote: Do anybody know how to do this in python? You need root for that and the ping command is allowed to have them by suid bit. You can execute ping from inside python and use ping as is, if you need. Yeah, I could execute ping, but it would lock me harder to the platform. -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending ECHO_REQUEST (pinging) with python
Den Mon, 26 Mar 2007 06:30:04 -0500 skrev Nick Craig-Wood: Michael Bentley [EMAIL PROTECTED] wrote: On Mar 26, 2007, at 1:30 AM, Thomas Dybdahl Ahle wrote: It seems however that I have to be root to send those imcp packages, but I guess there must be a workaround since I can easily use the ping command as ordinary user. The workaround your ping command is using btw, is probably running suid root. Under linux the only priviledge you need is CAP_NET_RAW. It is possible to give this to a process - a bit of searching with google will show you how! How, I did google, but I wasn't able to find any way to do this in python.. -- http://mail.python.org/mailman/listinfo/python-list
Re: Zip file writing progress (callback proc)
On Mar 26, 4:41 pm, durumdara [EMAIL PROTECTED] wrote: Hi! I want to check my zip file writings. I need some callback procedure to show a progress bar. Can I do that? I don't want to modify the PyLib module to extend it, because if I get another py, the changes are lost. This happening too if I copy the zip module to modify it. Any solution? Thanks for it: dd Would it be enough to show progress based on how many files have been added to the zip? If you're zipping just one huge file, I'm afraid you can't get a progress bar using the zipfile module. If it's not necessary that the one file is a zip but simply compressed, you can use zlib or bz2 modules to compress incrementally: http://www.python.org/doc/lib/node303.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending ECHO_REQUEST (pinging) with python
On Mon, 26 Mar 2007 16:50:33 +0200, Thomas Dybdahl Ahle [EMAIL PROTECTED] wrote: Den Mon, 26 Mar 2007 06:30:04 -0500 skrev Nick Craig-Wood: Michael Bentley [EMAIL PROTECTED] wrote: On Mar 26, 2007, at 1:30 AM, Thomas Dybdahl Ahle wrote: It seems however that I have to be root to send those imcp packages, but I guess there must be a workaround since I can easily use the ping command as ordinary user. The workaround your ping command is using btw, is probably running suid root. Under linux the only priviledge you need is CAP_NET_RAW. It is possible to give this to a process - a bit of searching with google will show you how! How, I did google, but I wasn't able to find any way to do this in python.. You need a sendmsg wrapper (there are several, none in the stdlib), then you need a privileged process which is willing to give you the privilege. It's pretty inconvenient. Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
In article [EMAIL PROTECTED], Jean-Paul Calderone [EMAIL PROTECTED] wrote: On 26 Mar 2007 06:20:32 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are Python is hugely easier to read. quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level Fortran is massively faster than Python. language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. Jean-Paul Me, too. A lot of language questions are correctly answered, Indistinguishable, to within the range of subjective response. This is NOT the case for the readability and performance of Fortran and Python, though; the differences are as massive as Jean-Paul says. HOWEVER, that's all true only in general. As a new- comer to both Fortran and Python, there's a fair chance that the Fortran code you first produce would be so suboptimal as to perform no better than the corresponding Python. My vote, therefore, is this: unless you're in an organization that provides a lot of Fortran support to such beginners as yourself, choose Python. It has all the pertinent advantages. We can discuss secondary concerns at more length, if you wish: Python's better suited than Fortran for a range of other applications you might wish to tackle some day; Python originated from a language- for-beginners project, and truly is something you can start to pick up in a day; your own scientific specialty might be one that's particularly well- endowed with an existing body of code written in Fortran (or Python, or C++, or ...); and so on. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python object overhead?
On 3/23/07, Bjoern Schliessmann [EMAIL PROTECTED] wrote: one blank line == EOF? That's strange. Intended? In my case, I know my input data doesn't have any blank lines. However, I'm glad you (and others) clarified the issue, because I wasn't aware of the better methods for checking for EOF. Example 2: read lines into objects: # begin readobjects.py import sys, time class FileRecord: def __init__(self, line): self.line = line What's this class intended to do? Store a line :) I just wanted to post two runnable examples. So the above class's real intention is just to be a (contrived) example. In the program I actually wrote, my class structure was a bit more interesting. After storing the input line, I'd then call split(|) (to tokenize the line). Each token would then be assigned to an member variable. Some of the member variables turned into ints or floats as well. My input data had three record types; all had a few common attributes. So I created a parent class and three child classes. Also, many folks have suggested operating on only one line at a time (i.e. not storing the whole data set). Unfortunately, I'm constantly looking forward and backward in the record set while I process the data (i.e., to process any particular record, I sometimes need to know the whole contents of the file). (This is purchased proprietary vendor data that needs to be converted into our own internal format.) Finally, for what it's worth: the total run time memory requirements of my program is roughly 20x the datafile size. A 200MB file literally requires 4GB of RAM to effectively process. Note that, in addition to the class structure I defined above, I also create two caches of all the data (two dicts with different keys from the collection of objects). This is necessary to ensure the program runs in a semi-reasonable amount of time. Thanks to all for your input and suggestions. I received many more responses than I expected! Matt -- http://mail.python.org/mailman/listinfo/python-list
Re: Python object overhead?
