Fifth Fredericksburg, VA ZPUG Meeting
Please join us October 12, 7:30-9:00 PM, for the fifth meeting of the Fredericksburg, VA Zope and Python User Group (ZPUG). Learn about Python configuration of Asterisk, an open source VOIP! Free food! Rob Page, Zope Corporation CEO and President, will present a technical session on Asterisk [1] installation, configuration and operation. A brief discussion of connections to the public telephone network and internet telephony providers will be presented. Hadar Pedhazur, Zope Corporation Chairman of the Board, will present a technical session on call handling and processing using Python extensions to Asterisk. We will also serve delicious fruit, cheese, and soft drinks. We've had a nice group for all the meetings. Please come and bring friends! We also are now members of the O'Reilly and Apress user group programs, which gives us nice book discounts (prices better than Amazon's, for instance) and the possibility of free review copies. Ask me about details at the meeting if you are interested. General ZPUG information When: second Wednesday of every month, 7:30-9:00. Where: Zope Corporation offices. 513 Prince Edward Street; Fredericksburg, VA 22408 (tinyurl for map is http://tinyurl.com/duoab). Parking: Zope Corporation parking lot; entrance on Prince Edward Street. Topics: As desired (and offered) by participants, within the constraints of having to do with Python. Contact: Gary Poster ([EMAIL PROTECTED]) [1] From www.asterisk.org: Asterisk is a complete PBX in software. It runs on Linux, BSD and MacOSX and provides all of the features you would expect from a PBX and more. Asterisk does voice over IP in many protocols, and can interoperate with almost all standards-based telephony equipment using relatively inexpensive hardware. Asterisk provides Voicemail services with Directory, Call Conferencing, Interactive Voice Response and Call Queuing. It has support for three-way calling, caller ID services, ADSI, SIP and H. 323 (as both client and gateway). Check the Features section for a more complete list. Asterisk needs no additional hardware for Voice over IP. For interconnection with digital and analog telephony equipment, Asterisk supports a number of hardware devices, most notably all of the hardware manufactured by Asterisk's sponsors, Digium™. Digium has single and quad span T1 and E1 interfaces for interconnection to PRI lines and channel banks as well as a single port FXO card and a one to four-port modular FXS and FXO card. -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
REMINDER: BayPIGgies: October 13, 7:30pm (IronPort)
The next meeting of BayPIGgies will be Thurs, October 13 at 7:30pm at IronPort. Tim Thompson will describe and demonstrate the interaction between Burning Man and Python using two applications, Radio Free Quasar and Ergo. BayPIGgies meetings alternate between IronPort (San Bruno, California) and Google (Mountain View, California). For more information and directions, see http://www.baypiggies.net/ Before the meeting, we sometimes meet at 6pm for dinner. Discussion of dinner plans is handled on the BayPIGgies mailing list. Advance notice: We've got some options on the plate for November 10 but haven't settled anything yet. Please send e-mail to [EMAIL PROTECTED] if you want to suggest an agenda (or volunteer to give a presentation). The meeting agenda for December 8 has been set. -- Aahz ([EMAIL PROTECTED]) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Batteries Included?
One of the first things I wanted to do when I start learning Python was to produce a simple standalone application that I could distribute to my users (windows users). Python's moto is Batteries Included, but where are the batteries for making exe files and making an installer file? I had to download, install and use py2exe and Inno Setup in order to accomplish this. I might be wrong expecting that a language whose moto is Batteries Included would be able to produce exe files. Are there plans to do this in the future version of Python? Alex -- http://mail.python.org/mailman/listinfo/python-list
Let My Terminal Go
Hello, A user of my application points me to a behavior in gVim, the text editor, that I would like to implement in my application. When gVim is launched from a shell terminal, it completely frees the terminal. You can continue to use the terminal for whatever purpose you wish, including closing and exiting it, without any effect on the running gVim instance. How do I implement this in my application written in python? I would like to believe it does not involve me forking my application in a new process. Maybe there is signal I can send to the operating system to achieve this, right? Your help is appreciated. Thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: [Info] PEP 308 accepted - new conditional expressions
Dave Hansen wrote: And Basic, and Fortran, and Lisp, and just about any programming language you care to name, including python (if Condition: Affirmative else: Negative). Not to mention that the sequence is identical to execution order. It's just plain goofy to have to scan to the middle of an expression to find out what happens first, then depending on the result of that, skipping back over what you just skipped. 1 word: Perl FWIW, in over 20 years of C programming, I use it pretty rarely too, though I never had to look it up after I first saw it in KR. It only very rarely holds any advantage over a simple if/else statement, especially in modern compilers. It's most useful in macros, which python doesn't even have. same time span and I used it zillions of times ==eric -- http://mail.python.org/mailman/listinfo/python-list
Re: how to capture key pressing
billie [EMAIL PROTECTED] wrote: Look at curses. I was searching for something portable on multiple platforms. Keyboard access is not portable. It is quite system-specific, even in C. Curses doesn't work on Windows. Sure it does. You can find curses implementations for Windows. However, it depends on what you are planning to do. If all you want to do is wait for one character and print it, it's not too hard to have separate schemes for separate systems: C:\Data\PyToolspython Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit (Intel)] on win32 Type help, copyright, credits or license for more information. import msvcrt msvcrt.getch() '\x1b' (I pressed escape after the second enter.) -- - Tim Roberts, [EMAIL PROTECTED] Providenza Boekelheide, Inc. -- http://mail.python.org/mailman/listinfo/python-list
Re: Let My Terminal Go
On Mon, 2005-10-10 at 22:58 -0700, [EMAIL PROTECTED] wrote: Hello, A user of my application points me to a behavior in gVim, the text editor, that I would like to implement in my application. When gVim is launched from a shell terminal, it completely frees the terminal. You can continue to use the terminal for whatever purpose you wish, including closing and exiting it, without any effect on the running gVim instance. How do I implement this in my application written in python? I would like to believe it does not involve me forking my application in a new process. Maybe there is signal I can send to the operating system to achieve this, right? gvim forks. Why do you want to avoid it? import os, sys pid = os.fork() if pid !=0: # exit parent sys.exit(0) # child continues -- http://mail.python.org/mailman/listinfo/python-list
Re: Batteries Included?
Alex enlightened us with: Python's moto is Batteries Included, but where are the batteries for making exe files and making an installer file? Those aren't batteries. Those are things you can do with the program, but are outside the programming language. Writing and distributing software is one thing. Converting them to a platform-specific executable is another. I had to download, install and use py2exe and Inno Setup in order to accomplish this. Well done. I might be wrong expecting that a language whose moto is Batteries Included would be able to produce exe files. Indeed, you're wrong. Why would such an ability be included in Python? It's a cross platform language. What need would Mac, Linux, BSD, Solaris etc. users have for such a feature? And why would it have to be included, when there is an easy solution just around the corner? You prooved that it was easy enough to install and use by someone who just learned Python. I really don't see the problem here. Are there plans to do this in the future version of Python? I doubt it. Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: Let My Terminal Go
[EMAIL PROTECTED] enlightened us with: When gVim is launched from a shell terminal, it completely frees the terminal. [...] How do I implement this in my application written in python? Using fork() and by catching the HUP signal. Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for info on Python's memory allocation
Steven D'Aprano enlightened us with: he says that every time you try to append to a list that is already full, Python doubles the size of the list. This wastes no more than 50% of the memory needed for that list, but has various advantages -- and I'm damned if I can remember exactly what those advantages were. Allocating extra memory usually requires the following steps: - Allocate more memory - Copy all data from old to new memory - Deallocate old memory That second step requires N actions if there are N data items in the list. If you add one 'block' of memory to the list for each item you add, you waste no memory, but every item added requires N steps to copy all the old items. That means that after you've added N items, N**2 steps have been taken. That's very bad for performance. If, on the other hand, you double the memory every time you run out, you have to copy much less data, and in the end it turns out you need roughly N steps to add N items to the list. That's a lot better, isn't it? Sybren -- The problem with the world is stupidity. Not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself? Frank Zappa -- http://mail.python.org/mailman/listinfo/python-list
Re: Send password over TCP connection
dcrespo wrote: ¡Beautiful and elegant solution! Two copies of the password: one on the client, the other on the server. 1. Client wants to connect 2. Server generates a random_alphanumeric_string and sends it to the client 3. Both Client and Server creates a hash string from password+random_alphanumeric_string 4. Client sends the hash string to the server 5. Server compares his hash result with the hash string received from de client. I think it is a very good solution, Isn't it? In fact this is almost an OTP but be aware! A man-in-the-middle attack can crack your algorithm. This is beacuse you create a random string only on one side. You cannot trust in the connection you are using. You can modify you algorigthm to be more secure: 1. Client wants to connect 2. Server generates a server_random_alphanumeric_string and sends it to the client 3. Client generates a client_random_alphanumeric_string and sends it to the client too 3. Both Client and Server creates a hash string from server_random_alphanumeric_string+password+client_random_alphanumeric_string 4. Client sends the hash string to the server 5. Server compares his hash result with the hash string received from de client. This is only a bit difference, but is makes sense. An intuder (who knows the your algorithm, because getting the code is not as difficult) could make a fake server to you, and send back HIS string (that is not random). Suppose we have a weakness in the hash function. The intuder can exploit this weakness by sending you his special string. The modified version has the advantage of sending two random strings, this way the intuder cannot take advantage of possible hash function weaknesses, because the hash function will be called on a string that is random for sure. Best, Les -- http://mail.python.org/mailman/listinfo/python-list
Re: Batteries Included?
