🌐 Mailman 3 April 2007 - Tutor - python.org

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.

5 6

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

4 3

difflib.SequenceMatcher with get_matching_blocks is incorrect
by Thomas Nov. 5, 2007

Nov. 5, 2007

I'm trying to write a program to test someone's typing speed and show them their mistakes. However I'm getting weird results when looking for the differences in longer (than 100 chars) strings: import difflib # a tape measure string (just makes it easier to locate a given index) a = '1-3-5-7-9-12-15-18-21-24-27-30-33-36-39-42-45-48-51-54-57-60-63-66-69-72-75-78-81-84-87-90-93-96-99-103-107-111-115-119-123-127-131-135-139-143-147-151-155-159-163-167-171-175-179-183-187-191-195--200' # now with a few mistakes b = '1-3-5-7-l-12-15-18-21-24-27-30-33-36-39o42-45-48-51-54-57-60-63-66-69-72-75-78-81-84-8k-90-93-96-9l-103-107-111-115-119-12b-1v7-131-135-139-143-147-151-m55-159-163-167-a71-175j179-183-187-191-195--200' s = difflib.SequenceMatcher(None, a ,b) ms = s.get_matching_blocks() print ms [(0, 0, 8), (200, 200, 0)] Have I made a mistake or is this function designed to give up when the input strings get too long? Thanks in advance, Thomas

2 1

ossaudiodev, pygtk, and flushing buffers
by Matthew White Aug. 3, 2007

Aug. 3, 2007

Hello All, I'm writing a little audio player that plays voicemail files. (I realize I'm reinventing the wheel, but it's still fun.) The problem I'm experiencing is that I'm hearing the last fraction of the sound clip twice, either when the clip is done playing or when the program exits. I've tried a few things and none of them have worked. The bit of code that does the playing is here: def play(self): if self.data_written < self.file_length: buf = self.data.read(self.buf_size) self.data_written += self.dsp.write(buf) self.percent_done = self.data_written / self.file_length if self.data_written == self.file_length: self._reopen_audio_device() This causes the second playing of the "last little bit" when the end of the file is reached. When I don't include the second if statement, the "last little bit" gets played when the program exits. According to the documentaiton, closing the audio device will flush any data in the sound card buffer. I guess what I'm hearing is that buffered clip being flushed. I've thought about using the mixer device to put the volume to zero, flush the buffer, then turning the volume back up again, but that seems like a hack. If anyone decides to use this program, you'll need to use a .wav file and change the value of self.sample_rate in vmPlayer.py from 8000 to 44100 (or whatever rate your file is encoded in) (Also, I plan on auto-detecting the sample rate in the future. I hard coded 8000 because that's the rate the voice mail system uses.) See attached files for the code. -mtw

3 3

SPE - Stani's Python Editor ?
by Vladimir Strycek June 24, 2007

June 24, 2007

Hi all, some time ago i instaled SPE with python 2.4... it works very good... but yesterday my pc crash completly ( some dll went missing somehow :-) )... so after format and reinstalling of windows i begin to install all my programs back... When i come to python i download new 2.5 version and only version for win i could find is SPE-0.8.2.a-wx2.6.1.0-py24 which doesnt work... :-( newer version ist just rpm and i need exe for win... any idea if there will be exe or any more development in SPE cause homepage is not running etc... Or can you suggest similar IDE for python... ? Thanks Best regards Vladimir

6 5

best way to tell if i am connected to the internet
by shawn bright May 1, 2007

May 1, 2007

hello there all, i am wondering, what would be the simplest way to get a true/false am i connected to the internet ? right now i am using httplib to fetch a webpage every 20 minutes to see, but i am thinking that there is a better way, any suggestions would be encouraging thanks shawn

