🌐 Mailman 3 August 2008 - Tutor - python.org

Wave module
by Alex Krycek Feb. 12, 2015

Feb. 12, 2015

Hello, I'm trying to join two .wav files with the wave module. But when I try to use wave.open(filename, "rb") I receive the following error: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "F:\PortablePython1.0\lib\wave.py", line 483, in open return Wave_read(f) File "F:\PortablePython1.0\lib\wave.py", line 162, in __init__ self.initfp(f) File "F:\PortablePython1.0\lib\wave.py", line 143, in initfp self._read_fmt_chunk(chunk) File "F:\PortablePython1.0\lib\wave.py", line 264, in _read_fmt_chunk raise Error, 'unknown format: %r' % (wFormatTag,) wave.Error: unknown format: 85 I read somewhere that there are various wave formats, only some supported by Python. Is this true? If so, is there any way I can convert my wave files into a supported kind? Thanks!

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Send binary/hex data to a TCP socket
by Tod Haren July 19, 2011

July 19, 2011

I need to send a server at the other end of a socket a 36 byte "frame", where each byte represents a specific field in the custom data structure. (If there are any Ham operators reading this, I'm talking about the AGW Packet Engine) The documentation for the server says to initialize each field to a binary zero(0x00). How do I get a binary zero in Python? The next step is to send this all to the server and subsequently receive a similarly formated frame. A very basic frame looks something like this(modified from documentation): |00 00 00 00 4D 00 00 00 00 00 00 00 00 00 00 00 |....M........... |00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................ |00 00 00 00 |.... My problem is that hex(0) return '0x0' and hex(ord('M')) returns '0x4d'. If I concatonate these all together then the socket receives 109 bytes instead of 36. The documentation examples are in C++, so they are little help to me. The examples make use of the MoveMemory function for building the frames, but I'm clueless what that does. Pseudo code for the frame above: l = [] for i in xrange(36): l.append(hex(0)) l[4]=hex(ord('M')) d='' d=d.join(l) #I need some other data type to send besides a string! sock.send(d) #send the 36 bytes to the socket Any pointers or references would be greatly appreciated.

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cx_Oracle help
by Greg Lindstrom Jan. 6, 2011

Jan. 6, 2011

Hello, I'm trying to help out a friend and am stumped. Can you help me out? Thanks, --greg - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - I will briefly explain the problem I am facing. I am using Oracle 9.2, Python 2.5 and I installed cx_Oracle- 4.3.1-win32-9i-py25 in Python. From python I tried following : >>> import cx_Oracle >>> myDsn = cx_Oracle.makedsn('ISCN47',1521,'AUBDBS01') >>> CONN = cx_Oracle.connect(myusr, mypwd, myDsn) Traceback (most recent call last): File "<pyshell#4>", line 1, in <module> conn = cx_Oracle.Connection('scott','tiger',myDsn) RuntimeError: Unable to acquire Oracle environment handle I have set the below environment variables too NLS_LANG: <snip>.WE8MSWIN1252 ORACLE_HOME: D:\Tools\oracle\ora92 ORACLE_SID: AUBDBS01 PYTHON_HOME: d:\Utility\Python25 PYTHONPATH: %PYTHON_HOME%\lib;%PYTHON_HOME%\DLLs;%PYTHON_HOME%\Lib\site-packages;%ORACLE_HOME%\bin LD_LIBRARY_PATH: %LD_LIBRARY_PATH%;D:\Tools\oracle\ora92\lib Not getting any idea where I am wrong? Regards, Kishore

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Tracking time
by Michael Key Jan. 6, 2010

Jan. 6, 2010

I am trying to develop a project tracking program that would allow you to track hours and minutes spent on several different projects and store he data in a database for printing. Any help would be appreciated. Mike

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Learning Python
by Fred P Dec. 13, 2009