Alex [EMAIL PROTECTED] writes: One of the first things I wanted to do when I start learning Python was to produce a simple standalone application that I could distribute to my users (windows users). Python's moto is Batteries Included, but where are the batteries for making exe files and making an installer file? I had to download, install and use py2exe and Inno Setup in order to accomplish this. I might be wrong expecting that a language whose moto is Batteries Included would be able to produce exe files. Are there plans to do this in the future version of Python? Did you try looking through the distutils docs? After you create a setup.py file for you program, doing python setup.py bdist --formats=wininst should do the trick. Of course, I don't own a Windows box, so I can't check it, but when I ask a setup file for help on formats, it tells me the wininst format is a windows installer. Personally, I think of building a platform-specific bundle for distribution to end users as more along the lines of shipping than batteries. Python comes with lots of tools to help you get your application working - the batteries. Once it's working, you don't need batteries: you need wrapping paper, and a box, and tape, and so on. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: Send password over TCP connection
Ignoring all the other issues, any solution which actually requires the password to be stored on the server is a bad solution. Administrators should not have access to user passwords, and in addition users should not be put in the position of having to trust your server-side security to keep their passwords (which they might have used on other systems) from being grabbed by hackers. Users will always need to trust in the server. The authentication process ensures that the client is really talking with the desired server and vice versa. But even if you know that you are talking to the right server, you need to trust in the server. The administrator of the server has access to all data. Possibly other persons and softwares too. Passwords are not different from this point of view. Les -- http://mail.python.org/mailman/listinfo/python-list
Re: Batteries Included?
Sybren Stuvel [EMAIL PROTECTED] writes: I might be wrong expecting that a language whose moto is Batteries Included would be able to produce exe files. Indeed, you're wrong. Why would such an ability be included in Python? distutils.exe, included in Python, in fact does have the ability to produce .exe files, just not completely general ones. It's a cross platform language. What need would Mac, Linux, BSD, Solaris etc. users have for such a feature? The same need that they have for msvcrt, winreg, winsound, or the SGI IRIX specific functions currently in the library. The same need that Windows users have for the Unix specific parts which are in the library. The same need that non-numeric programmers have for the cmath module, which is also in the library. And why would it have to be included, when there is an easy solution just around the corner? You prooved that it was easy enough to install and use by someone who just learned Python. I really don't see the problem here. Um, if the TV ad for some Walkman says batteries included and the batteries aren't included, you have legitimate reason to ask what's going on. That it's easy enough for you to go to the store and buy batteries separately is irrelevant. You didn't get what was advertised. Now a Windows .exe installer wasn't one of the advertised features of Python and maybe there's good reasons to leave it out, but its platform specificness is not one of those reasons. There's already plenty of platform specific stuff in Python. Personally I think including a .exe packager in Python would be a great idea. As a Linux user I can't easily run Windows-specific utilities like Inno Setup. So I don't have a good way to make .exe's from my Python code that Windows users can easily run. Having a cross platform .exe packager included with Python would be useful the same way cross compilers are useful. I'm using an x86 computer but I can easily configure gcc to produce ARM code. Why shouldn't my Linux Python installation be able to produce Windows .exe's? -- http://mail.python.org/mailman/listinfo/python-list
Re: Let My Terminal Go
[EMAIL PROTECTED] [EMAIL PROTECTED] writes: Hello, A user of my application points me to a behavior in gVim, the text editor, that I would like to implement in my application. When gVim is launched from a shell terminal, it completely frees the terminal. You can continue to use the terminal for whatever purpose you wish, including closing and exiting it, without any effect on the running gVim instance. How do I implement this in my application written in python? I would like to believe it does not involve me forking my application in a new process. Maybe there is signal I can send to the operating system to achieve this, right? Several things need to happen. First, you need to take yourself out of the session you are in. To do that, you use the setsid system call. This is available in python as os.setsid. Last, you need to detach your process from the terminal. You do that by closing all the file descriptors you have that reference it. stdin, stdout and stderr should do the trick. The standard trick is to set set them to /dev/null. This has to happen last, so that if there are problems in the second step, writing to stderr about it does some good. Second, you need to tell the shell that launched you that it can continue. The standard way to do this is to fork your process, and have the parent exit. That causes the parent shell to think your process is dead, and so forget about it completely. There are other ways to do this, but they aren't as reliable. The easy way to do all these things - from C, anyway - is with daemon(3). That isn't wrapped as part of the Python library. The easiest way to solve your problem may be write a wrapper for that call. If daemon exists on enough systems, submitting your wrapper as a patch to the os modulee would be appropriate. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: Batteries Included?
Mike Meyer: After you create a setup.py file for you program, doing python setup.py bdist --formats=wininst should do the trick. Of course, I don't own a Windows box, so I can't check it, but when I ask a setup file for help on formats, it tells me the wininst format is a windows installer. I can confirm that it works (for pure Python applications), since I did it. Michele Simionato -- http://mail.python.org/mailman/listinfo/python-list
Re: Send password over TCP connection
If you really want to do it right, use SRP, http://srp.stanford.edu. This is a bit offtopic here. I read the RFC and I do not see why SRP is not vulnerable to dictionary attacks. If I have a working client software then I can use it to reveal passwords. Isn't it a dictionary attack? Can you please enlighten me? Les -- http://mail.python.org/mailman/listinfo/python-list
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Re: Batteries Included?
I might be wrong expecting that a language whose moto is Batteries Included would be able to produce exe files. Are there plans to do this in the future version of Python? Yes, you are wrong expecting that. Creating an exe-cutable is windows specific and python _tries_ to be platform neutral. py2exe - a wonderful tool which I use myself - is a battery on the shelves. It can be easily picked from there. Furthermore it is not Python's philosophy to create exe-cutables. But I do understand your wish (being a Windows Developper at work myself) and Python is not a matter of course within Windows. Your best bet is ActiveState which bundles a windows specific version. Ask them, maybe they are willing to include it. Python should refrain from doing so. Before overloading the included batteries an approach as found in Perl (CPAN) should be adapted... eg. http://peak.telecommunity.com/DevCenter/EasyInstall Have a nice day, Marco -- http://mail.python.org/mailman/listinfo/python-list
Re: Send password over TCP connection
Laszlo Zsolt Nagy [EMAIL PROTECTED] writes: This is a bit offtopic here. I read the RFC and I do not see why SRP is not vulnerable to dictionary attacks. If I have a working client software then I can use it to reveal passwords. Isn't it a dictionary attack? Dictionary attack in this context means an eavesdropper records a session, then compares all the hashed passwords against a word list offline. If the attacker is allowed to make unlimited online queries, then he can guess at SRP passwords too. But the host should notice that and prevent it. -- http://mail.python.org/mailman/listinfo/python-list
Re: Question about StringIO
Benjamin Niemann wrote:
Frank Millman wrote:
I will try to explain my experience with popen() briefly.
I run through all the scripts and create a StringIO object with the
string I want to pass. It is about 250 000 bytes long. If I run psql
using popen(), and pass it the string via stdin, it works fine, but I
get all the messages on the screen. If I do the same, but end the
command with ' fjm 21' it works correctly and the messages end up
in the file fjm, which is about 40 000 bytes long. If I run it with
popen4(), it starts ok, but then hangs about 1/4 of the way through.
Exactly the same happens on MSW. It seems to be hitting a limit on the
size of the stdout file - is that possible?
That's probably a deadlock as described in
http://docs.python.org/lib/popen2-flow-control.html
Thanks for this pointer. I have read it, but I don't think it applies
to my situation, as it talks about 'reading' from the child's stdout
while the child is 'writing' to stderr. I am not doing that, or at
least not consciously. Here is a code snippet. 's' is a StringIO object
that contains my input. It is about 6000 lines/25 bytes long.
-
sql_stdin,sql_stdout = os.popen4('psql -U %s -d %s' % (user,database))
sql_stdin.writelines(s.readlines())
s.close()
sql_stdin.close()
-
It starts, and then hangs, after processing about 6% of my input.