On 3/23/07, Jack Diederich [EMAIL PROTECTED] wrote: If you make the record a new style class (inherit from object) you can specify the __slots__ attribute on the class. This eliminates the per instance dictionary overhead in exchange for less flexibility. When you say new style class, do you mean that the __slots__ feature is only available in a newer version of Python? Unfortunately, I'm stuck on 2.3.4 for this project. Thanks, Matt -- http://mail.python.org/mailman/listinfo/python-list
calling class instances and their methods
hi, i created an instance of a my own class which has methods and all. now i get an outside function called, which is unfortunatly not aware of the instace at all (i don't control how this outside function is called). but i would like to get access back to my instance and it's methods. is there any clean way of doing this ? thanks in advance -- http://mail.python.org/mailman/listinfo/python-list
wx.grid problem
Hi ! I have a small problem with wx.Grid and scrollbars. Scrollbars definitively dissapears after resizing the frame. Thx for help #-- import wx,wx.grid #-- class MainWindow(wx.Frame): def __init__(self,parent,id,title): wx.Frame.__init__(self,parent,wx.ID_ANY,title) #-- self.grid= wx.grid.Grid(id=wx.ID_ANY,parent=self) self.grid.CreateGrid(numRows=10,numCols=2) self.grid.Fit() self.Fit() #-- self.Show(1) #-- app = wx.PySimpleApp() frame=MainWindow(None,-1,'Grid sizer') app.MainLoop() del app -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On 26 Mar 2007 06:20:32 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Thanks Chris Dear Chris, Why are you focusing on Python vs. Fortran? There might be other choices out there you might want to consider, specifically C, O'Caml, and Ada, since you mention number crunching. When choosing, you should consider what other requirements you'll have; some people have hinted at a few, such as portability (I am not saying fortrain ain't portable) and rapid application development. Will you be doing lots of string manipulation? Processing text-files? Gluing applications? What do people around you use? What type of number crunching will you be doing? Are the libraries available in any of the languages that you are considering that do some/most of what you want to do? Are you concernded about concurrent/distributed programming? Is this your first programming language? Etc, etc, etc. In the end, maybe neither Python nor Fortran might be the best choices for you. HTH, R. -- http://mail.python.org/mailman/listinfo/python-list -- Ramon Diaz-Uriarte Statistical Computing Team Structural Biology and Biocomputing Programme Spanish National Cancer Centre (CNIO) http://ligarto.org/rdiaz -- http://mail.python.org/mailman/listinfo/python-list
Re: Python object overhead?
On Mon, 26 Mar 2007 09:13:58 -0600, Matt Garman [EMAIL PROTECTED] wrote: On 3/23/07, Jack Diederich [EMAIL PROTECTED] wrote: If you make the record a new style class (inherit from object) you can specify the __slots__ attribute on the class. This eliminates the per instance dictionary overhead in exchange for less flexibility. When you say new style class, do you mean that the __slots__ feature is only available in a newer version of Python? Unfortunately, I'm stuck on 2.3.4 for this project. A new-style class is one which has a type of type instead of ClassType. For example: class notnewstyle: ... pass ... type(notnewstyle) type 'classobj' class newstyle(object): ... pass ... type(newstyle) type 'type' class alsonewstyle(list): ... pass ... type(alsonewstyle) type 'type' 2.3 has new-style classes. Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On Mar 26, 10:11 am, Andy Dingley [EMAIL PROTECTED] wrote: On 26 Mar, 14:20, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: what are the advantages of using Python for creating number crunching apps over Fortran?? If you have to ask, you've not experienced enough Fortran to know its sheer horror. You can write programs in Python that do usefully complicated things, and you can get them to work in a reasonable time. Fortran can't do this, for anything more than the trivial. Classic Fortran tasks of the past are now seen as trivial. OK, so they did it to a lot of data, but they really didn't do anything very complex to it. You couldn't be more incorrect. I have run some very old (pre-Fortran 77) programs that are very far from trivial. You can also write Python that other people can read and maintain. You can't do this in Fortran, without a truly insane amount of trouble. This is a lie. I've seen some Fortran code that was hellspawned, and some that was clear as glass. The latter came about without a truly insane amount of trouble. As Fortran programs have historically been authored and hacked on by successive generations of grad students, this is the most vital feature of all. Perhaps this is your impression because it's the only Fortran code you've ever been exposed to? Finally we're no longer so interested in number crunching. Number crunching used to consist of simple operations over vast arrays of data, although this was data with remarkably simple structure by today's standards. These just aren't the major class of problems of interest today. I suspect you're speaking from a narrow perspective, because number crunching, as you define it, is still a problem of interest and heavily researched. Maybe it's not in your field. Anyways, you seem to be ignorant of the complexities of simple operations over vast arrays, as if it you could accomplish these operations with a few lines of Python and numpy. That might be true for your homework, but good number-crunching codes often did a lot of stuff under the covers. There's a massive difference between old-school FEA (bashing Newton and Hooke into tinier and tinier cells) and bioinformatics or anything involving the representation of big data graphs. Ok, but exactly how do bioinformatics or big data graphs help you determine the stress profile in a beam? Python is a tad slower than Fortran If the Fortran program turns out to have been broken all along, then who cares? That Fortran code is inherently broken is a pretty asinine thing to suggest. No one's under the impression that Fortran is a great, all- purpose language like Python is, but it does what it was designed to do well. When faced with a numerical problem, it's reasonable to consider using Fortran (especially knowing you can interface it with Python). Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: Python object overhead?
