🌐 Mailman 3 July 2003 - Python-list - python.org

Re: Howto: extract a 'column' from a list of lists into a new list?
by Lulu of the Lotus-Eaters July 1, 2003

July 1, 2003

"Greg Brunet" <gregbrunet(a)NOSPAMsempersoft.com> wrote previously: |>>> tbl.Fields() |[('STOCKNO', 'C', 8, 0), ('DACC', 'C', 5, 0), ('DEALERACCE', 'C', 30, |0), ('D-ACCRTL', 'C', 9, 0), ('D-ACCCST', 'C', 9, 0)] NAME,TYPE,LEN,DEC = range(4) names = [row[NAME] for row in tbl.Fields()] -- Keeping medicines from the bloodstreams of the sick; food from the bellies of the hungry; books from the hands of the uneducated; technology from the underdeveloped; and putting advocates of freedom in prisons. Intellectual property is to the 21st century what the slave trade was to the 16th.

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Python 2.0 / Python 2.2
by Gina Schuffenhauer July 1, 2003

July 1, 2003

Hallo newsgroup, I have some questions concerning Python 2.2. First question: I try to port source code from Python 2.0 to Python 2.2.The following source code works with Python 2.0. If I compile it with Python 2.2, the modul "tci" is not imported. "tci" is a python module written by us. How can I change the source code to get it working with Python 2.2.? Py_Initialize(); PyStr = Py_BuildValue("s", TCIHome); PyModule = PyImport_ImportModule("sys"); PyList = PyObject_GetAttrString(PyModule, "path"); PyList_Insert(PyList, 0, PyStr); if (PyErr_Occurred()) return 0; TCIModule = PyImport_ImportModule("tci"); Second question: I want to embed Pythonwin in a C++-Application. Where can I find a win32uiHostGlue.h to access win32ui.pyd version 2.1.0.152? -- Mit freundlichen Grüßen / best regards Gina Schuffenhauer schuffenhauer(a)IWQ.de

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I need a lot of help!
by Jewlz408＠aol.com July 1, 2003

July 1, 2003

I need a lot of help What do you know about Arrays How many storage Locations will be allocated for each of the given arrays? 1) Dim A(1 to 10) 2) Dim B(-3 to 5) 3) Dim C$( 12) 4) Dim D( 1 to 4, -2 to 2) 5) Dim E(4,6) And What does the following programs do with its output? Dim Table( 1 to 5, 1 to 3) For I = 1 to 5 For J = 1 to 3 Let Table(I,J) = 1 Next J Next I End What does the program do? And what is the output? Thankyou so much for your time Please help me!

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problem w/ numarray & py2exe...
by RJS July 1, 2003