If I add ' fjm 21' to the command, it works, so it is definitely
connected with the child writing to stdout/stderr.
I tried storing my input in a list, and passing ''.join(s), but it had
the same result. I also looped over the list and wrote one line at a
time to sql_stdin - same result.
I can work around this, so a solution is not critical. However, it
would be nice to know if this is a limitation of popen4(), or if I am
doing something wrong.
BTW, is there an equivalent of /dev/null on MSW?
Dunno - but as a last resort, you could create a tempfile with a unique name
(to be sure, not to override any existing data), dump your output there and
later os.unlink() it...
A quick google revealed the answer - there is a device called NUL which
achieves the same purpose.
Thanks
Frank
--
http://mail.python.org/mailman/listinfo/python-list
Re: Question about StringIO
Diez B. Roggisch wrote: Thanks, Steve and Diez, for the replies. I didn't think it was possible, but it was worth asking :-) I will try to explain my experience with popen() briefly. I have some sql scripts to create tables, indexes, procedures, etc. At present there are about 50 scripts, but this number will grow. I have been running them manually so far. Now I want to automate the process. I am supporting PostgreSQL and MS SQL Server, and the syntax is slightly different in some cases. Rather than maintain two sets of scripts, I prefix some lines with -pg- or -ms- to indicate the platform, and then use Python to parse the scripts and generate a correct output for each platform, passing it to 'psql' and 'osql' respectively, using popen(). Why don't youn use te python DB-Api instead? Regards, Diez My scripts are used to create the tables in the database. I didn't think that DB-API covered that. However, even if it did, I don't think it would handle differences such as the following. For Unicode support, PostgreSQL uses the character-set specified when the database is created. SQL Server allows you to specify it for each column, using the datatype NCHAR and NVARCHAR instead of CHAR and VARCHAR. PostgreSQL uses data types called DATE and TIMESTAMP. SQL Server uses DATETIME (it also uses TIMESTAMP, but that is used for something else). Both DBMS's have the concept of a column which is automatically assigned a 'next number' each time a row is created, but the syntax for defining the column is completely different. PostgreSQL allows the use of a WHERE clause when creating an INDEX, which is useful if you only want to index a subset of a table. SQL Server has the concept of a CLUSTERED INDEX, whereby it stores the rows physically in index sequence. It defaults to using a clustered index for the primary key. Often this is not what you want, so it is desirable to specify the primary key as NONCLUSTERED, and then specify a CLUSTERED index for a more frequently used column. These are just a few of the differences, but you get the idea. If there is a better way to do this in a cross-platform manner, I would love to know how. Thanks Frank -- http://mail.python.org/mailman/listinfo/python-list
Re: Let My Terminal Go
On 10 Oct 2005 22:58:08 -0700 [EMAIL PROTECTED] wrote: How do I implement this in my application written in python? Google for python daemonize. -- jk -- http://mail.python.org/mailman/listinfo/python-list
Re: [Info] PEP 308 accepted - new conditional expressions
Op 2005-10-10, Terry Hancock schreef [EMAIL PROTECTED]: On Sunday 09 October 2005 07:50 am, phil hunt wrote: On Fri, 7 Oct 2005 01:05:12 -0500, Terry Hancock [EMAIL PROTECTED] wrote: GvR's syntax has the advantage of making grammatical sense in English (i.e. reading it as written pretty much makes sense). I know, let's re-write Python to make it more like COBOL! That's bound to be a winner! Whereas the natural order of condition affirmative negative is natural for what reason? That it is so in C? I don't find that so compelling either, frankly. Why should it really matter in the end? I've always found C's order (and punctuation) confusing, I have to look it up practically everytime I use it or have to read it (which correlates to it being used very rarely, with causality in both directions). Given that situation, choosing a form which is easy to read is surely an advantage, and, since it is the way that Python has handled logic in the past, it makes sense to continue doing so. Personnaly I would think some consistency between conditional expressions and conditional statements would have been a good thing. I haven't seen a discussion where the following kind of if statement was discussed. do: return a[0] if a[0] a[1] else: return a[1[ No doubt, ANY choice of ternary operator for Python will be criticized, and no doubt, ANY choice would nevertheless be usable. Agreed, I think having it is more important than what form it comes in. My preference has more to do with consistency with the statement. OTOH, I think this choice is consistent with the rest of Python's design. The general choice to use keyword operators for LOGIC and symbolic operators for MATH is retained, and so long as we're describing the logic in words, it makes sense for the wording to sound natural. Consistency certainly does make it easier for me to remember. I think that a consistency within the language would have made more sense than consistency with someone's mother tongue. When I program I program in python or some other programming language. Not in english, dutch, french or some other natural language. But for me this is just style talk. I don't care that much for style, I'm more concerned with functionality and I'm glad this functionality will become available. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
mod_python
Today I was busy to install mod_python.
I have put the line
LoadModule python_module libexec/mod_python.so
into the httpd.conf file.
It Works!
Apache load mod_python /3.2.2.b Python2.4
But my problem is where I have to place te following code in de
httpd.conf?
Directory C:\Program Files\Apache Group\Apache2\htdocs\project\
AddHandler mod_python .py
PythonHandler mptest
PythonDebug On
/Directory
Because al the tutorials write this. But where?
If I try to put the code some where,
apache give the following message by testing the configure:
Multiple Directory arguments not (yet) supported
But what i have to change or replace.
I test with the next file:
C:\Program Files\Apache Group\Apache2\htdocs\project\
mptest.py
from mod_python import apache
def handler(req):
req.content_type = 'text/plain'
req.send_http_header()
req.write('mptest.py\n')
return apache.OK
Is this code enough for testing?
--
http://mail.python.org/mailman/listinfo/python-list
Re: Send password over TCP connection
Paul Rubin wrote: Laszlo Zsolt Nagy [EMAIL PROTECTED] writes: This is a bit offtopic here. I read the RFC and I do not see why SRP is not vulnerable to dictionary attacks. If I have a working client software then I can use it to reveal passwords. Isn't it a dictionary attack? Dictionary attack in this context means an eavesdropper records a session, then compares all the hashed passwords against a word list offline. If the attacker is allowed to make unlimited online queries, then he can guess at SRP passwords too. But the host should notice that and prevent it. I see. So the eavesdropper records the random strings and the password hash value sent. Having these values, he can try to find a suitable password in his list that will result in the same communication. He can do this without having to connect to the server again, just by replaying the algorithm for a given password (and the same 'random' strings). The difference in SRP is that the random strings are private, they will never be sent over the network. So they cannot be eavesdropped. Cracking SRP would require to calculate the dividers of a product of two very big primes (like in RSA). This is why it is hard to use dictionary attacks - you cannot replay the algorithm for a given password. Thank you, I think I understand now. Les -- http://mail.python.org/mailman/listinfo/python-list
Re: mod_python
Python_it wrote:
(...)
But my problem is where I have to place te following code in de
httpd.conf?
Directory C:\Program Files\Apache Group\Apache2\htdocs\project\
AddHandler mod_python .py
PythonHandler mptest
PythonDebug On
/Directory
Because al the tutorials write this. But where?
try put it at the end of your http.conf file.
If I try to put the code some where,
apache give the following message by testing the configure:
Multiple Directory arguments not (yet) supported
But what i have to change or replace.
just an idea, try:
Directory C:\Program Files\Apache Group\Apache2\htdocs\project
...
/Directory
because it sounds like apache parser gets confused
with all those slashes.
I test with the next file:
C:\Program Files\Apache Group\Apache2\htdocs\project\
mptest.py
from mod_python import apache
def handler(req):
req.content_type = 'text/plain'
req.send_http_header()
req.write('mptest.py\n')
return apache.OK
Is this code enough for testing?
i believe so.