On Mar 26, 12:13 pm, Matt Garman [EMAIL PROTECTED] wrote: On 3/23/07, Jack Diederich [EMAIL PROTECTED] wrote: If you make the record a new style class (inherit from object) you can specify the __slots__ attribute on the class. This eliminates the per instance dictionary overhead in exchange for less flexibility. When you say new style class, do you mean that the __slots__ feature is only available in a newer version of Python? Unfortunately, I'm stuck on 2.3.4 for this project. new style classes are available since Python 2.2. You declare a new- style class just by inheriting from object. Among other things, they have properties, and the above menctioned __slots__ optimization. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On Mar 26, 3:20 pm, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Fortran may be faster, but Python (with NumPy and SciPy) is often fast enough. A lot of practitioners use Matlab, which is often slower than Python. Matplotlib is an excellent Python extension for graphing data. Anyone serious about numerical computing should learn Fortran 95. But use it sparsely and only where its needed. Fortran is perfect for numerical work but useless for anything else. Usually the amount of code that will benefit from using Fortran over NumPy makes up less than a percent of the line count. You can call Fortran from Python using f2py, so you can get the best from both worlds. -- http://mail.python.org/mailman/listinfo/python-list
Re: calling class instances and their methods
On Mar 26, 12:00 pm, spohle [EMAIL PROTECTED] wrote: i created an instance of a my own class which has methods and all. now i get an outside function called, which is unfortunatly not aware of the instace at all (i don't control how this outside function is called). but i would like to get access back to my instance and it's methods. I don't understand well. Do you want to call a method on your object, from inside that external function? Can you modify its code? -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
PMW widget - skip tabbing to it
I have multiple PMW widgets (EntryFields, ScrolledField etc), how can I skip over these widgets when using the tab key? Thank you, John -- http://mail.python.org/mailman/listinfo/python-list
Kill thread or at least socket.getaddrinfo
Hi, I'm writing an application that connects to the internet. Something like this: for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM): af, socktype, proto, canonname, sa = res try: self.sock = socket.socket(af, socktype, proto) Now if the user press the cancel button, I'd like the connection to imidiatly stop. I run self.sock.shutdown(socket.SHUT_RDWR) self.sock.close() Dunno if they are both nessesary. I normaly use only the first, but it makes no difference to use both. If python is at the actual connection in socket.socket( this work fine, but if python is at calling socket.getaddrinfo(, it doesn't stop. I also can't kill the thread, as it is afaik not a possibility in python. Is there any other way to do this? -- http://mail.python.org/mailman/listinfo/python-list
Re: calling class instances and their methods
spohle [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] hi, i created an instance of a my own class which has methods and all. now i get an outside function called, which is unfortunatly not aware of the instace at all (i don't control how this outside function is called). but i would like to get access back to my instance and it's methods. is there any clean way of doing this ? thanks in advance Ummm... I'm not exactly sure what you mean by an outside function, but let's refer to that function as f(). Are you saying you want to re-implement f() to use your new object but don't want to (or can't) change calls to f()? If so, then you can either use a global reference to your new object if it is the sort of thing you want to keep around between invocations of f() (i.e., create your object somewhere and then save in a scope that f() can access). Otherwise, you can simply instantiate your object inside of f() as a local variable and use it. If you mean something else, I guess you will have to clarify. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
[EMAIL PROTECTED] a écrit : On Mar 26, 8:20 am, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Thanks Chris While I have never personally dealt with Fortran, I looked it up here: http://en.wikipedia.org/wiki/Fortran_code_examples The code examples speak for themselves. I recommend you look those over and then look over similar simple program written in Python. Python is still easier to read. Fortran also appears to be a compiled language, whereas Python is an interpreted language. Being 'compiled' or 'interpreted' is not a feature of a language, but of a given implementation of a language (and even then, some implementations of some languages supports both). wrt/ CPython (the reference implementation), it is actually compiled to byte-code - just like Java. The main difference being that the VM is smart enough to automagically (re)compile what's needed. -- http://mail.python.org/mailman/listinfo/python-list
Re: wx.grid problem
On Mar 26, 10:20 am, BH [EMAIL PROTECTED] wrote: Hi ! I have a small problem with wx.Grid and scrollbars. Scrollbars definitively dissapears after resizing the frame. Thx for help #-- import wx,wx.grid #-- class MainWindow(wx.Frame): def __init__(self,parent,id,title): wx.Frame.__init__(self,parent,wx.ID_ANY,title) #-- self.grid= wx.grid.Grid(id=wx.ID_ANY,parent=self) self.grid.CreateGrid(numRows=10,numCols=2) self.grid.Fit() self.Fit() #-- self.Show(1) #-- app = wx.PySimpleApp() frame=MainWindow(None,-1,'Grid sizer') app.MainLoop() del app If I understand this correctly, that is normal. Your grid is only two columns by 10 rows, so if you resize your frame so that it shows all rows and columns, the scroll bars will disappear, much like other apps, such as FireFox. If you enlarge the frame enough, the scrollbars go away. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