Dec. 13, 2009

Hey Everyone, I am completely new at python, but not new to programming or scripting. I have a couple of years of LUA scripting experience, about a year of C++ classes, and used to be very efficient at c-shell scripting in unix. My question for you guys: 1) How do I get Started? 2) Recommend any specific Books? 3) Any online tutors/ forums that would benefit a newbie 4) Any online classes that teach python? I have taken online c++ courses, and found them helpful. I was hoping to find something for python. My main objective is to write scripts for the following type of applications File management, file copies/syncs/ compares Text manipulation - like parsing text files to replace or augment specific values Integration into current applications to write redundant routines and maybe some day plugins I am not even sure what else, but I do know that every time i think of something that we need at work, other people say, "That would be a good task for a python script" and I would eventually like to be able to do something about that. Thanks Fred

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Re: [Tutor] Hands-on beginner's project?
by George Oliver Oct. 3, 2008

Oct. 3, 2008

> Python Universe Builder (PUB) is an Interactive Fiction module for > Python. It provides a > programming environment similar to that of Inform or TADS but runs > under any Python > interpreter. > > http://py-universe.sourceforge.net/ There also is PAWS (Python adventure writing system): http://home.fuse.net/wolfonenet/PAWS.htm Just for reference, other slightly more complicated examples of separating the game logic and data can be found in the mud genre. I recently wrote up a list of all the Python mud frameworks I could find: http://www.mudconnect.com/discuss/discuss.cgi?mode=MSG&area=coders&message=…

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How to create array of variants?
by Kelie Sept. 12, 2008

Sept. 12, 2008

Hello group, I'm trying to translate the following VB code into Python and not sure how to create an array of variants. Thanks for your help! VB Code: Sub SetXdata() Dim lineObj As AcadLine Set lineObj = ThisDrawing.ModelSpace.Item(0) Dim DataType(0 To 1) As Integer Dim Data(0 To 1) As Variant DataType(0) = 1001: Data(0) = "Test_Application" DataType(1) = 1070: Data(1) = 600 lineObj.SetXdata DataType, Data End Sub Python code import array import comtypes.client def SetXData(): activedoc = comtypes.client.GetActiveObject("AutoCAD.Application").ActiveDocument line = activedoc.ModelSpace.Item(0) dataType = array.array('i', [1001, 1070]) dataValue = array.array('?', ['Test_Application', 600]) #What should I use for the type code? line.SetXData(dataType, dataValue) if __name__ == "__main__": SetXData()

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Is this a "Class" problem?
by Adrian Greyling Sept. 2, 2008