July 1, 2003

Hi all, I can't get a py2exe compiled app to run with numarray (numarray-0.5.win32- py2.2). Also wxPythonWIN32-2.3.3.1-Py22 and ActivePython-2.2.1-222. In the sample below, commenting out "import numarray" allows the exe to run. Left in, I get "4.exe has generated errors" etc. I'm going around and around and there isn't much on Google. py2exe output is last. With "Python 4.py" from the shell, all is well. Any ideas? Older numarray? Numeric? Ray http://rjs.org ############################### setup.py ############# from distutils.core import setup import py2exe setup(name="tf.4", scripts=["4.py"], ) ############################# 4.py code ################ from wxPython.wx import * import numarray import array import operator from random import Random ID_STUB = 10 ID_IMPORT_XRC = 100 ID_PLOT = 111 ID_TRAIN = 122 ID_EXPORT_ONEREV= 124 ID_EXIT = 199 ID_ABOUT = 141 ############################# Class defs ############################# class MainFrame(wxFrame): def __init__(self, parent, ID, title): wxFrame.__init__(self, parent, ID, title, wxDefaultPosition, wxSize(800, 400)) if wxPlatform == '__WXMSW__': self.icon = wxIcon('imagery/rotor.ico', wxBITMAP_TYPE_ICO) self.SetIcon(self.icon) self.Centre(direction = wxBOTH) self.CreateStatusBar() self.SetStatusText("Status: ready") ## create the menubar fileMenu = wxMenu() fileMenu.Append(ID_IMPORT_XRC, "Import &*.xrc", "Import an xrc data file") fileMenu.AppendSeparator() fileMenu.Append(ID_EXPORT_ONEREV, "&Export", "Export One Rev data") fileMenu.AppendSeparator() fileMenu.Append(ID_EXIT, "E&xit", "Terminate the program") toolsMenu = wxMenu() toolsMenu.Append(ID_STUB, "Color", "Change the color scheme") toolsMenu.AppendSeparator() toolsMenu.Append(ID_PLOT, "Plot", "Plot the data") toolsMenu.Append(ID_TRAIN, "Train", "Train on the data") helpMenu = wxMenu() helpMenu.Append(ID_STUB, "&Help", "Index and glossary") helpMenu.AppendSeparator() helpMenu.Append(ID_ABOUT, "&About", "More information about this program") menuBar = wxMenuBar() menuBar.Append(fileMenu, "&File"); menuBar.Append(toolsMenu, "&Tools"); menuBar.Append(helpMenu, "&Help"); self.SetMenuBar(menuBar) EVT_MENU(self, ID_IMPORT_XRC, self.OnImportXRC) EVT_MENU(self, ID_PLOT, self.createPlot) EVT_MENU(self, ID_TRAIN, self.OnTraining) EVT_MENU(self, ID_EXPORT_ONEREV, self.OnExport) EVT_MENU(self, ID_ABOUT, self.OnAbout) EVT_MENU(self, ID_EXIT, self.ExitFrame) ##### create and add notebook pages #################################################################### self.nb = wxNotebook(self, -1) self.fontObj = wxFont(11, wxMODERN, wxNORMAL, wxNORMAL, false) def OnAbout(self, event): dlg = wxMessageDialog(self, "Welcome to\n" "Turbine v.1\n", "Welcome", wxOK | wxICON_INFORMATION) dlg.ShowModal() dlg.Destroy() self.nb.DeletePage(0) def ExitFrame(self, event): self.Close(true) # ---------------------------------------------------------------------- ------------------ # handlers. # ---------------------------------------------------------------------- ------------------ def OnImportXRC(self, event): self.dataPoints = 5000 # open the header file dlg = wxFileDialog (self, "Select the XRC file for import", "data", "", "*.xrc", wxOPEN) if dlg.ShowModal() == wxID_OK: try: self.filePath = dlg.GetPath() except IOError: dlg_m = wxMessageDialog (self, 'There was an error opening the new xrc file.', 'Error!', wxOK) dlg_m.ShowModal() dlg_m.Destroy() dlg.Destroy() def createDataArray(self): # create the XRC tabs