In article [EMAIL PROTECTED], [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: . . . You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. Can you back this up with some source?? Chris Yes. While evidence in computing science is ... well, the standards aren't well established; still, I think you'll want to start with URL: http://www.sciencemag.org/cgi/content/abstract/279/5356/1525 . This describes a supercomputer simulation that won awards in the '90s for its performance. The application itself is basically what Jean-Paul recommended: Python, with high-performance libraries written in C, C++, and Fortran. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
In article [EMAIL PROTECTED], [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: . . . Is there a mac version?? Thanks Chris Yes. Several, in fact--all available at no charge. The Python world is different from what experience with Fortran might lead you to expect. I'll be more clear: Fortran itself is a distinguished language with many meritorious implementations. It can be costly, though, finding the implementation you want/need for any specific environment. Python, in contrast, is blessed with a plethora of implementations and variations, all of which are available without licensing fee. In particular, recent Mac OS X installations INCLUDE Python--it's already in there! -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
In article [EMAIL PROTECTED], Alex Martelli [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: ... So I'ld suggest to start with downloading the Enthought edition of Python, and you can judge for yourself within 10 minutes, if it's fast enough. cheers, Stef Mientki Is there a mac version?? http://download.enthought.com/MacEnthon/ReadMe.html but it's self labeled as 0.1 Test Release i.e. somewhat preliminary; it claims to support only Panther (10.3) and its 2.3.0 Python (no claims for Tiger, 10.4, and its 2.3.5 Python, nor for other Python Mac istalls yet). If you're just trying to learn and check things out, it might be better to get a more recent Python from python.org (2.5 or 2.4.4) and the various other packages as and when you need them (you can use the MacEnthon list as a guide:-). You'll need a C compiler to be sure you can install any package from sources -- Apple's XCode includes gcc, it's free, and it's the safest choice (but it's a HUGE download, as it comes with a lot of stuff -- I don't think Apple offers a simple way to install just gcc and minimal supporting tools). Alex Yes and no. Alex, while useful scientific computing under Mac OS X will almost certainly eventually involve installation of XCode and so on, Nomad.C can start to learn Python without a need to install ANYTHING. As you know, Python is already there, and the version that comes with 10.4 (2.3.5, as nearly as I can easily tell) is easily adequate to take him through the Tutorial (with minor exceptions). Also, while I, like you, am aware of no minimal-gcc package from Apple, I think third parties make it available. However, I'm not motivated enough at this point to track down the details. I think Nomad.C should start with what he has under 10.4, and plan to move on later to all of XCode. -- http://mail.python.org/mailman/listinfo/python-list
Re: call to function by text variable
In article [EMAIL PROTECTED],
Steve Holden [EMAIL PROTECTED] wrote:
Cameron Laird wrote:
In article [EMAIL PROTECTED],
Jan Schilleman [EMAIL PROTECTED] wrote:
Hi,
try this:
func = getattr(operations, [Replace, ChangeCase, Move][n])
HTH,
Jan
ianaré [EMAIL PROTECTED] schreef in bericht
news:[EMAIL PROTECTED]
yeah the subject doesn't really make sense does it?
anyway want I want to do is this:
if n == 1:
self.operations.insert(pos, operations.Replace.Panel(self, main))
.
.
.
I think you meant ...[n - 1] rather than ...[n].
I'm a tiny bit surprised no one has organized this in terms
of a dictionary. I don't know, of course, how robust is the
characterization of n as a small integer. Maybe
lookup_table = {
0: Replace,
1: ChangeCase,
2: Move}
captures the sentiment; maybe something else does it better.
Surely for this requirement the *only* advantage of a dictionary over a
list is its ability to index with arbitrary values and thereby avoid the
need to use [n-1]. Wouldn't it therefore be less perverse to use
lookup_table = {
1: Replace,
2: ChangeCase,
3: Move}
Of course the dictionary would be a big win if the integer choice values
weren't a linear sequence. Otherwise using a list with a fixed offset is
likely to be quicker.
.
.
.
Ugh. Yes.
Maybe your question, Wouldn't it therefore be less perverse ...?,
was rhetorical. I feel obliged to answer in public, though, rather
than sending the private e-mail I originally wrote, because I want
to leave no doubt in the minds of readers of this thread: what I
wrote was wrong. Yes, Steve's lookup_table binding (or assignment)
was what I had in mind all along, and entirely superior to what I
mistakenly wrote; my thanks to him. He also elaborated the correct
detail: if the integer choice values weren't a linear sequence,
or if they weren't even integers, or ..., then the dictionary
suddenly becomes much more compelling.