also check this:
Getting mod_python Working
http://www.dscpl.com.au/articles/modpython-001.html
--
deelan http://www.deelan.com/
--
http://mail.python.org/mailman/listinfo/python-list
Re: Question about StringIO
Thanks for this pointer. I have read it, but I don't think it applies to my situation, as it talks about 'reading' from the child's stdout while the child is 'writing' to stderr. But that is exactly the point: the psql blocks because you don't read away the buffered data. Start a thread, read that stdout/stderr and see if things go smoothly. Diez -- http://mail.python.org/mailman/listinfo/python-list
SOAPpy, WSDL, non-standard types and my graying hair
Hello, I'm trying to use SOAPpy with WSDL (talking to http://www.seapine.com/ttpro.html). proxy.show_methods for getRecordListForTable is: Method Name: getRecordListForTable In #0: cookie ((u'http://www.w3.org/2001/XMLSchema', u'long')) In #1: tablename ((u'http://www.w3.org/2001/XMLSchema', u'string')) In #2: filtername ((u'http://www.w3.org/2001/XMLSchema', u'string')) In #3: columnlist ((u'urn:testtrack-interface', u'ArrayOfCTableColumn')) Out #0: recordlist ((u'urn:testtrack-interface', u'CRecordListSoap')) I know how to prepare the first three arguments (using SOAPpy.stringType and SOAPpy.longType). I can't find the documentation on how to prepare the last argument. Any ideas? pointers? ... Thanks. -- Miki Tebeka [EMAIL PROTECTED] http://tebeka.bizhat.com The only difference between children and adults is the price of the toys pgpmRrBPnFq5x.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Question about StringIO
My scripts are used to create the tables in the database. I didn't think that DB-API covered that. The DB-Api covers executin arbirary SQL - either DDL or DML. It is surely centered around DML, but that doesn't mean that its not usabel to issue create ... statements. However, even if it did, I don't think it would handle differences such as the following. snip All that has nocthing to do with teh API - you'd still need your differentiated DDL - but the communication with the programs would go away. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: mod_python
Thanks for your replay. I put the handler code at the end of the file. No error! But if I go to my localhost\project\mptest.py The code of my function appears. I solve this by put the following code in the confige file: Directory .. AllowOverride FileInfo /Directory -- http://mail.python.org/mailman/listinfo/python-list
Re: Question about StringIO
Diez B. Roggisch wrote: Thanks for this pointer. I have read it, but I don't think it applies to my situation, as it talks about 'reading' from the child's stdout while the child is 'writing' to stderr. But that is exactly the point: the psql blocks because you don't read away the buffered data. Start a thread, read that stdout/stderr and see if things go smoothly. Diez Of course (kicks himself), it is obvious now that you have explained it. I tried your suggestion and it works perfectly. Many thanks Frank -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for info on Python's memory allocation
Sybren Stuvel wrote: Steven D'Aprano enlightened us with: he says that every time you try to append to a list that is already full, Python doubles the size of the list. This wastes no more than snip If, on the other hand, you double the memory every time you run out, you have to copy much less data, and in the end it turns out you need roughly N steps to add N items to the list. That's a lot better, isn't it? This begs a different question along the same lines. If I have a generator or other iterable producing a vast number of items, and use it like this: s = [k for k in iterable] if I know beforehand how many items iterable would possibly yield, would a construct like this be faster and use less memory? s = [0] * len(iterable) for i in xrange(len(iterable)): s[i] = iterable.next() -- Lasse Vågsæther Karlsen http://usinglvkblog.blogspot.com/ mailto:[EMAIL PROTECTED] PGP KeyID: 0x2A42A1C2 -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python
On Mon, 10 Oct 2005 17:20:35 +, dannypatterso wrote: [snip] I'm a hobby programmer using mostly BASIC(s) and some Java. I know procedural programming and I know what encapsulation, inheritance and polymorphism are but I have very little experience in using them as I've written just a few Java programs (i.e., I guess I could use a primer in OO programming). There was an excellent such primer on devshed, by Icarus, but they appear to have taken it down. I saved a copy of it to my HD. Would there be anything morally, or legally wrong with me uploading it to my site? -- www.wintergreen.in -- http://mail.python.org/mailman/listinfo/python-list
Re: Question about StringIO
Diez B. Roggisch wrote: My scripts are used to create the tables in the database. I didn't think that DB-API covered that. The DB-Api covers executin arbirary SQL - either DDL or DML. It is surely centered around DML, but that doesn't mean that its not usabel to issue create ... statements. However, even if it did, I don't think it would handle differences such as the following. snip All that has nocthing to do with teh API - you'd still need your differentiated DDL - but the communication with the programs would go away. Diez I understand. It certainly gives me an alternative approach - I will experiment to see which suits my purpose best. Many thanks for your assistance. Frank -- http://mail.python.org/mailman/listinfo/python-list
A faster shutil.rmtree or maybe a command.
H! Sometimes I must delete 2 very big directory's. The directory's have a very large tree with much small file's in it. So I use shutil.rmtree() But its to slow. Is there a faster method ? I use FreeBsd 5.4. --- is it maybe faster to walking in the directy en delete each file? Thanks, GC-Martijn -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python
Chris Dewin [EMAIL PROTECTED] writes: There was an excellent such primer on devshed, by Icarus, but they appear to have taken it down. I saved a copy of it to my HD. Would there be anything morally, or legally wrong with me uploading it to my site? A little googling shows it's still up at: http://www.melonfire.com/community/columns/trog/print.php?id=94 part 1 http://www.melonfire.com/community/columns/trog/print.php?id=96 part 2 -- http://mail.python.org/mailman/listinfo/python-list
Re: A faster shutil.rmtree or maybe a command.
[EMAIL PROTECTED] wrote: Sometimes I must delete 2 very big directory's. The directory's have a very large tree with much small file's in it. So I use shutil.rmtree() But its to slow. Is there a faster method ? Is os.system(rm -rf %s % directory_name) much faster? -- Giovanni Bajo -- http://mail.python.org/mailman/listinfo/python-list
A problem while using urllib
Hi, I was using urllib to grab urls from web. here is the work flow of my program: 1. Get base url and max number of urls from user 2. Call filter to validate the base url 3. Read the source of the base url and grab all the urls from href property of a tag 4. Call filter to validate every url grabbed 5. Continue 3-4 until the number of url grabbed gets the limit In filter there is a method like this: -- # check whether the url can be connected def filteredByConnection(self, url): assert url try: webPage = urllib2.urlopen(url) except urllib2.URLError: self.logGenerator.log(Error: + url + urlopen error timed out) return False except urllib2.HTTPError: self.logGenerator.log(Error: + url + not found) return False self.logGenerator.log(Connecting + url + successed) webPage.close() return True But every time when I ran to the 70 to 75 urls (that means 70-75 urls have been tested via this way), the program will crash and all the urls left will raise urllib2.URLError until the program exits. I tried many ways to work it out, using urllib, set a sleep(1) in the filter (I thought it was the massive urls crashed the program). But none works. BTW, if I set the url from which the program crashed to base url, the program will still crashed at the 70-75 url. How can I solve this problem? thanks for your help Regards, Johnny -- http://mail.python.org/mailman/listinfo/python-list
Idle bytecode query on apparently unreachable returns
What puzzles me, though, are bytecodes 17, 39 and 42 - surely these aren't reachable? Does the compiler just throw in a default 'return None' epilogue, with routes there from every code path, even when it's not needed? If so, why? Hi. pyc (http://freshmeat.net/projects/pyc) can already remove that unused code since June. As for why, I guess that there is a lot of room for optimizing the bytecode but it's a PITA doing all of it in the current internal compiler. And so developers simply don't care about it. Maybe the ast-branch would make it easier to start generating optimal bytecode. On the other hand, the 'compiler module' produces bad bytecode (for example it miscalculates the 'stacksize' of functions and as a result the generated functions are slow), it doesn't use LIST_APPEND, and it doesn't even do the simple peephole optimizations of the intenal compiler! In the latest version 0.8 to-be-released, pyc does many more bytecode optimizations that give a +5% to pystone and it can also bring generator expressions and decorators to python 2.3. [OT] 0.8 is stuck on the conditional. We can bring the conditional expression from the __future__ to users of 2.3/2.4 but I'm not sure people really like the T if C else F syntax over C ? T : F. The argument: python uses 'and'/'or' instead of /|| and therefore it should also use 'if-else' instead of '?:', just doesn't apply. And generally this is one of those things that you will never find the argument that proves which is the right choice. In these cases you do what you *LIKE* more. Perhaps a vote would be in order considering the this-or-that nature of the conditional expression :) st. This message was sent through the TEI of ATHENS by means of NOC. -- http://mail.python.org/mailman/listinfo/python-list
Re: Batteries Included?
On 11 Oct 2005 00:10:01 -0700 Paul Rubin wrote: Personally I think including a .exe packager in Python would be a great idea. As a Linux user I can't easily run Windows-specific utilities like Inno Setup. So I don't have a good way to make .exe's from my Python code that Windows users can easily run. Having a cross platform .exe packager included with Python would be useful the same way cross compilers are useful. I'm using an x86 computer but I can easily configure gcc to produce ARM code. Why shouldn't my Linux Python installation be able to produce Windows .exe's? Because you can't run it yourself? If you cannot run the freshly-made exe yourself, why would you want to distrubute it, without even trying? But if you can, then you can run the InnoSetup as well. But, for me, I don't care whether such an option will be included or not. I won't object anyway. -- jk -- http://mail.python.org/mailman/listinfo/python-list
Re: A faster shutil.rmtree or maybe a command.
A little. I think its yust to big to handle it. I'm going to ask it in a freebsd forum, maybe they know how to speed up. Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: mod_python
deelan wrote:
Python_it wrote:
(...)
But my problem is where I have to place te following code in de
httpd.conf?
