🌐 Mailman 3 October 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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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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new turtle module
by roberto Nov. 16, 2010

Nov. 16, 2010

hello, i want to use the turtle module described in http://docs.python.org/library/turtle.html since the module in my python2.5 is a little bit outdated; is it correct to overwrite the turtle.py and turtle.pyc files in my current '/usr/lib/python2.5/lib-tk/' directory with the ones holding the same names unzipped from turtleDemo folder 'TurtleDemo-Python2.x' by author Gregor Lindl ? Thank you ! -- roberto

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Networking
by Chris King Nov. 9, 2010

Nov. 9, 2010

Dear Tutors, I have attached my 2 programs for networking. It uses socket and SocketServer, but it just simplifies it even more. The problem is it won't work. The Client raises the error, (with trace back) Traceback (most recent call last): File "G:\My Dropbox\My Dropbox\Chris\Not done\client.py", line 34, in <module> print client.recv() File "G:\My Dropbox\My Dropbox\Chris\Not done\client.py", line 16, in recv return self.__sock.recv(1024) error: [Errno 10053] An established connection was aborted by the software in your host machine The server seems to get an error of some sort, but also seems to catch and print it. It prints ---------------------------------------- Exception happened during processing of request from ('127.0.0.1', 1424) Traceback (most recent call last): File "C:\Python26\lib\SocketServer.py", line 281, in _handle_request_noblock self.process_request(request, client_address) File "C:\Python26\lib\SocketServer.py", line 307, in process_request self.finish_request(request, client_address) File "C:\Python26\lib\SocketServer.py", line 320, in finish_request self.RequestHandlerClass(request, client_address, self) TypeError: 'NoneType' object is not callable ---------------------------------------- I look at both of the documentations of socket and SocketServer, but I couldn't firgue it out. I don't know much about networking. Please Help Sincerely, Me

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Problems with partial string matching
by Josep M. Fontana Nov. 2, 2010

Nov. 2, 2010

Hi, As I said in another message with the heading "Using contents of a document to change file names", I'm trying to learn Python "by doing" and I was working on a little project where I had to change the names of the files in a directory according to some codes contained in a CSV file. With the help of the participants in this list I managed to overcome some of the first obstacles I found and managed to create a dictionary out of the structured contents of the CSV file. Unfortunately, I didn't have much time to continue working on my project and I didn't get back to the script until now. I have encountered another hurdle, though, which doesn't allow me to go on. The problem might be *very* simple to solve but I've spent the last couple of hours checking manuals and doing searches on the internet without having much success. What I'm trying to do now is to use the dictionary I created (with entries such as {'I-02': '1399', 'I-01': '1374',...}) to iterate over the file names I want to change and do the necessary string substitutions. If one of the keys in the dictionary matches the code that is found at the beginning of every file, then the value of the dictionary representing the year in which the text was written is appended at the end of the file name. Here is what I've done so far: ------------------------------ import os, sys, glob, re fileNameYear = open(r'/Volumes/DATA/Documents/workspace/GCA/CORPUS_TEXT_LATIN_1/FileNameYear.txt', "U").readlines() name_year = {} for line in fileNameYear: #File objects have built-in iteration name, year = line.strip().split(',') name_year[name] = year #effectively creates the dictionary by creating keys with the element 'name' returned by the loop and assigning them values corresponding to the element 'year' --> !d[key] = value" means Set d[key] to value. os.getcwd() os.chdir('/Volumes/DATA/Documents/workspace/GCA/CORPUS_TEXT_LATIN_1') file_names = glob.glob('*.txt') for name_of_file in file_names: if name_of_file.startswith(name): re.sub('__', '__' + year, name_of_file) #The files have names such as 'B-13-Viatges_Marco_Polo__.txt' so the first argument in re.sub() is the string '__' which should be replaced by the same string followed by the string corresponding to the year value in the dictionary (also a string) ------------------------------ I run this and I don't get any errors. The names of the files in the directory, however, are not changed. What am I doing wrong? As always, your help is greatly appreciated. Josep M.

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