Incidentally, a fair amount of Python code that looks like
if n == 1:
...
elif n == 2:
...
turns out, in my experience, to have been inherited from some other
language in such a way that it turns out n is not even the most
natural or expressive determinant. A fully idiomatic rewriting will
have a table where the keys are more-humanly-readable strings, rather
than small integers.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Kill thread or at least socket.getaddrinfo
On Mar 26, 10:53 am, Thomas Dybdahl Ahle [EMAIL PROTECTED] wrote: Hi, I'm writing an application that connects to the internet. Something like this: for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM): af, socktype, proto, canonname, sa = res try: self.sock = socket.socket(af, socktype, proto) Now if the user press the cancel button, I'd like the connection to imidiatly stop. I run self.sock.shutdown(socket.SHUT_RDWR) self.sock.close() Dunno if they are both nessesary. I normaly use only the first, but it makes no difference to use both. If python is at the actual connection in socket.socket( this work fine, but if python is at calling socket.getaddrinfo(, it doesn't stop. I also can't kill the thread, as it is afaik not a possibility in python. Is there any other way to do this? This is addressed to some degree on a wxPython wiki at: http://wiki.wxpython.org/index.cgi/LongRunningTasks I think you can also use the join() method. I've also heard that if you know the pid, you can kill it, but that's not always a clean way of accomplishing the task. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: How to find tag to /tag HTML strings and 'save' them?
John Nagle [EMAIL PROTECTED] wrote:
htags = soup.findAll({'h2':True, 'H2' : True}) # get all H2 tags,
both cases
Have you been bitten by this? When I read this, I was operating under
the assumption that BeautifulSoup wasn't case sensitive, and then I
tried this:
import BeautifulSoup as BS
soup=BS.BeautifulSoup('bone/bBtwo/B')
soup.findAll('b')
[bone/b, btwo/b]
soup.findAll({'b':True})
[bone/b, btwo/b]
So I am a little curious.
max
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Re: Python object overhead?
Matt Garman a écrit : (snip) Also, many folks have suggested operating on only one line at a time (i.e. not storing the whole data set). Unfortunately, I'm constantly looking forward and backward in the record set while I process the data (i.e., to process any particular record, I sometimes need to know the whole contents of the file). (This is purchased proprietary vendor data that needs to be converted into our own internal format.) Don't know if this could solve your problem, but have considered using an intermediate (preferably embedded) SQL database (something like SQLite) ? -- http://mail.python.org/mailman/listinfo/python-list
Re: functions, classes, bound, unbound?
On Mar 25, 3:09 pm, Steven Bethard [EMAIL PROTECTED] wrote: Here's another way of looking at it:: class Test(object): ... pass ... def greet(): ... print 'Hello' ... Test.greet = greet Test.greet unbound method Test.greet Interesting. After playing around with that example a bit and finally thinking I understood bound v. unbound, I found what appears to be an anomaly: class Test(object): pass def greet(x): print hello Test.func = greet print Test.func t = Test() print t.func def sayBye(x): print bye t.bye = sayBye print t.bye output: unbound method Test.greet bound method Test.greet of __main__.Test object at 0x6dc50 function sayBye at 0x624b0 Why doesn't t.bye cause a method object to be created? ... under the covers, classes are actually using doing something like this:: Test.__dict__['greet'].__get__(None, Test) unbound method Test.greet Test.greet == Test.__dict__['greet'].__get__(None, Test) True ...via __getattribute_, right? ... if you want to get a method from a function, you can always do that manually yourself:: greet.__get__(None, Test) unbound method Test.greet Manually creating a method object. Nice. -- http://mail.python.org/mailman/listinfo/python-list
Re: PMW widget - skip tabbing to it
On Mar 26, 10:51 am, jp [EMAIL PROTECTED] wrote: I have multiple PMW widgets (EntryFields, ScrolledField etc), how can I skip over these widgets when using the tab key? Thank you, John I would probably write some custom event handling. Something that could tell it was a key-press event and not just an on-focus event. Then it would be a simple, if key-press == tab, put focus on next widget of interest. Something like that should work. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
Alex Martelli wrote: [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: ... So I'ld suggest to start with downloading the Enthought edition of Python, and you can judge for yourself within 10 minutes, if it's fast enough. cheers, Stef Mientki Is there a mac version?? http://download.enthought.com/MacEnthon/ReadMe.html but it's self labeled as 0.1 Test Release i.e. somewhat preliminary; it claims to support only Panther (10.3) and its 2.3.0 Python (no claims for Tiger, 10.4, and its 2.3.5 Python, nor for other Python Mac istalls yet). It no longer exists, in fact. I don't know why the readme still exists, too. If you're just trying to learn and check things out, it might be better to get a more recent Python from python.org (2.5 or 2.4.4) and the various other packages as and when you need them (you can use the MacEnthon list as a guide:-). You'll need a C compiler to be sure you can install any package from sources -- Apple's XCode includes gcc, it's free, and it's the safest choice (but it's a HUGE download, as it comes with a lot of stuff -- I don't think Apple offers a simple way to install just gcc and minimal supporting tools). Here are some more instructions for building the usual suspects: numpy, scipy, VTK, PIL, ipython, matplotlib. https://svn.enthought.com/enthought/wiki/IntelMacPython25 -- Robert Kern I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: PMW widget - skip tabbing to it