Directory C:\Program Files\Apache Group\Apache2\htdocs\project\
AddHandler mod_python .py
PythonHandler mptest
PythonDebug On
/Directory
Because al the tutorials write this. But where?
try put it at the end of your http.conf file.
If I try to put the code some where,
apache give the following message by testing the configure:
Multiple Directory arguments not (yet) supported
But what i have to change or replace.
just an idea, try:
Directory C:\Program Files\Apache Group\Apache2\htdocs\project
...
/Directory
because it sounds like apache parser gets confused
with all those slashes.
I could be wrong, but i think i read something about apache expecting
you to use forward slashes instead of backslashes when i was using
windows...
I seem to recall it being in the readme. ...?
I test with the next file:
C:\Program Files\Apache Group\Apache2\htdocs\project\
mptest.py
from mod_python import apache
def handler(req):
req.content_type = 'text/plain'
req.send_http_header()
req.write('mptest.py\n')
return apache.OK
Is this code enough for testing?
i believe so.
also check this:
Getting mod_python Working
http://www.dscpl.com.au/articles/modpython-001.html
HTH,
Peter
--
http://mail.python.org/mailman/listinfo/python-list
strange import error with Python-2.4.1
Whilst testing the excellent xlrd http://www.python.org/pypi/xlrd/0.3a1 I came across the following strangeness when trying to add an import of os to assist with debugging/tracing. At line 66 I replaced import sys with import sys, os and then ran python runxlrd.py --help and got this error which is not a real syntax problem Traceback (most recent call last): File runxlrd.py, line 5, in ? import xlrd File C:\python24\lib\site-packages\xlrd\__init__.py, line 552 if DEBUG: print self.logfile, SST Processing if I remove the , os then the run produces the expected usage: runxlrd.py [options] command input-file-patterns options: -h, --helpshow this help message and exit -l LOGFILENAME, --logfilename=LOGFILENAME contains error messages -v VERBOSITY, --verbosity=VERBOSITY level of information and diagnostics provided I also am able to change the line to import sys import os without error. This behaviour doesn't occur with 2.4.2 or 2.4 only with 2.4.1. I looked for some bug fix in the recently released 2.4.2 that related, but couldn't find anything obvious. My system doesn't have psyco so xlrd's attempted psyco use shouldn't be an issue. Thanks for 2.4.2, but is this one of the fixed bugs or has it just got harder to induce? -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for info on Python's memory allocation
Lasse Vågsæther Karlsen wrote: If I have a generator or other iterable producing a vast number of items, and use it like this: s = [k for k in iterable] if I know beforehand how many items iterable would possibly yield, would a construct like this be faster and use less memory? s = [0] * len(iterable) for i in xrange(len(iterable)): s[i] = iterable.next() You can easily answer the speed aspect of your question using the timeit module: ~ $ python2.4 -m timeit -s'iterable=range(1000)' '[k for k in iterable]' 1 loops, best of 3: 111 usec per loop ~ $ python2.4 -m timeit -s'iterable=range(1000)' 's = [0]*len(iterable); it = iter(iterable)' 'for i in xrange(len(iterable)): s[i] = it.next()' 1000 loops, best of 3: 513 usec per loop ~ $ python2.4 -m timeit -s'iterable=range(1000)' 's = [0]*len(iterable)' 'for i, v in enumerate(iterable): s[i] = v' 1000 loops, best of 3: 269 usec per loop ~ $ python2.4 -m timeit -s'iterable=range(1000)' 'list(iterable)' 10 loops, best of 3: 7.33 usec per loop Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Batteries Included?
[EMAIL PROTECTED] writes: Because you can't run it yourself? If you cannot run the freshly-made exe yourself, why would you want to distrubute it, without even trying? But if you can, then you can run the InnoSetup as well. Obviously I'd want someone to test the .exe before putting it in wide distribution. That doesn't solve the problem of how to make the .exe. -- http://mail.python.org/mailman/listinfo/python-list
Re: Let My Terminal Go
Hello, Thank you. That's all I needed. For some reason, I had always assumed forking was an expensive process. I guess I was ill-informed. -- http://mail.python.org/mailman/listinfo/python-list
Re: Let My Terminal Go
Hello, Thanks to all the responders and helpers on the group. I'm learning everyday. Thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: strange import error with Python-2.4.1
Robin Becker wrote: Whilst testing the excellent xlrd http://www.python.org/pypi/xlrd/0.3a1 I came across the following strangeness when trying to add an import of os to assist with debugging/tracing. At line 66 I replaced import sys with import sys, os and then ran python runxlrd.py --help and got this error which is not a real syntax problem Traceback (most recent call last): File runxlrd.py, line 5, in ? import xlrd File C:\python24\lib\site-packages\xlrd\__init__.py, line 552 if DEBUG: print self.logfile, SST Processing if I remove the , os then the run produces the expected usage: runxlrd.py [options] command input-file-patterns options: -h, --helpshow this help message and exit -l LOGFILENAME, --logfilename=LOGFILENAME contains error messages -v VERBOSITY, --verbosity=VERBOSITY level of information and diagnostics provided I also am able to change the line to import sys import os without error. This behaviour doesn't occur with 2.4.2 or 2.4 only with 2.4.1. I looked for some bug fix in the recently released 2.4.2 that related, but couldn't find anything obvious. My system doesn't have psyco so xlrd's attempted psyco use shouldn't be an issue. Thanks for 2.4.2, but is this one of the fixed bugs or has it just got harder to induce? Robin: Can I ask if you are specifying a source encoding in your file with a pragma (?) like # -*- coding: iso-8859-15 -*- I've noticed what appear to be spurious syntax errors from time to time on such files, and have been attempting to debug the problem for some time without any apparent success. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: strange import error with Python-2.4.1
Steve Holden wrote: Can I ask if you are specifying a source encoding in your file with a pragma (?) like # -*- coding: iso-8859-15 -*- I've noticed what appear to be spurious syntax errors from time to time on such files, and have been attempting to debug the problem for some time without any apparent success. http://www.python.org/sf/1175396 /F -- http://mail.python.org/mailman/listinfo/python-list
Re: strange import error with Python-2.4.1
Robin Becker [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] This behaviour doesn't occur with 2.4.2 or 2.4 only with 2.4.1. I looked for some bug fix in the recently released 2.4.2 that related, but couldn't find anything obvious. One of the various codecs fixes, I think. Bug #1175396, perhaps. -- http://mail.python.org/mailman/listinfo/python-list
Re: Idle bytecode query on apparently unreachable returns
[Tom Anderson]: What puzzles me, though, are bytecodes 17, 39 and 42 - surely these aren't reachable? Does the compiler just throw in a default 'return None' epilogue, with routes there from every code path, even when it's not needed? If so, why? Since unreachable code is never executed, there is no performance payoff for optimizing it away. It is not hard to write a dead-code elimination routine, but why bother? It would save a few bytes, slow down compilation time, save nothing at runtime, and make the compiler more complex/fragile. FWIW, the peephole optimizer in Python/compile.c is mature -- the low hanging fruit has already been harvested, leaving the field of remaining optimizations somewhat barren. Raymond -- http://mail.python.org/mailman/listinfo/python-list
Re: Python's Performance
Steve Holden wrote: And we definitely need agile in there. Bugger, I'll go out and come in again ... Used in the same breath as the word bugger, I'm not sure the phrase go out and come in again is entirely appropriate for a family forum. ;-) But I'm also not sure I ought to post that to the group, so I'll spare them and just inflict the thought on you! Cheers, -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Merging sorted lists/iterators/generators into one stream of values...
