🌐 Mailman 3 December 2010 - 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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Running .py files in shell
by Kevin Rapley Sept. 22, 2011

Sept. 22, 2011

Hello all, I am new to programming and have opted to learn Python as I hear it is a good first language. I am currently going through the exercises in 'How to Think Like a Computer Scientist: Learning with Python 2nd Edition'. I am running Mac OSX v10.6.4 Snow Leopard I am running Python 2.6.1 I have a couple of questions: 1. How do I execute .py files in the command line shell? I have my files in /Users/Kevin/python-exercises/ and am opening python in shell from that directory 2. How do I install GASP which is referenced in chapter 4? The instructions in this book are not complete. I have researched and found a reference on Stack Overflow which is contributed to by GASP programmers http://stackoverflow.com/questions/1024862/how-do-i-install-gasp-for-python… I have MacPorts installed and have attempted to install PyObjC, which is referenced as a prerequisite to PyGame and GASP. I get the following error when attempting to install PyObjC: sudo port install py-pyobjc Password: ---> Computing dependencies for py-pyobjc ---> Fetching py-pyobjc Error: Target org.macports.fetch returned: PyObjC 1.4 is for Mac OS X 10.4 and lower. On 10.5, use py-pyobjc2 instead. Log for py-pyobjc is at: /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_ports_python_py-pyobjc/main.log Error: Status 1 encountered during processing. It says to use py-objc2 instead, so I do so and get this error: sudo port install py-pyobjc2 Error: Target org.macports.activate returned: Image error: /opt/local/lib/python2.4/site-packages/modulegraph/__init__.py is being used by the active py-modulegraph port. Please deactivate this port first, or use 'port -f activate py-modulegraph-devel' to force the activation. Log for py-modulegraph-devel is at: /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_ports_python_py-modulegraph-devel/main.log Error: The following dependencies failed to build: py-py2app-devel py-modulegraph-devel Error: Status 1 encountered during processing. To report a bug, see <http://guide.macports.org/#project.tickets> I attempted to correct the issue by entering the following: port -f activate py-modulegraph-devel But it returned this error: Warning: Failed to open Portfile from registry for py-modulegraph-devel @0.7.2_0 ---> Activating py-modulegraph-devel Error: port activate failed: sqlite error: attempt to write a readonly database (8) This is as far as I have got with resolving this issue so far. All help and guidance will be greatly appreciated. Kevin Rapley

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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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2to3 conversion
by Zubin Mithra July 1, 2011

July 1, 2011

Hey everyone, I was running 2to3 on a particular file and I got the following traceback( http://paste.pocoo.org/show/223468/). The file which I was attempting to convert can be viewed here( http://paste.pocoo.org/show/223469/). Any pointers on what needs to be done? Thanks in advance, Zubin

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sftp get single file
by Matt Herzog June 22, 2011

June 22, 2011

Hello All. I need to use paramiko to sftp get a single file from a remote server. The remote file's base name will be today's date (%Y%m%d) dot tab. I need help joining the today with the .tab extension. Do I need globbing? example: 20090716.tab #!/usr/bin/env python import paramiko import glob import os import time hostname = 'sftp.booboo.com' port = 22 username = 'booboo' password = '07N4219?' # glob_pattern='*.tab' today = time.strftime("%Y%m%d") remotepath = today.tab localpath = '/home/data/text' if __name__ == "__main__": t = paramiko.Transport((hostname, port)) t.connect(username=username, password=password) sftp = paramiko.SFTPClient.from_transport(t) sftp.get(remotepath, localpath) t.close() -- I fear you speak upon the rack, Where men enforced do speak anything. - William Shakespeare

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Plotting a Linear Equation
by Corey Richardson April 21, 2011

April 21, 2011

Hello tutors. Probably the wrong mailing list, but someone might know. I want to use matplotlib (or similar) to plot an equation in slope-intercept (y=mx+b) or standard form (Ax + By = C). As far as I've read and tested, you can only plot with a series of points. I could make two points out of those manually, but I was wondering if anyone knew of an easier way. Thanks.

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Beginning Python and other resources (was Re: Slicing Tuples)
by David Jan. 13, 2011

Jan. 13, 2011

On 12 December 2010 03:25, John Russell <thor(a)othala.us> wrote: > Last night I started working through a book (Beginning Python: Using Python > 2.6 and Python 3.1) I bought to learn Python, and there is an example in it > that doesn't make sense to me. I have that book too, and several others thankfully. I'm just writing to share my experience, in case another perspective from another relatively new python user is helpful to anyone. I found that book is written towards a friendly beginner level, but it omits many details and is not a comprehensive reference. It does include plenty of examples on many topics. I have read the opposite criticism of other books, so it is probably impossible for one book to fit all needs. Personally I became weary of the food/fridge/kitchen theme of the early examples as it did not engage my interest at all, and there is so much of it. However I have found that book valuable for its Part III where it covers useful applications. Although I have come to expect that its examples will often need typos corrected or other small modifications to get them to run properly on Python 2.6. So while working through Parts I and II, if your experience is anything like mine where I moved away from it fairly quickly, you will definitely need other resources. Fortunately they are abundantly available. In case you are unaware, a Tutorial and Reference are integrated with Python. On my Linux box the tutorial is file:///usr/share/doc/python-docs-x.x.x/html/tutorial/index.html and the Alphabetic Index to the Reference is file:///usr/share/doc/python-docs-x.x.x/html/genindex.html I find the Tutorial easily readable, whereas the Reference can be challenging, but it is comprehensive and likely contains the answer to most questions, somewhere. As an exercise I thought I'd try to find the answer to your question using these built-in docs. The keyword is "slice" which we know from the book. I couldn't find any coverage in the 2.6 tutorial so I looked up "slice" in the Alphabetic Index, and the first link took me to a section which includes the answer: "The slicing now selects all items with index k such that i <= k < j where i and j are the specified lower and upper bounds". In case you are not aware, the web has a vast amount of great material for learning Python, see for example: http://wiki.python.org/moin/BeginnersGuide/NonProgrammers As Python is an evolving language, one needs be mindful of the differences between Python 2.x and Python 3.x when using this material. My favourite Python book of my small beginners collection is "Python 3 Object Oriented Programming" by Dusty Phillips. It claims: "If you're new to object-oriented programming techniques, or if you have basic Python skills, and wish to learn in depth how and when to correctly apply object-oriented programming in Python, this is the book for you". I endorse that completely. Having learned the syntax basics elsewhere, for me this is a book like no other. I find its topic coverage and all its short examples consistently useful, powerful, and illuminating. I find it easy to read, well matched to my level and interest, and it has made a real difference to the code I write. I use classes with confidence now. For example, it gave me the background and confidence to design a custom sortable abstract class I needed, my first personal experience of the power of OOP. Tthe python and tutorial mailing lists are a wonderul resource as you are obviously aware. Thanks to all the contributors from whom I continue to learn.

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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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Re: [Tutor] Python 2.7.1 interpreter
by Frank Chang Dec. 30, 2010

Dec. 30, 2010

I wanted to thank Steven D'Aprano and Allan Gauld for solving my Python 2.7.1 interpreter question in Tutor Digest Vol. 82 Issue 121. Thank you for yor help.

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Problem installing pyaudiere
by Danci Emanuel Dec. 30, 2010

Dec. 30, 2010

Hello! I am trying to install the pyaudiere package on linux and I get the following error: " AudioDevice.h:6: fatal error: audiere.h: No such file or directorycompilation terminated. " I am interested if anyone managed to solve this problem or if someone could suggest a package that could replace pyaudiere. Thanks,Emanuel DANCI

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