On Mar 26, 11:17 am, [EMAIL PROTECTED] wrote: On Mar 26, 10:51 am, jp [EMAIL PROTECTED] wrote: I have multiple PMW widgets (EntryFields, ScrolledField etc), how can I skip over these widgets when using the tab key? Thank you, John I would probably write some custom event handling. Something that could tell it was a key-press event and not just an on-focus event. Then it would be a simple, if key-press == tab, put focus on next widget of interest. Something like that should work. Mike I looked in my Tkinter book, and it says that if the widget has the takefocus option set to true, the widget is placed in the tab group and will get focus when they are tabbed to. I assume that this means if you set the PMW widgets' takefocus option to false, they will be skipped over since they won't be in the tab group. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: PMW widget - skip tabbing to it
On Mar 26, 11:17 am, [EMAIL PROTECTED] wrote: On Mar 26, 10:51 am, jp [EMAIL PROTECTED] wrote: I have multiple PMW widgets (EntryFields, ScrolledField etc), how can I skip over these widgets when using the tab key? Thank you, John I would probably write some custom event handling. Something that could tell it was a key-press event and not just an on-focus event. Then it would be a simple, if key-press == tab, put focus on next widget of interest. Something like that should work. Mike Isn't there just a simple configuration option to disable the tab key? Like the takfocus option with Tkinter widgets? -- http://mail.python.org/mailman/listinfo/python-list
Re: wx.grid problem
Yes, absolutely, but try to minimize it, and the scrollbars stays hidden !!! [EMAIL PROTECTED] a écrit : On Mar 26, 10:20 am, BH [EMAIL PROTECTED] wrote: Hi ! I have a small problem with wx.Grid and scrollbars. Scrollbars definitively dissapears after resizing the frame. Thx for help #-- import wx,wx.grid #-- class MainWindow(wx.Frame): def __init__(self,parent,id,title): wx.Frame.__init__(self,parent,wx.ID_ANY,title) #-- self.grid= wx.grid.Grid(id=wx.ID_ANY,parent=self) self.grid.CreateGrid(numRows=10,numCols=2) self.grid.Fit() self.Fit() #-- self.Show(1) #-- app = wx.PySimpleApp() frame=MainWindow(None,-1,'Grid sizer') app.MainLoop() del app If I understand this correctly, that is normal. Your grid is only two columns by 10 rows, so if you resize your frame so that it shows all rows and columns, the scroll bars will disappear, much like other apps, such as FireFox. If you enlarge the frame enough, the scrollbars go away. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: PMW widget - skip tabbing to it
On Mar 26, 11:27 am, [EMAIL PROTECTED] wrote:
On Mar 26, 11:17 am, [EMAIL PROTECTED] wrote:
On Mar 26, 10:51 am, jp [EMAIL PROTECTED] wrote:
I have multiple PMW widgets (EntryFields, ScrolledField etc), how can
I skip over these widgets when using the tab key?
Thank you,
John
I would probably write some custom event handling. Something that
could tell it was a key-press event and not just an on-focus event.
Then it would be a simple, if key-press == tab, put focus on next
# widget of interest. Something like that should work.
Mike
I looked in my Tkinter book, and it says that if the widget has the
takefocus option set to true, the widget is placed in the tab group
and will get focus when they are tabbed to. I assume that this means
if you set the PMW widgets' takefocus option to false, they will be
skipped over since they won't be in the tab group.
Mike
I've tried using the takefocus option set to 0 and 1 but either way,
the tab key still stops at my EntryField. Below is my snippet of
code. What am I doing wrong?
entry=Pmw.EntryField(frame,
labelpos = 'w',
value = ,
label_text =
'Name:')
entry.grid(row=1)
#entry.component('entry').takefocus = 1
entry.component('entry').takefocus = 0
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Re: functions, classes, bound, unbound?
On Mar 26, 7:15 pm, 7stud [EMAIL PROTECTED] wrote: On Mar 25, 3:09 pm, Steven Bethard [EMAIL PROTECTED] wrote: Here's another way of looking at it:: class Test(object): ... pass ... def greet(): ... print 'Hello' ... Test.greet = greet Test.greet unbound method Test.greet Interesting. After playing around with that example a bit and finally thinking I understood bound v. unbound, I found what appears to be an anomaly: class Test(object): pass def greet(x): print hello Test.func = greet print Test.func t = Test() print t.func def sayBye(x): print bye t.bye = sayBye print t.bye output: unbound method Test.greet bound method Test.greet of __main__.Test object at 0x6dc50 function sayBye at 0x624b0 Why doesn't t.bye cause a method object to be created? Because that would be bad and unexpected behaviour. I might want to store callback functions to an object as attributes. It wouldn't make sense for the functions to be bound to the container object when I'd access them. Of course, Test.func = greet; print Test.func is also unexpected behaviour as Test.func is not same as Test.__dict__['func']. But it's unexpected in a good way, because it facilitates the way classes are usually used. The whole point of the magic is to make common idioms simple. -- http://mail.python.org/mailman/listinfo/python-list
Re: functions, classes, bound, unbound?