snip Another idea for this method would be that in some cases I noticed that it was useful to know which source each element would come from as well, as well as removing duplicates from the results. For instance s1 = [1, 3, 5, 7] s2 = [2, 3, 4] for k, s in merge_by_sort(s1, s2): print k, from source, s this would print: 1 from source 0 2 from source 1 3 from source 1 3 from source 0 4 from source 1 5 from source 0 7 from source 0 and the above list has 3 twice, so possibly: 1 from sources [0] 2 from sources [1] 3 from sources [0, 1] 4 from sources [1] 5 from sources [0] 7 from sources [0] This latter one would be a slightly more heavy method as it would have to compare the N first elements of the list or heap to figure out what indices to yield as well. However, the previous solution could be: def merge_by_sort(*sources, **options): if cmp in options: comparison = options[cmp] else: comparison = cmp iterables = [] for index, source in enumerate(sources): try: source = iter(source) iterables.append([source.next(), index, source]) except StopIteration: pass iterables.sort(cmp=comparison, key=lambda x: x[0], reverse=True) while iterables: yield iterables[-1][0], iterables[-1][1] try: iterables[-1][0] = iterables[-1][2].next() if len(iterables) 1 and comparison(iterables[-1][0], iterables[-2][0]) 0: iterables.sort(comparison, key=lambda x: x[0], reverse=True) except StopIteration: iterables.pop(-1) -- Lasse Vågsæther Karlsen http://usinglvkblog.blogspot.com/ mailto:[EMAIL PROTECTED] PGP KeyID: 0x2A42A1C2 -- http://mail.python.org/mailman/listinfo/python-list
Re: Send password over TCP connection
Laszlo Zsolt Nagy wrote: Peter Hansen wrote: Ignoring all the other issues, any solution which actually requires the password to be stored on the server is a bad solution. Administrators should not have access to user passwords, and in addition users should not be put in the position of having to trust your server-side security to keep their passwords (which they might have used on other systems) from being grabbed by hackers. Users will always need to trust in the server. The authentication process ensures that the client is really talking with the desired server and vice versa. But even if you know that you are talking to the right server, you need to trust in the server. The administrator of the server has access to all data. Possibly other persons and softwares too. Passwords are not different from this point of view. If you're saying that people have no choice but to trust that their passwords, stored in the clear on the server of some idiot who didn't know better, are safe from casual administrator observation and safe from hackers stealing the password file, then you shouldn't be allowed anywhere near a supposedly secure system... If you're just saying that one has to trust that the server you are talking to at this instant in time is really the one you thought it was, then that's an entirely different issue and I agree. But storing passwords in the clear, thus allowing administrators full access to users' passwords, is absolutely *not* necessary. That's my point, regardless of what other issues this thread spawns. If the OP implements strictly the sequence he mentioned in the posting to which I was replying, he'll be the aforementioned idiot... -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Python's Performance
Peter Hansen wrote: But I'm also not sure I ought to post that to the group, so I'll spare them and just inflict the thought on you! Or, maybe I'll just fail to trim the newsgroup line and accidentally post to the group anyway. Yes, that's just what I'll do. Sorry folks. :-) -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: strange import error with Python-2.4.1
Fredrik Lundh wrote: Steve Holden wrote: Can I ask if you are specifying a source encoding in your file with a pragma (?) like # -*- coding: iso-8859-15 -*- I've noticed what appear to be spurious syntax errors from time to time on such files, and have been attempting to debug the problem for some time without any apparent success. http://www.python.org/sf/1175396 Thanks! regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: subprocess and non-blocking IO (again)
Marc Carter [EMAIL PROTECTED] wrote:
import subprocess,select,sys
speakers=[]
lProc=[]
for machine in ['box1','box2','box3']:
p = subprocess.Popen( ('echo '+machine+';sleep 2;echo goodbye;sleep
2;echo cruel;sleep 2;echo world'), stdout=subprocess.PIPE,
stderr=subprocess.STDOUT, stdin=None, universal_newlines=True )
lProc.append( p )
speakers.append( p.stdout )
while speakers:
speaking = select.select( speakers, [], [], 1000 )[0]
for speaker in speaking:
speech = speaker.readlines()
if speech:
for sentence in speech:
print sentence.rstrip('\n')
sys.stdout.flush() # sanity check
else: # EOF
speakers.remove( speaker )
- SNIP -
The problem with the above is that the subprocess buffers all its output
when used like this and, hence, this automation is not informing me of
much :)
The problem with the above is that you are calling speaker.readlines()
which waits for all the output.
If you replace that with speaker.readline() or speaker.read(1) you'll
see that subprocess hasn't given you a buffered pipe after all!
In fact you'll get partial reads of each line - you'll have to wait
for a newline before processing the result, eg
import subprocess,select,sys
speakers=[]
lProc=[]
for machine in ['box1','box2','box3']:
p = subprocess.Popen( ('echo '+machine+';sleep 2;echo goodbye;sleep 2;echo
cruel;sleep 2;echo world'), stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
stdin=None, universal_newlines=True, shell=True)
lProc.append( p )
speakers.append( p.stdout )
while speakers:
speaking = select.select( speakers, [], [], 1000 )[0]
for speaker in speaking:
speech = speaker.readline()
if speech:
for sentence in speech:
print sentence.rstrip('\n')
sys.stdout.flush() # sanity check
else: # EOF
speakers.remove( speaker )
gives
b
o
x
1
b
o
x
3
b
o
x
2
pause...
g
o
o
d
b
y
e
etc...
I'm not sure why readline only returns 1 character - the pipe returned
by subprocess really does seem to be only 1 character deep which seems
a little inefficient! Changing bufsize to the Popen call doesn't seem
to affect it.
--
Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick
--
http://mail.python.org/mailman/listinfo/python-list
Re: subprocess and non-blocking IO (again)
Donn Cave wrote: If you want to use select(), don't use the fileobject functions. Use os.read() to read data from the pipe's file descriptor (p.stdout.fileno().) This is how you avoid the buffering. Thankyou, this works perfectly. I figured it would be something simple. Marc -- http://mail.python.org/mailman/listinfo/python-list
How to do *args, **kwargs properly
I must be missing something but what is the proper way to do a function using such arguments ? Specifically I'm looking for: - ability to take an unspecified number of positional arguments - ability to take optional named arguments that follows the first arguments - raise appropriate errors if I use the wrong named arguments for instance: fn(1, 2, 3) fn(1, 2, 3, cmp=lambda x, y: y-x) fn(1, 2, 3, cpm=lambda x, y: y-x) # TypeError on this Is the following the way to go ? def fn(*values, **options): comparison = cmp for key, value in options.iteritems(): if key == cmp: comparison = value else: raise TypeError, '%s' is an invalid keyword argument for this function % key # rest of function here or is the proper python way simply this: def fn(*values, **options): if cmp in options: comparison = options[cmp] else: comparison = cmp # rest of function here and thus ignoring the wrong parameter names? -- Lasse Vågsæther Karlsen http://usinglvkblog.blogspot.com/ mailto:[EMAIL PROTECTED] PGP KeyID: 0x2A42A1C2 -- http://mail.python.org/mailman/listinfo/python-list
Re: A problem while using urllib
Johnny Lee [EMAIL PROTECTED] wrote: ... try: webPage = urllib2.urlopen(url) except urllib2.URLError: ... webPage.close() return True But every time when I ran to the 70 to 75 urls (that means 70-75 urls have been tested via this way), the program will crash and all the urls left will raise urllib2.URLError until the program exits. I tried many ways to work it out, using urllib, set a sleep(1) in the filter (I thought it was the massive urls crashed the program). But none works. BTW, if I set the url from which the program crashed to base url, the program will still crashed at the 70-75 url. How can I solve this problem? thanks for your help Sure looks like a resource leak somewhere (probably leaving a file open until your program hits some wall of maximum simultaneously open files), but I can't reproduce it here (MacOSX, tried both Python 2.3.5 and 2.4.1). What version of Python are you using, and on what platform? Maybe a simple Python upgrade might fix your problem... Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: How to do *args, **kwargs properly
Lasse Vågsæther Karlsen [EMAIL PROTECTED] writes:
or is the proper python way simply this:
def fn(*values, **options):
if cmp in options: comparison = options[cmp]
else: comparison = cmp
# rest of function here
and thus ignoring the wrong parameter names?
I don't know about proper but it's pretty common. You could also
use a positional arg:
def fn(cmp, *values):
# blah blah
fn(cmp, 1, 2, 3) # call the function
You could check for invalid keys a little more concisely than in your
example. For example with sets:
def fn(*values, **options):
if Set(options.keys()) - Set(('cmp')):
raise error...
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Re: How to do *args, **kwargs properly
Lasse Vågsæther Karlsen [EMAIL PROTECTED] wrote:
...
fn(1, 2, 3)
fn(1, 2, 3, cmp=lambda x, y: y-x)
fn(1, 2, 3, cpm=lambda x, y: y-x) # TypeError on this
I assume these are your specs.
or is the proper python way simply this:
def fn(*values, **options):
if cmp in options: comparison = options[cmp]
else: comparison = cmp
# rest of function here
and thus ignoring the wrong parameter names?
Errors should not pass silently, unless explicitly silenced.
So, I would code:
def fn(*values, **opts):
cmp = opts.pop('cmp', cmp)
if opts: raise ValueError, 'Unknown option(s): %s' % opts.keys()
# rest of function here
There are some cases where ignoring extra options, or just warning about
them, may be more appropriate, but normally I would check...
Alex
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Re: Wanted: Python module allowing direct access to raw sectors ofharddrives (MFT, boot sector, etc.) in MS Windows
Thank you for your reply, even if currently not
that interesting for me because after the first
CD writer for IDE were available I stopped to
use SCSI and didn't come back to it since then.
Does the Python open() command not work the
same way for SCSI drives as for IDE or USB
drives (I can't try it myself, because of above)?