self.nb.xrcHeader = wxTextCtrl(self.nb, -1, "",wxPoint(0, 0), wxSize(75, 20), wxTE_MULTILINE|wxTE_RICH ) self.nb.xrcHeader.SetStyle(0, self.nb.xrcHeader.GetLastPosition(), wxTextAttr("BLACK", wxNullColour, self.fontObj)) self.nb.AddPage(self.nb.xrcHeader, "XRC Header: "+self.filePath) self.nb.xrcHeader.LoadFile(self.filePath) def createPlot(self, event=NULL): plotWidthPoints = 5000 def OnExport(self, event): self.nb.SetSelection(1) def OnTraining(self, event=NULL): firstSet = TRUE def createOneRevPlot(self, pointsPerRev, revs): plotWidthPoints = int(pointsPerRev) self.nb.AdvanceSelection() def OnExport(self, event): self.nb.SetSelection(3) def histogram(self,a, bins): return 1 ############### Main application class ########### class App(wxApp): def OnInit(self): frame = MainFrame(NULL, -1, "Turbine ") frame.Show(true) self.SetTopWindow(frame) return true app = App(0) app.MainLoop() ################# py2exe output ##################### D:\projects\fingerprinting>python setup.py py2exe running py2exe running build running build_scripts not copying 4.py (up-to-date) running install_scripts creating build\bdist.win32\winexe creating build\bdist.win32\winexe\lib creating build\bdist.win32\winexe\lib\Python creating build\bdist.win32\winexe\lib\Python\Scripts copying build\scripts-2.2\4.py -> build\bdist.win32\winexe\lib\Python\Scripts copying build\scripts-2.2\tf.4.py -> build\bdist.win32\winexe\lib\Python\Scripts copying build\scripts-2.2\tf.5.py -> build\bdist.win32\winexe\lib\Python\Scripts +---------------------------------------------------- | Processing script 4.py with py2exe-0.3.4 +---------------------------------------------------- creating build\bdist.win32\winexe\collect creating build\bdist.win32\winexe\collect\4 creating build\bdist.win32\winexe\collect\4\Scripts.py2exe Searching modules needed to run '4.py' on path: ['D:\\projects\\fingerprinting\\build\\bdist.win32\\winexe\\lib\\Python\\Li b\\si te-packages', '', 'D:\\Python\\Lib\\site-packages\\Pythonwin', 'D:\\Python\\Lib\ \site-packages\\win32', 'D:\\Python\\Lib\\site-packages\\win32\\lib', 'D:\\Pytho n\\Lib\\site-packages', 'D:\\Python\\DLLs', 'D:\\Python\\lib', 'D:\\Python\\lib\ \lib-tk', 'D:\\Python', 'D:\\Python\\lib\\site-packages\\numarray'] force_imports = Resolving binary dependencies: D:\Python\lib\site-packages\numarray\_numarray.pyd D:\Python\lib\site-packages\numarray\_operator.pyd D:\Python\Lib\site-packages\py2exe\run.exe D:\Python\Lib\site-packages\wxPython\utilsc.pyd D:\Python\lib\site-packages\numarray\_conv.pyd D:\Python\lib\site-packages\numarray\_bytes.pyd D:\Python\lib\site-packages\numarray\_ufunc.pyd D:\Python\lib\site-packages\numarray\_converter.pyd D:\Python\Lib\site-packages\wxPython\wxmsw233h.dll D:\Python\Lib\site-packages\wxPython\wxc.pyd C:\WIN2000\System32\python22.dll D:\Python\lib\site-packages\numarray\_ndarray.pyd D:\Python\lib\site-packages\numarray\memory.pyd D:\Python\lib\site-packages\numarray\_sort.pyd D:\Python\Lib\site-packages\wxPython\wxmsw232h.dll D:\Python\DLLs\_sre.pyd ext_mapping = { '_conv': ('_conv.pyd', ('.pyd', 'rb', 3)) '_ndarray': ('_ndarray.pyd', ('.pyd', 'rb', 3)) '_sort': ('_sort.pyd', ('.pyd', 'rb', 3)) '_converter': ('_converter.pyd', ('.pyd', 'rb', 3)) '_numarray': ('_numarray.pyd', ('.pyd', 'rb', 3)) '_ufunc': ('_ufunc.pyd', ('.pyd', 'rb', 3)) '_operator': ('_operator.pyd', ('.pyd', 'rb', 3)) '_bytes': ('_bytes.pyd', ('.pyd', 'rb', 3)) 'memory': ('memory.pyd', ('.pyd', 'rb', 3)) 'wxPython.utilsc': ('utilsc.pyd', ('.pyd', 'rb', 3)) '_sre': ('_sre.pyd', ('.pyd', 'rb', 3)) 'wxPython.wxc': ('wxc.pyd', ('.pyd', 'rb', 3)) } copying D:\Python\Lib\site-packages\py2exe\support.py -> build\bdist.win32\winex e\collect\4\Scripts.py2exe byte-compiling D:\Python\lib\pre.py to pre.pyc byte-compiling D:\Python\lib\__future__.py to __future__.pyc byte-compiling D:\Python\lib\copy_reg.py to copy_reg.