On Mar 26, 5:08 am, Bruno Desthuilliers bruno. [EMAIL PROTECTED] wrote: Most of Python's object model is documented here: http://www.python.org/download/releases/2.2.3/descrintro/http://users.rcn.com/python/download/Descriptor.htm Thanks. I've looked at both of those, and the second one is very good. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On Mar 26, 9:42 am, Jean-Paul Calderone [EMAIL PROTECTED] wrote: On 26 Mar 2007 06:20:32 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: OK... I've been told that Both Fortran and Python are easy to read, and are Python is hugely easier to read. quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level Fortran is massively faster than Python. language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? You can get the speed of fortran in Python by using libraries like Numeric without losing the readability of Python. This is true only for problems that can take advantage of scalability, which is a large and important subset of all numerical problems, but is still only a subset. Some problems (e.g., simulation) require repeated sequential evaluation of formulas. For other problems (e.g., collision detection) the operands change rapidly. The scalability of numpy doesn't help so much here. (Anecdote: I once did a collision detection using Numeric. It would take slices out of the data set as it narrowed down the possible collisions. It actually worked pretty well. But the slicing was crazy and hard to follow. I rewrote it in C and it was both faster and more readable.) Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
[EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] OK... I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Thanks Chris So, after reading much of animated debate here, I think few would suggest that Python is going to be faster than FORTRAN when it comes to raw execution speed. Numeric and SciPy are Python modules that are geared towards numerical computing and can give substantial performance gians over plain Python. A reasonable approach (which has already been hinted at here), is to try to have the best of both world by mixing Python and FORTRAN - doing most of the logic and support code in Python and writing the raw computing routines in FORTRAN. A reasonable approach might be to simply make your application work in Python, then use profiling to identify what parts are slowest and move those parts into a complied language such as FORTRAN or C if overall performance is not fast enough. Unless your number crunching project is truly massive, you may find that Python is a lot faster than you thought and may be plenty fast enough on it's own. So, there is a tradeoff of resources between development time, execution time, readability, understandability, maintainability, etc. psyco is a module I haven't seen mentioned here - I don't know a lot about it, but have seen substantial increases in performance in what little I have used it. My understanding is that it produces multiple versions of functions tuned to particular data types, thus gaining some advantage over the default, untyped bytecode Python would normally produce. You can think of it as a JIT compiler for Python (but that's not quite what it is doing). The home page for that module is here: http://psyco.sourceforge.net/ Hope that help, -ej -- http://mail.python.org/mailman/listinfo/python-list
Re: Fortran vs Python - Newbie Question
On 26 Mar, 17:59, Erik Johnson [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] OK... I've been told that Both Fortran and Python are easy to read, and are quite useful in creating scientific apps for the number crunching, but then Python is a tad slower than Fortran because of its a high level language nature, so what are the advantages of using Python for creating number crunching apps over Fortran?? Thanks Chris So, after reading much of animated debate here, I think few would suggest that Python is going to be faster than FORTRAN when it comes to raw execution speed. Numeric and SciPy are Python modules that are geared towards numerical computing and can give substantial performance gians over plain Python. A reasonable approach (which has already been hinted at here), is to try to have the best of both world by mixing Python and FORTRAN - doing most of the logic and support code in Python and writing the raw computing routines in FORTRAN. A reasonable approach might be to simply make your application work in Python, then use profiling to identify what parts are slowest and move those parts into a complied language such as FORTRAN or C if overall performance is not fast enough. Unless your number crunching project is truly massive, you may find that Python is a lot faster than you thought and may be plenty fast enough on it's own. So, there is a tradeoff of resources between development time, execution time, readability, understandability, maintainability, etc. psyco is a module I haven't seen mentioned here - I don't know a lot about it, but have seen substantial increases in performance in what little I have used it. My understanding is that it produces multiple versions of functions tuned to particular data types, thus gaining some advantage over the default, untyped bytecode Python would normally produce. You can think of it as a JIT compiler for Python (but that's not quite what it is doing). The home page for that module is here: http://psyco.sourceforge.net/ Hope that help, -ej Ok Thanks you all for giving a little insight into what Python can actually do, I think I've read enough to convince me that Python is generally a very flexible, fast, powerful language that can be used in a wide variety of applications instead of focusing on numerical functions like fortran does. Thanks again! -- http://mail.python.org/mailman/listinfo/python-list
how to abort on syntax errors
I have a lot of except Exception, e statements in my code, which poses some problems. One of the biggest is whenever I refactor even the triviallest thing in my code. I would like python to abort, almost as if it were a compile-time error, whenever it cannot find a function, or if I introduced a syntax error. But, instead, it merrily proceeds on its way. Is there some idiom that you use in situations like these? thanks, josh -- http://mail.python.org/mailman/listinfo/python-list
fetch html page via isa proxy
Hi, I have been trying several days to get the html page of www.python.org when behind the corporate MS isa proxy. I have tried setting http_proxy environment, played with proxy openers, use ntlm proxy server all without success. I can get the page using Firefox and IE with proxy settings. As the last resort I started to play with pywin32 win32inet, but even the test_win32inet.py does not get there. Any advice? Or better working example? Thanks a lot, Radek -- http://mail.python.org/mailman/listinfo/python-list
Re: PMW widget - skip tabbing to it
On Mar 26, 11:35 am, jp [EMAIL PROTECTED] wrote:
On Mar 26, 11:27 am, [EMAIL PROTECTED] wrote: On Mar 26, 11:17 am, [EMAIL
PROTECTED] wrote:
On Mar 26, 10:51 am, jp [EMAIL PROTECTED] wrote:
I have multiple PMW widgets (EntryFields, ScrolledField etc), how can
I skip over these widgets when using the tab key?