Claudio
P.S. for those who are interested I have uploaded a
Python script I wrote for myself to have a reference to
this subject to:
http://people.freenet.de/AiTI-IT/Python/HowTo_AccessRawSectorsOfPhysicalDrives.py
:-)
sam [EMAIL PROTECTED] schrieb im Newsbeitrag
news:[EMAIL PROTECTED]
The following site contains my routines to access information from the
Microsoft SCSIPASSTHROUGH layer under windows. These routines allow you
to access the storage devices mounted under windows using SCSI
commands. The dll that I provide will work with Python 2.3
http://starship.python.net/crew/samschul/
Sam Schulenburg
Claudio Grondi wrote:
Thank you Jeff very much for your quick reply.
It saved me really much time of digging in the wrong direction.
[EMAIL PROTECTED] wrote in
news:[EMAIL PROTECTED]...
I took the advice from this web page:
http://support.microsoft.com/kb/q100027/
Ok, I had found this page myself during Googling, but I have missed just
to try to use the described way of addressing physical devices with file
opening in Python.
It works as expected with harddrives so you are right that you are
getting
the MBR with the proposed code.
After some not always happy end adventures with Python
scripting I am impressed by the power of the concept behind
the language once again.
Claudio
(I don't know how this extends to floppies, and the 9x family of OSes
isn't
listed in applies to, so this may not help your case)
Here, I open physical drive 0 and see that the magic number
indicates a
valid
boot record. I believe it is the MBR.
f = open('.\\PhysicalDrive0', 'rb')
f.read(512)[-2:]
'U\xaa' # that is, hex 55 AA
I don't know much about low-level filesystem or partition details--I
got
the
tidbit about the 55 AA magic number from
http://www-uxsup.csx.cam.ac.uk/pub/doc/suse/sles9/adminguide-sles9/ch08.ht
ml
Jeff
[EMAIL PROTECTED] schrieb im Newsbeitrag
news:[EMAIL PROTECTED]
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Re: Let My Terminal Go
Mike Meyer wrote: The easy way to do all these things - from C, anyway - is with daemon(3). That isn't wrapped as part of the Python library. The easiest way to solve your problem may be write a wrapper for that call. If daemon exists on enough systems, submitting your wrapper as a patch to the os modulee would be appropriate. I think the deamon() library call only exists on the BSDs. Anyway, there it is implemented with a fork() call and some additional code to close std descriptors, so there's no practical difference between calling deamon() and fork() by yourself... -- http://mail.python.org/mailman/listinfo/python-list
XMS .NET: IBM Message Service Client for .NET Beta
IronPython and Boo developers may find this interesting: The second refresh of the IBM Message Service Client for .NET Beta is now available: http://www14.software.ibm.com/webapp/download/search.jsp?go=yrs=message The key enhancements in this refresh are: - The supported messaging environments have been extended to include IBM WebSphere MQ 5.3 and 6 (for point to point messaging only) and WBI Message Broker 6. - Several updates have been made to remove API restrictions and fix minor defects reported since the previous refresh or during continued testing. - The first full draft of the user documentation has been completed. Further details can be found in the products readme.txt. Any feedback or queries are welcomed at: news://news.software.ibm.com/ibm.software.websphere.mq.beta. But please prefix your XMS-related posts to this Beta newsgroup with 'XMS .NET:'. About XMS .NET: XMS .NET can connect to WebSphere MQ, The default messaging provider in WebSphere Application Server v6 and WebSphere Business Integration Event/Message Brokers. An XMS application can exchange messages with any of the following types of application - An XMS application, a WebSphere MQ JMS application, a native WebSphere MQ application and a JMS application that is using the WebSphere default messaging provider. XMS applications may use different IBM messaging servers with little or no change. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to do *args, **kwargs properly
Lasse Vågsæther Karlsen wrote:
I must be missing something but what is the proper way to do a function
using such arguments ?
- ability to take an unspecified number of positional arguments
You should probably pass a sequence to the method instead. You can do it
the other way, but it's poor coding style in most cases.
- ability to take optional named arguments that follows the first arguments
Setting the default value to a value that cannot exist as an argument is
the normal way. Eg. None.
def fn(vals, cmp=None)
- raise appropriate errors if I use the wrong named arguments
def fn(*values, cmp=None):
if cmp is None:
raise TypeError, '%s' is an invalid keyword argument for this
function % key
If you insist on doing it the other way:
FN_LEGAL_ARGS = set( ('cmp',) )
def fn(*values, **options):
for key in options.keys():
if not key in FN_LEGAL_ARGS:
raise TypeError, '%s' is an invalid keyword argument for
this function % key
--
hilsen/regards Max M, Denmark
http://www.mxm.dk/
IT's Mad Science
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datetime and daylight savings problem
I need to import a bunch of data into our database for which there's a single entry each day which occurs at the same time every day in local time - so I need to convert this to UTC taking into account local daylight savings. However daylight savings just don't seem to be working at all... Python 2.3.5 (#2, May 4 2005, 08:51:39) [GCC 3.3.5 (Debian 1:3.3.5-12)] on linux2 Type help, copyright, credits or license for more information. from pytz import timezone from datetime import datetime t=timezone(Europe/Paris) utc=timezone(UTC) d=datetime(2005,01,24,16,59,tzinfo=t) d datetime.datetime(2005, 1, 24, 16, 59, tzinfo=DstTzInfo 'Europe/Paris' WET0:00:00 STD) d.astimezone(utc) datetime.datetime(2005, 1, 24, 16, 59, tzinfo=StaticTzInfo 'UTC') d2=datetime(2005,06,01,16,59,tzinfo=t) d2 datetime.datetime(2005, 6, 1, 16, 59, tzinfo=DstTzInfo 'Europe/Paris' WET0:00:00 STD) d2.astimezone(utc) datetime.datetime(2005, 6, 1, 16, 59, tzinfo=StaticTzInfo 'UTC') One of these should be in DST, the other shouldn't, I'm not sure why. Additional oddness here d.astimezone(utc).astimezone(t) datetime.datetime(2005, 1, 24, 18, 59, tzinfo=DstTzInfo 'Europe/Paris' CEST+2:00:00 DST) d2.astimezone(utc).astimezone(t) datetime.datetime(2005, 6, 1, 17, 59, tzinfo=DstTzInfo 'Europe/Paris' CET+1:00:00 STD) I'm not sure if it's just something I'm doing completely wrong here... James -- http://mail.python.org/mailman/listinfo/python-list
Re: How to do *args, **kwargs properly
Max M wrote: Lasse Vågsæther Karlsen wrote: I must be missing something but what is the proper way to do a function using such arguments ? - ability to take an unspecified number of positional arguments You should probably pass a sequence to the method instead. You can do it the other way, but it's poor coding style in most cases. So what you're saying is that instead of: def fn(*values, **options): I should use: def fn(values, cmp=cmp): in this specific case? and then instead of: fn(1, 2, 3, cmp=...) this: fn([1, 2, 3], cmp=...) snip I think I'll re-write to use a list instead. -- Lasse Vågsæther Karlsen http://usinglvkblog.blogspot.com/ mailto:[EMAIL PROTECTED] PGP KeyID: 0x2A42A1C2 -- http://mail.python.org/mailman/listinfo/python-list
Re: Comparing lists
Christian Stapfer wrote: Steve Holden [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Christian Stapfer wrote: George Sakkis [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Christian Stapfer [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: try to use set. A reasonable suggestion. A set must have the trade-offs involved. The abstraction itself brings to mind the issues, and the performance can, at least in theory, be handled there. If that is true (that the set abstraction sees the problem), then you can rely on the Python implementation of set to either now, or eventually, have a good implementation -- one not too far off efficient. The Python gang is good at this stuff; a better set implementation will win if it can show better performance without related down-sides. As to the either now, or eventually; if you _must_ have performance now, not in some abstract future, then it behooves you to _test_, _test_, _test_! If the documentation stated the order-of-magnitude behavior of those basic operations up front, then I (and *anyone* else who ever wanted to use those operations on large lists / large sets) could do a quick order-of-magnitude estimation of how a certain program design will behave, performance wise. And, if the proper documentation is in place, and it says dictionary lookup is O(N) (and you avoid using it for exactly that reason), how surprised will you be to discover that the O(N) is only reached if the hash values of the keys are all equal? Oh, maybe you expect O(N) to really mean \Theta(N). Then, if you are a dweeb like me, you will respond that This is not possible, a dictionary of size N must take at least 'O(lg N)' to read the key, never mind processing it. But, it turns out, that given a bound on the size of a process, processing an address is O(1), not O(lg N). Is that too practical for you, or not enough? *Experimenting* is not necessarily as easy to do as you seem to believe. How do you, for example, hit upon the worst-case behavior with your test data? Are you saying the documentation should characterize the cases that achieve worst-case behavior? This is a stiff burden indeed, not one I am used to in even the most rigorous classes I've seen. If there is such a characterization, how burned will you feel if a case is overlooked and that case is the one that you sold to your customer? Are you willing to provide the same guaranteed performance and documentation of performance to your customer that you you expect of the Python system? Would you mind if the quality is proportional to the price you paid? You are, of course, either assuming that there's a single implementation of Python, Of course not! or that all implementations have the same behaviour. Of course not! But it is reasonable, anyway, to ask for information about a specific implementation (that one is *forced* to use). You are not _forced_ to use any implementation of Python. You are free to implement your own Python