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\fonts.py to wxPython\fonts.p yc byte-compiling D:\Python\Lib\site-packages\wxPython\windows.py to wxPython\windo ws.pyc byte-compiling D:\Python\lib\locale.py to locale.pyc byte-compiling D:\Python\lib\random.py to random.pyc byte-compiling D:\Python\lib\popen2.py to popen2.pyc byte-compiling D:\Python\lib\stat.py to stat.pyc byte-compiling D:\Python\lib\imputil.py to imputil.pyc byte-compiling D:\Python\lib\site-packages\numarray\_ufuncall.py to _ufuncall.py c byte-compiling D:\Python\Lib\site-packages\wxPython\events.py to wxPython\events .pyc byte-compiling D:\Python\Lib\site-packages\wxPython\utils.py to wxPython\utils.p yc byte-compiling D:\Python\lib\site-packages\numarray\arrayprint.py to arrayprint. pyc byte-compiling D:\Python\lib\string.py to string.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\printfw.py to wxPython\print fw.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\misc.py to wxPython\misc.pyc byte-compiling D:\Python\lib\re.py to re.pyc byte-compiling D:\Python\lib\tempfile.py to tempfile.pyc byte-compiling D:\Python\lib\warnings.py to warnings.pyc byte-compiling D:\Python\lib\site-packages\numarray\typeconv.py to typeconv.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\streams.py to wxPython\strea ms.pyc byte-compiling D:\Python\lib\sre_constants.py to sre_constants.pyc byte-compiling D:\Python\lib\ntpath.py to ntpath.pyc byte-compiling D:\Python\lib\sre_compile.py to sre_compile.pyc byte-compiling D:\Python\lib\getopt.py to getopt.pyc byte-compiling D:\Python\lib\site-packages\numarray\ufunc.py to ufunc.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\controls2.py to wxPython\con trols2.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\windows3.py to wxPython\wind ows3.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\stattool.py to wxPython\stat tool.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\controls.py to wxPython\cont rols.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\__version__.py to wxPython\_ _version__.pyc byte-compiling D:\Python\lib\UserDict.py to UserDict.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\wx.py to wxPython\wx.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\sizers.py to wxPython\sizers .pyc byte-compiling D:\Python\lib\repr.py to repr.pyc byte-compiling D:\Python\lib\sre_parse.py to sre_parse.pyc byte-compiling D:\Python\lib\copy.py to copy.pyc byte-compiling D:\Python\lib\site-packages\numarray\numerictypes.py to numericty pes.pyc byte-compiling D:\Python\lib\types.py to types.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\filesys.py to wxPython\files ys.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\windows2.py to wxPython\wind ows2.pyc byte-compiling D:\Python\lib\dospath.py to dospath.pyc byte-compiling D:\Python\lib\sre.py to sre.pyc byte-compiling D:\Python\lib\site-packages\numarray\numarray.py to numarray.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\misc2.py to wxPython\misc2.p yc byte-compiling D:\Python\lib\site-packages\numarray\ndarray.py to ndarray.pyc byte-compiling D:\Python\lib\linecache.py to linecache.