Thank you,
John
I would probably write some custom event handling. Something that
could tell it was a key-press event and not just an on-focus event.
Then it would be a simple, if key-press == tab, put focus on next
# widget of interest. Something like that should work.
Mike
I looked in my Tkinter book, and it says that if the widget has the
takefocus option set to true, the widget is placed in the tab group
and will get focus when they are tabbed to. I assume that this means
if you set the PMW widgets' takefocus option to false, they will be
skipped over since they won't be in the tab group.
Mike
I've tried using the takefocus option set to 0 and 1 but either way,
the tab key still stops at my EntryField. Below is my snippet of
code. What am I doing wrong?
entry=Pmw.EntryField(frame,
labelpos = 'w',
value = ,
label_text =
'Name:')
entry.grid(row=1)
#entry.component('entry').takefocus = 1
entry.component('entry').takefocus = 0
According to the Tkinter book, setting takefocus to 0 (false) should
work. Are you putting th EntryField into a Grid? If so, that might be
the problem. I suppose the grid may override its children's settings.
I've never messed too much with skipping widgets in the tab order. You
could pack the PMW widgets last so that they won't get tabbed to until
the end.
There's also tk_focusNext tk_focusPrev. See the following post for
more info and ideas:
http://www.dbforums.com/archive/index.php/t-1377788.html
Mike
--
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Re: Python object overhead?
On Mar 26, 9:13 am, Matt Garman [EMAIL PROTECTED] wrote: On 3/23/07, Jack Diederich [EMAIL PROTECTED] wrote: If you make the record a new style class (inherit from object) you can specify the __slots__ attribute on the class. This eliminates the per instance dictionary overhead in exchange for less flexibility. When you say new style class, do you mean that the __slots__ feature is only available in a newer version of Python? Unfortunately, I'm stuck on 2.3.4 for this project. __slots__ were made available in 2.2 according to GvR's tutorial here: http://www.python.org/download/releases/2.2.3/descrintro/ -- http://mail.python.org/mailman/listinfo/python-list
Re: how to abort on syntax errors
On Mar 26, 12:21 pm, Josh [EMAIL PROTECTED] wrote: I have a lot of except Exception, e statements in my code, which poses some problems. One of the biggest is whenever I refactor even the triviallest thing in my code. I would like python to abort, almost as if it were a compile-time error, whenever it cannot find a function, or if I introduced a syntax error. But, instead, it merrily proceeds on its way. Is there some idiom that you use in situations like these? thanks, josh Try sticking in an try: #do something except SyntaxError, e: print e sys.exit(0) except Exception, e: print e # You put in as many exceptions as you like. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: how to abort on syntax errors
Josh I have a lot of except Exception, e statements in my code, which Josh poses some problems. One of the biggest is whenever I refactor Josh even the triviallest thing in my code. Josh I would like python to abort, almost as if it were a compile-time Josh error, whenever it cannot find a function, or if I introduced a Josh syntax error. But, instead, it merrily proceeds on its way. Josh Is there some idiom that you use in situations like these? In general, I think you should be more specific in the exceptions you catch. For example, if you want to look up a key in a dictionary and most of the time it's there, but every now and again you need to add it, I'd use something like this: try: val = somedict[key] except KeyError: # need to initialize slot somedict[key] = INITIAL_VALUE That is, be as precise as you can in the exceptions you catch. Also, try to keep the body of the try block as small as you can. Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: how to abort on syntax errors
In [EMAIL PROTECTED], Josh wrote: I have a lot of except Exception, e statements in my code, which poses some problems. One of the biggest is whenever I refactor even the triviallest thing in my code. I would like python to abort, almost as if it were a compile-time error, whenever it cannot find a function, or if I introduced a syntax error. But, instead, it merrily proceeds on its way. Is there some idiom that you use in situations like these? Just don't use so many ``except Exception:`` constructs that obviously swallow exceptions they shouldn't swallow. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: how to abort on syntax errors
[EMAIL PROTECTED] wrote: On Mar 26, 12:21 pm, Josh [EMAIL PROTECTED] wrote: I have a lot of except Exception, e statements in my code, which poses some problems. One of the biggest is whenever I refactor even the triviallest thing in my code. I would like python to abort, almost as if it were a compile-time error, whenever it cannot find a function, or if I introduced a syntax error. But, instead, it merrily proceeds on its way. Is there some idiom that you use in situations like these? thanks, josh Try sticking in an try: #do something except SyntaxError, e: print e sys.exit(0) except Exception, e: print e # You put in as many exceptions as you like. Of course the main problem with this solution is that a piece of code will raise a syntax error when it's compiled (i.e. at module import time, or when the main program starts up). So in the case where #do something has a syntax error it won;t be trapped because the program hasn't got to execution by the time the error is detected. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden Recent Ramblings http://holdenweb.blogspot.com -- http://mail.python.org/mailman/listinfo/python-list