3 4

Fwd: iterating
by Cecilia Alm April 30, 2007

April 30, 2007

2007/4/30, Kent Johnson <kent37(a)tds.net>: . Also if you are adding or deleting from the dict > during the iteration then dict.keys() is safer because the list of keys > is created before the add and delete. Thanks for the response; by adding and deleting, I assume you refer to adding or deleting keys (rather than changing the value associated with the key). -- E. Cecilia Alm Graduate student, Dept. of Linguistics, UIUC Office: 2013 Beckman Institute -- E. Cecilia Alm Graduate student, Dept. of Linguistics, UIUC Office: 2013 Beckman Institute

2 1

StringIO and dictionaries
by Necmettin Begiter April 30, 2007

April 30, 2007

I want to run an external python script inside my script. So here is what I came up with: Print codename for testing purposes. Define an empty dictionary. Read the file. Do StringIO assignments and run the code. Get the outputs and append them to the dictionary. Print the outputs for testing purposes. The code: codeOut= {} codeErr= {} Print codename for testing purposes: print codename Note: codename is a parameter that is passed to the function for the first parts (keys) of codeOut and codeErr dictionaries; and it prints the given name (deneme in this case) correctly. Read the file: localfile= open(filename,'r') code2run= localfile.readlines() localfile.close() Do StringIO assignments and run the code: codOut= StringIO.StringIO() codErr= StringIO.StringIO() sys.stdout= codOut sys.stderr= codErr exec code2run sys.stdout= sys.__stdout__ sys.stderr= sys.__stderr__ Get the outputs and append them to the dictionary. erroroutput= codErr.getvalue() normaloutput= codOut.getvalue() codeOut.append({codename:erroroutput}) codeErr.append({codename:normaloutput}) Print the outputs (just for testing): print codename print normaloutput print erroroutput print codeOut print codeErr And I get nothing. Is there something I am doing wrong? Because I have read the parts on dictionaries and stringio and googled, but I can't find the problem. Any comments, suggestions? Or could someone please tell me if there is something wrong with my code? -- Necmettin Begiter Blog: http://begiter.blogspot.com/feeds/posts/default

2 1

iterating
by Cecilia Alm April 30, 2007

April 30, 2007

1) Unordered maps/collections like sets and dictionaries also seem to support iterating over set members or dictionary keys with "for x in y" syntax. As far as I can tell, the following three ways generally behave the same way, or is there a difference in behavior between: a) for key in dictionary: b) for key in dictionary.keys(): c) mykeys = dictionary.keys() for k in mykeys: 2) The following three ways for manipulating objects in a list with a function will generally do the same thing, right? (but the last two have a shorter syntax). a) newls = [] for entry in mylist: newls.append(function(entry)) b) newlist = map(function, mylist) c) newlist = [function(entry) for entry in mylist]

2 1

Problem with "Hello, World"
by Alexander Dering April 30, 2007

April 30, 2007

So I've written my first python program (the ubiquitous 'Hello, World'). Already, I'm having problems. First, the question I can't find the answer to. Where (exactly) am I supposed to save my files? When I wrote "hello.py" there was no clearly stated "Make sure you save it HERE or else Python won't know where to look for it." In case that won't solve the problem, here are the gory details. I wrote "hello.py" with TextWrangler. I can get it to run from TextWrangler by clicking on the "run in terminal" command. And it runs beautifully. A masterful demonstration of my ability to follow directions. But I can't get it to run directly from Python. If I go to the terminal and type "python hello.py" (which is what the instructions say I should be doing!) I get the following: >>> hello.py Traceback (most recent call last): File "<stdin>", line 1, in ? NameError: name 'hello' is not defined >>> When I run debugger (in TextWrangler) I get the following: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/pdb.py", line 9, in ? import cmd File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/cmd.py", line 48, in ? import string File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/string.py", line 83, in ? import re as _re File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/re.py", line 5, in ? from sre import * File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/sre.py", line 97, in ? import sre_compile File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/sre_compile.py", line 17, in ? assert _sre.MAGIC == MAGIC, "SRE module mismatch" AssertionError: SRE module mismatch logout [Process completed] All help gratefully taken with both hands! Alex

2 1