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\frames.py to wxPython\frames .pyc byte-compiling D:\Python\Lib\site-packages\wxPython\__init__.py to wxPython\__in it__.pyc byte-compiling D:\Python\lib\posixpath.py to posixpath.pyc byte-compiling D:\Python\lib\site-packages\numarray\numinclude.py to numinclude. pyc byte-compiling D:\Python\Lib\site-packages\wxPython\cmndlgs.py to wxPython\cmndl gs.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\image.py to wxPython\image.p yc byte-compiling D:\Python\Lib\site-packages\wxPython\mdi.py to wxPython\mdi.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\gdi.py to wxPython\gdi.pyc byte-compiling D:\Python\lib\os.py to os.pyc byte-compiling D:\Python\Lib\site-packages\wxPython\clip_dnd.py to wxPython\clip _dnd.pyc copying 4.py -> build\bdist.win32\winexe\collect\4\Scripts.py2exe\__main__.py changing into 'build\bdist.win32\winexe\collect\4' zip -rq D:\projects\fingerprinting\build\bdist.win32\winexe\4.zip . creating 'D:\projects\fingerprinting\build\bdist.win32\winexe\4.zip' and adding '.' to it changing back to 'D:\projects\fingerprinting' creating dist\4\4.exe warning: py2exe: could not parse version number '' No VersionInfo will be created not copying D:\Python\lib\site-packages\numarray\_numarray.pyd (output up- to-dat e) not copying D:\Python\lib\site-packages\numarray\_operator.pyd (output up- to-dat e) not copying D:\Python\Lib\site-packages\wxPython\utilsc.pyd (output up-to- date) not copying D:\Python\lib\site-packages\numarray\_conv.pyd (output up-to- date) not copying D:\Python\lib\site-packages\numarray\_bytes.pyd (output up-to- date) not copying D:\Python\lib\site-packages\numarray\_ufunc.pyd (output up-to- date) not copying D:\Python\lib\site-packages\numarray\_converter.pyd (output up- to-da te) not copying D:\Python\Lib\site-packages\wxPython\wxmsw233h.dll (output up- to-dat e) not copying D:\Python\Lib\site-packages\wxPython\wxc.pyd (output up-to- date) not copying C:\WIN2000\System32\python22.dll (output up-to-date) not copying D:\Python\lib\site-packages\numarray\_ndarray.pyd (output up- to-date ) not copying D:\Python\lib\site-packages\numarray\memory.pyd (output up-to- date) not copying D:\Python\lib\site-packages\numarray\_sort.pyd (output up-to- date) not copying D:\Python\Lib\site-packages\wxPython\wxmsw232h.dll (output up- to-dat e) not copying D:\Python\DLLs\_sre.pyd (output up-to-date) warning: py2exe: *************************************************************** ********** warning: py2exe: * The following modules were not found: warning: py2exe: * cmndlgsc warning: py2exe: * imagec warning: py2exe: * clip_dndc warning: py2exe: * windows3c warning: py2exe: * filesysc warning: py2exe: * eventsc warning: py2exe: * windows2c warning: py2exe: * controlsc warning: py2exe: * misc2c warning: py2exe: * os.path warning: py2exe: * windowsc warning: py2exe: * stattoolc warning: py2exe: * printfwc warning: py2exe: * gdic warning: py2exe: * sizersc warning: py2exe: * mdic warning: py2exe: * fontsc warning: py2exe: * streamsc warning: py2exe: * miscc warning: py2exe: * controls2c warning: py2exe: * framesc warning: py2exe: *************************************************************** ********** removing 'build\bdist.win32\winexe\collect\4' (and everything under it) Built File dist\4\4.exe removing 'build\bdist.win32\winexe' (and everything under it)