Sept. 2, 2008

Hi folks! I hope I'm in the right place to ask this question. I'm new to Python and have been working through some tutorials and have made it to the GUI creation stage. All I was hoping to do with the code below, was to open a "secondary" window and have some text end up on a text_ctrl, but I get an error message that looks like this: Traceback (most recent call last): File "textbox2TEST.py", line 36, in MainToSecond MySecondFrame.text_ctrl_2.SetValue("This text was generated from the 'MainFrame' window") AttributeError: type object 'MySecondFrame' has no attribute 'text_ctrl_2' I'm using wxGlade and SPE together, so almost all of the code is generated for me. I just don't get why it doesn't work, although I think it has to do with one class referencing another class, and I'm obviously not doing that correctly... Any help is much appreciated! Here's the code that created the error: import wx class MyMainFrame(wx.Frame): def __init__(self, *args, **kwds): # begin wxGlade: MyMainFrame.__init__ kwds["style"] = wx.DEFAULT_FRAME_STYLE wx.Frame.__init__(self, *args, **kwds) self.text_ctrl_1 = wx.TextCtrl(self, -1, "", style=wx.TE_MULTILINE) self.button_1 = wx.Button(self, -1, "Click me to bring up second window and write some text") self.__set_properties() self.__do_layout() self.Bind(wx.EVT_BUTTON, self.MainToSecond, self.button_1) # end wxGlade def __set_properties(self): # begin wxGlade: MyMainFrame.__set_properties self.SetTitle("Main Frame") # end wxGlade def __do_layout(self): # begin wxGlade: MyMainFrame.__do_layout sizer_1 = wx.BoxSizer(wx.VERTICAL) sizer_2 = wx.BoxSizer(wx.VERTICAL) sizer_2.Add(self.text_ctrl_1, 1, wx.EXPAND|wx.ADJUST_MINSIZE, 0) sizer_2.Add(self.button_1, 0, wx.EXPAND|wx.ADJUST_MINSIZE, 0) sizer_1.Add(sizer_2, 1, wx.EXPAND, 0) self.SetSizer(sizer_1) sizer_1.Fit(self) self.Layout() # end wxGlade def MainToSecond(self, event): # wxGlade: MyMainFrame.<event_handler> MySecondFrame(self).Show() MySecondFrame.text_ctrl_2.SetValue("This text was generated from the 'MainFrame' window") # end of class MyMainFrame class MySecondFrame(wx.Frame): def __init__(self, *args, **kwds): # begin wxGlade: MySecondFrame.__init__ kwds["style"] = wx.DEFAULT_FRAME_STYLE wx.Frame.__init__(self, *args, **kwds) self.text_ctrl_2 = wx.TextCtrl(self, -1, "", style=wx.TE_MULTILINE) self.button_2 = wx.Button(self, -1, "Click me to close this frame and send some text back to the MainFrame") self.__set_properties() self.__do_layout() # end wxGlade def __set_properties(self): # begin wxGlade: MySecondFrame.__set_properties self.SetTitle("Frame Number Two") # end wxGlade def __do_layout(self): # begin wxGlade: MySecondFrame.__do_layout sizer_3 = wx.BoxSizer(wx.HORIZONTAL) sizer_4 = wx.BoxSizer(wx.VERTICAL) sizer_4.Add(self.text_ctrl_2, 1, wx.EXPAND|wx.ADJUST_MINSIZE, 0) sizer_4.Add(self.button_2, 0, wx.EXPAND|wx.ADJUST_MINSIZE, 0) sizer_3.Add(sizer_4, 1, wx.EXPAND, 0) self.SetSizer(sizer_3) sizer_3.Fit(self) self.Layout() # end wxGlade # end of class MySecondFrame if __name__ == "__main__": app = wx.PySimpleApp(0) wx.InitAllImageHandlers() frame_1 = MyMainFrame(None, -1, "") app.SetTopWindow(frame_1) frame_1.Show() app.MainLoop()

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Having trouble with a component of the random module
by Alan Gilfoy Aug. 31, 2008

Aug. 31, 2008

One of my for-fun Python products is a booster-pack generator for trading card games (specifically, Magic the Gathering, the one game of the genre that I play heavily) Somewhat like baseball cards, the cards in a pack are a somewhat-random selection of cards from the set in question, broken down by rarity levels. There are anywhere from two to six rarity levels/groupings per set; this depends on the set in question. I have a function for 2-list sets, another for 3, another for 4, another for 5, and another for 6. By lists I mean the following: If a set has, say, 2 rarity levels in it, I make 2 lists, one per rarity level. Each list is a text file that has the names of each card of that rarity level in that set, one per line. (There are no blank lines.) My function is set up kind of like this: Import the lists - via open("filename.txt").readlines() This action creates a List, with strings as the list elements, one string/element for each line of the imported text file I use random.sample to make the selection, random.sample(population, k) " for card in random.sample(Common, C): print card " Common is the 1st list, with the names of the commons in the set as the items in that list. The C variable is an integer, the amount of commons in a booster pack of that set. Say, if there are 11 commons in a booster pack of that set, I feed 11 as the value for C, and the code snippet above proceeds to print 11 randomly-selected names from the Commons list My program does the same thing for the second list (Uncommon), the third list (Rare), the fourth list (BasicLand), the fifth list (SpecialA), and the sixth list (SpecialB). For card sets that use two, three, or four lists, the results are displayed just fine. For card sets that use five or six lists, the results for the first four are displayed just fine, and then I get this: The code that processes the 1st, 2nd, 3rd and 4th lists is very similar to the code that processes the 5th and 6th, so I don't see what's happening. Traceback (most recent call last): File "C:\Documents and Settings\Alan\My Documents\_Alan_Programming\trunk\BoosterPackMaker\BoosterPackMaker.py", line 104, in <module> SixList_PackChooser(C_list, UC_list, R_list, BL_list, SpecialA_list, SpecialB_list, C, UC, R, BL, SA, SB) File "C:\Documents and Settings\Alan\My Documents\_Alan_Programming\trunk\BoosterPackMaker\PackGenerator.py", line 367, in SixList_PackChooser for card in random.sample(SpecialA, SA): File "C:\Python25\lib\random.py", line 303, in sample raise ValueError, "sample larger than population" ValueError: sample larger than population Looking at the mentioned line in random.py, I don't see how my program is triggering the ValueError. The number of items I want from a list is smaller than the population (number of items) in the list, so it should work. In this specific case, I'm asking for one item from a five-item list. Overall, more code is involved that I think can be represented in a few cut'n'paste snippets; how would I go about providing the files in question for interested parties to look at? (There's the Python file for my front-end UI code, the Python module file for my processing function, and the relevant text files) Apologizing for message length; I'm just trying to clearly explain the problem that I want assistance on.