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error message in Python...
by erez＠actona.com July 1, 2003

July 1, 2003

Hi, When i try to run python script that uses com object from dll (was registered already) i got the next error message the script already was run on some other computer (win2k, xp) but in this specific device it refused. The Message: dispatch, userName = dynamic._GetGoodDispatchAndUserName(dispatch,userName,clsctx) File "C:\Python22\Lib\site-packages\win32com\client\dynamic.py", line 81, in _GetGoodDispatchAndUserName return (_GetGoodDispatch(IDispatch, clsctx), userName) File "C:\Python22\Lib\site-packages\win32com\client\dynamic.py", line 72, in _GetGoodDispatch IDispatch = pythoncom.CoCreateInstance(IDispatch, None, clsctx, pythoncom.IID_IDispatch) pywintypes.com_error: (-2147024770, 'The specified module could not be found.', None, None) Does any one know what it's mean ???

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Re: Exposing object model in Python?
by jwhitlark＠attbi.com July 1, 2003

July 1, 2003

"Fredrik Lundh" <fredrik(a)pythonware.com> wrote in message news:<mailman.1056722085.11922.python-list(a)python.org>... > macrosource = getmacro(macroname) > code = compile(macrosource, macroname, "exec") > context = {} > # populate context with fun things > context["app"] = object_representing_my_app > exec code in context > > (add exception handling as necessary) > > </F> Excellent, I was interested in that too. Ok, here's something similar I've struggled with... How do you provide a macro recorder? I have some idea how to just play back a sequence of actions, (just store signals in a list, then fire them in order), but how do you turn that back into python code, like in Word VB?

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Re: How to catch 'error' type exceptions
by bokr＠oz.net July 1, 2003

July 1, 2003

On 30 Jun 2003 13:22:32 -0700, kevin(a)cazabon.com (Kevin Cazabon) wrote: >Your problem is that "error" is not a valid exception type in Python. >You "should" be trying to catch a specific problem so that you can >handle it appropriately (such as socket.error as mentioned by another >poster). > >The lazy, dangerous way would be: > >try: > # some error-generating code >except Exception, reason: > print reason > >but that's not recommended good coding practice. > Yes, certainly not internally, unless re-raising all or selected exceptions, but as an outside wrapper to a whole app, why not? (You could make traceback printing depend on __debug__ or some other option if desired). You could also detect and eliminate redundant repetition in a traceback print of a recursion limit exception. (I think that would be a nice default, BTW). Regards, Bengt Richter

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Re: Howto: extract a 'column' from a list of lists into a new list?
by Greg Brunet July 1, 2003

July 1, 2003

"Egor Bolonev" <ebolonev(a)rol.ru> wrote in message news:bdqp9e$7r$1@news.rol.ru... > ============================================= > a=[('STOCKNO', 'C', 8, 0), ('DACC', 'C', 5, 0), ('DEALERACCE', 'C', 30, > 0), ('D-ACCRTL', 'C', 9, 0), ('D-ACCCST', 'C', 9, 0)] > > b=[x[0] for x in a] # :-) Python is cool! > > print b > ============================================= > > As I know the map/lamda/list works very slow and you should use it 'only' > with SCRIPTS. Thanks Egor! It looks like I was closer than I thought - but still would have been unlikely to figure it out! -- Greg

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Bitte bestaetigen | Please confirm your message
by sven＠ping.de July 1, 2003

July 1, 2003

Ihre e-mail mit dem Betreff | Your e-mail message with the subject of "Re: Application" wird zurueckgehalten, da die | is being held because your address was Absenderadresse nicht bekannt ist. | not recognized. Um die Zustellung der Nachricht zu | veranlassen, senden Sie bitte eine | To release your message for delivery, leere Nachricht an die folgende | please send an empty message Adresse, oder benutzen Sie die | to the following address, or use "Antworten" Funktion Ihrer Software | your mailer's "Reply" feature. sven-confirm-accept.1057023328.5431.64b685(a)ping.de Die einmalige Bestaetigung dient | This onetime confirmation verifies that dazu, Ihre Mail zu legitimieren und | your message is legitimate and not unerwuenschten Spam abzufangen. | junk-mail. [ This notice was generated by TMDA (http://tmda.sf.net/), an automated junk-mail reduction system. ] --- Enclosed is a copy of your message. Received: (qmail 5429 invoked by alias); 1 Jul 2003 01:35:27 -0000 Delivered-To: fuzzy.ping.de-sven(a)fuzzy.ping.de Received: (qmail 5403 invoked from network); 1 Jul 2003 01:35:17 -0000 Received: from unknown (HELO BREAKROOM5) (208.62.166.215) by ping-gw.aironet1.knipp.de with SMTP; 1 Jul 2003 01:35:17 -0000 From: <python-list(a)python.org> To: <sven(a)fuzzy.ping.de> Subject: Re: Application Date: Mon, 30 Jun 2003 21:35:17 --0400 Importance: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MSMail-Priority: Normal X-Priority: 3 (Normal) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="CSmtpMsgPart123X456_000_06FC8BFD" [ Message body suppressed (exceeded 50000 bytes) ]

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Re: Newbie: "compiling" scrips (?)
by Alan Kennedy July 1, 2003

July 1, 2003

Gerrit Holl wrote: > I don't understand how pypy can improve performance. Am I correct that pypy > is an effort to implement Python as much as possible in Python? Yes, that's a part of what the PyPy people are doing. > And am I > correct that implementing a module in C will probably speed it up? In some scenarios, implementing a module in C will speed things up, but it is not guaranteed. It depends on the data being transferred back and forth between the C extension and the users python script. This transfer comes at a cost. If the cost of the transfer outweighs the time spent in the C extension, then it will be slower. Which doesn't happen very often, mind. > Combining > these two, wouldn't implementing Python in Python slow things down? Not necessarily. That's true only if you assume that the python virtual machine interpreting the python byte codes doesn't run any faster than the current Python VM. > If so, > what is the advantage of pypy? >From my readings, I think the PyPy project is very ambitious (and I wish them the very best of luck getting funding for it). Since the current python implementation has gone through many evolutions, it has become tough to manage (at a code level) in certain areas. This is in no small part due to the number of platforms and C compilers that the current python works with, and the number of utilities used in producing the compiler, for lexing, parsing, etc. Because there is so much "inertia" in the codebase, a lot of time and effort go into making small changes. Reimplementing python, from the grammar up, in python would free up much development resources, allowing the python developers to focus more on things that are important, e.g. improving the language, and adding new libraries, etc. Also, PyPy can "leverage" (I hate that word) the fantastic portability of the current python implementation to be running everywhere quickly: i.e. the current Python VM would be the "bootstrap" VM. Also, a clean redesign of the compiler and interpreter would allow for hooks to be inserted for such products as psyco, which change the operation of the main interpreter loop (usually optimising it for speed efficiency). This is comparable to JIT in the jython world. Your jython script *may* run faster on one Java VM compared to another, because the JVM interpreting the jvm bytecodes may be using fancy assembler-level tricks to optimise for speed/memory/etc, e.g. the "hotspot" VM. You get the benefit of increased execution speed, without a single code change. Another advantage is that because your VM is simpler to understand, because it's written in python, it is easier to maintain and optimise. There is a data structure called an "Abstract Syntax Tree", which contains a representation of python your scripts as they are running. Sometimes, by recording statistics and doing pattern matching on the bytecodes that are running through the machine, it is possible to reduce the number of operations needed to execute a given script: this is called optimisation. Native code compilers do it all the time, but obviously only once at compilation time. Interpreters can optimise in exactly same way, but at run time. The above mentioned hotspot java VM is an instance of one of these. There are many pieces to what the PyPy people are trying to do, and they have a lot of work to do building the separate pieces, with nothing to show until it's all ready to fit nicely together. But I think their overall model looks promising. So hopefully, with the description above, you'll be in a better position to understand the content of these links. http://codespeak.net/moin/pypy/moin.cgi/PyPythonCore http://codespeak.net/moin/pypy/moin.cgi/ObjectModel http://codespeak.net/moin/pypy/moin.cgi/BytecodeCompiler http://codespeak.net/moin/pypy/moin.cgi/BytecodeInterpreter For a look at the kinds of tricks that optimising interpreters can use, in the java world, take a look over this link http://java.sun.com/products/hotspot/docs/whitepaper/Java_Hotspot_v1.4.1/Ja… Looking at the PyPy object model, I can't help but wonder how they're going to deal with continuations? (If full integration of stackless is the intention). -- alan kennedy ----------------------------------------------------- check http headers here: http://xhaus.com/headers email alan: http://xhaus.com/mailto/alan

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