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Re: [Tutor] dynamic argument lists
by Lie Ryan Aug. 30, 2008

Aug. 30, 2008

On Sat, 2008-08-30 at 12:00 +0200, tutor-request(a)python.org wrote: > > Message: 2 > Date: Sat, 30 Aug 2008 10:09:36 +0100 > From: eShopping <etrade.griffiths(a)dsl.pipex.com> > Subject: Re: [Tutor] dynamic argument lists > To: tutor(a)python.org > Message-ID: <72l93j$28l2h8(a)smtp.pipex.tiscali.co.uk> > Content-Type: text/plain; charset=us-ascii; format=flowed; > x-avg-checked=avg-ok-571D6DEA > > Bob, Kent > > thanks for the suggestions. Bob made the comment "If there is no > compelling requirement that myfunc's argument be in the form **kwargs > ...", but I'm afraid I don't understand the difference between > > myfunc (**kwargs) > > and > > myfunc (kwargs) > > Would someone mind explaining this? I never managed to find a > satisfactory explanation for what "**" means! First you have to understand what ** in a function definition means: def func(positionalArg, *excessPositionalArg, **excessNamedArg): ... positionalArg is the regular arguments you use, it is accessible by placing arguments at their respective position and the name it is assigned to, e.g. def func1(arg1, arg2, arg3): print arg1, arg2, arg3 func1(1, 2, 3) # 1 2 3 func1(1, 2, 3, 4) # Wrong number of argument Error func1(1, arg3 = 2, arg2 = 3) # 1 3 2 excessPositionalArg is a list of positional arguments that doesn't fit in the regular positional argument, e.g. def func2(arg1, arg2, *epa): for arg in epa: print arg, func2(1, 2, 3, 4, 5, 6, 7) # 3 4 5 6 7 last, is excessNamedArg. As we have learned, there are two ways to access an argument, by its position and by its names, excessNamedArgument is a dictionary containing the named arguments that aren't explicitly specified in the function definition, e.g. def func3(arg1, arg2, *args, **kargs): print arg1, arg2, for arg in args: print '[1 -- %s]' % arg, for key, value in kargs: print '[2 -- %s: %s]' % (key, value) func3(1, 2, otherargs = 10): # 1 2 [2 -- otherargs: 10] func3(1, arg2 = 2, otherargs1 = 10, otherargs2 = 20) # 1 2 [2 -- otherargs1: 10] # [2 -- otherargs2: 20] Now, to the question, then what is this: d = {'a':10, 'b':20, arg2: 30} func3(1, **d) # 1 30 [2 -- a: 10] # [2 -- b: 20] compare: func3(1, 2, d) # 1 2 [1 -- {'a':10, 'b':20, arg2: 30}] If you called it like func3(1, 2, **d), and d is a dictionary, then d would be expanded and its key/value pair be considered as named arguments to the function. OTOH, func3(1, 2, d) would pass the whole dictionary to func3. Since in this case, we have declared a container for excessPositionalArgument, d is treated as excessPositionalArgument, if we haven't done that, an bad number of argument error would occur because there is no more positional argument left.

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