system. And if the implementer wants to complain that giving such information would break his wonderful abstraction then I can only answer: It is *reality* that *will* break your abstraction as regards performance! It is, therefore, absolutely *no* use to *pretend* you *can* avoid this form of breaking the abstraction by simply avoiding to mention it in the documentation... I simply repeat: I have never seen a paper characterizing the performance of an algorithm as O(expr(N)) that described in details _all_ cases that reached that limit. At most such papers describe _one_ such cases. Nor have I ever seen papers describing the performance of an algorithm as \Theta(expr(N)) that characterized the cases that broke the \Theta performance. If you provide me the papers, provide me a C compiler with equivalent docs on all C expressions, and provide me the funding to update the Python docs, I will be happy to do so for a single version of Python and a since version of CPython. I expect I will have an easier time of it than the IronPython people will have. I consider it the job of the implementer to know about the trade-offs that he has been making in choosing one particular implementation, and to know what computational complexity therefore attaches to the various operations exposed in its interface. Am I to take it you provide this to all of your customers? How reasonable is it to ask me, or anyone else for that matter, to extract, experiment-wise (if it can be done at all with reasonable effort) information that properly belongs to the implementer and really should have been exposed in the documentation in the first place? Not at all reasonable. How reasonable is it to ask me to provide you support information for free? --Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Send password over TCP connection
then, what you proppose? -- http://mail.python.org/mailman/listinfo/python-list
Python Doc Problem Example: sort() (reprise)
Python Doc Problem Example: sort() Xah Lee, 200503 Exhibit: Incompletion Imprecision Python doc “3.6.4 Mutable Sequence Types” at http://python.org/doc/2.4/lib/typesseq-mutable.html in which contains the documentation of the “sort” method of a list. Quote: « Operation Result Notes s.sort([cmp[, key[, reverse]]]) sort the items of s in place(7), (8), (9), (10) (7) The sort() and reverse() methods modify the list in place for economy of space when sorting or reversing a large list. To remind you that they operate by side effect, they don't return the sorted or reversed list. (8) The sort() method takes optional arguments for controlling the comparisons. cmp specifies a custom comparison function of two arguments (list items) which should return a negative, zero or positive number depending on whether the first argument is considered smaller than, equal to, or larger than the second argument: cmp=lambda x,y: cmp(x.lower(), y.lower()) key specifies a function of one argument that is used to extract a comparison key from each list element: cmp=str.lower reverse is a boolean value. If set to True, then the list elements are sorted as if each comparison were reversed. In general, the key and reverse conversion processes are much faster than specifying an equivalent cmp function. This is because cmp is called multiple times for each list element while key and reverse touch each element only once. Changed in version 2.3: Support for None as an equivalent to omitting cmp was added. Changed in version 2.4: Support for key and reverse was added. (9) Starting with Python 2.3, the sort() method is guaranteed to be stable. A sort is stable if it guarantees not to change the relative order of elements that compare equal -- this is helpful for sorting in multiple passes (for example, sort by department, then by salary grade). (10) While a list is being sorted, the effect of attempting to mutate, or even inspect, the list is undefined. The C implementation of Python 2.3 and newer makes the list appear empty for the duration, and raises ValueError if it can detect that the list has been mutated during a sort. » As a piece of documentation, this is a lousy one. The question Python doc writers need to ask when evaluating this piece of doc are these: • can a experienced programer who is expert at several languages but new to Python, and also have read the official Python tutorial, can he, read this doc, and know exactly how to use sort with all the options? • can this piece of documentation be rewritten fairly easily, so that the answer to the previous question is a resounding yes? To me, the answers to the above questions are No and Yes. Here are some issues with the doc: • In the paragraph about the “key” parameter, the illustration given is: “cmp=str.lower”. It should be be “key=str.lower” • This doc lacks examples. One or two examples will help a lot, especially to less experienced programers. (which comprises the majority of readers) In particular, it should give a full example of using the comparison function and one with the “key” parameter. Examples are particularly needed here because these parameteres are functions, often with the “lambda” construct. These are unusual and advanced constructs among imperative programers. • This doc fails to mention what happens when the predicate and the shortcut version conflicts. e.g. “myList.sort(cmp=lambda x,y: cmp(x[0], y[0]), key=lambda x: str(x[1]) )” • The syntax notation Python doc have adopted for indicating optional parameters, does not give a clear view just exactly what combination of optional parameters can be omitted. The notation: “s.sort([cmp[, key[, reverse]]])” gives the impression that only trailing arguments can be omitted, which is not true. • The doc gives no indication of how to omit a optional arg. Should it be “nul”, “Null”, 0, or left empty? Since it doesn't give any examples, doc reader who isn't Python experts is left to guess at how true/false values are presented in Python. • On the whole, the way this doc is written does not give a clear picture of the roles of the supplied options, nor how to use them. Suggested Quick Remedy: add a example of using the cmp function. And a example using the “key” function. Add a example of Using one of them and with reverse. (the examples need not to come with much explanations. One sentence annotation is better than none.) Other than that, the way the doc is layed out with a terse table and run-on footnotes (employed in several places in Python doc) is not inductive. For a better improvement, there needs to be a overhaul of the organization and the attitude of the entire doc. The organization needs to be programing based, as opposed to implementation or computer science based. (in this regard, one can learn from the Perl folks). As to attitude, the writing needs to be Python-as-is, as opposed to computer science framework, as
Where is the error
hello,
when i run the following code to Read and tokenize data from a tagged text as follows :
from nltk.corpus import brownfrom nltk.tagger import TaggedTokenizerfrom nltk.tokenizer import *tagged_txt_str=open('corpus.txt' ).read()tagged_txt_token=Token(TEXT=tagged_txt_str)TaggedTokenizer.tokenize(tagged_txt_token)print tagged_txt_token
i got the following error :Traceback (most recent call last):File "C:\My Documents\TAGGING.PY", line 3, in -toplevel-from nltk.tagger import TaggedTokenizerImportError: cannot import name TaggedTokenizer
could anyone help me thanks in advanceenas
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Re: Function decorator that caches function results
Paul Rubin http://[EMAIL PROTECTED] (PR) wrote: PR Tom Anderson [EMAIL PROTECTED] writes: PR That's misleading, I'd say a closure is a combination of a function PR (executable code) and a lexical environment [snip] PR This is all described in SICP (mitpress.mit.edu/sicp). Where the word closure is used for something completely different (it mentions that others use the word closure as we do here). :=( -- Piet van Oostrum [EMAIL PROTECTED] URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C4] Private email: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
python server?
Hello everybody, I am the happy yet unsatisfied owner of an ipaq 3760. I am writing a python+pygtk editor optimized for an handheld, and in the future I'd like to write more applications (to-do-list and agenda are on top of my priorities, since the existing ones don't fit my needs). I was now thinking of a way to improve memory usage. Any python application I launch takes 9-10 MB, and this risks to be a major blocking factor, since the memory I have is only 64 MB. So I'd like to share the memory between programs, sort of an emacs-server mode. I have a vague idea of the way to implement this, with a python-server.py script which would take over programs from a launcher.py script, or maybe a single script which would run into the background, the first time it is launched, and feed the programs to an already running copy, when finding an already running instance. Since I am mainly interested to GUI applications, the resulting threads should cohexist nicely. I was wondering if something similar already existed, to use as-is or to adapt to my needs. I did a little googling, which pointed me to interesting, but rather different projects. Has anybody ever seen or heard something of this kind? Or maybe there is something almost-ready in the amazing python library (as you understand, I am rather new to python), and I missed it? Thanks, Francesco. -- http://mail.python.org/mailman/listinfo/python-list
RE: WMI - Restore Setting in Python
[saw huan chng] I am beginner in Python. I have some questions on WMI Service in Python. I was able to use properties of Class Restore in WMI, but not able to use the method. Here is the sample code that I done, anyone can help me? [... snip code ...] OK, I don't actually use XP (and the SystemRestore doesn't exist on 2000) but I *strongly* suggest that if you're going to do anything with WMI you (** blows own trumpet **) use this module: http://timgolden.me.uk/python/wmi.html It does some of the dirty work you'd otherwise have to do. Effectively, the answer to your question is that Method-calling in WMI is a bit of a messy process. That's why I wrote the module to cover up the messiness. Unfortunately, there are some new areas of WMI-ness in XP which I've never really used, so the module's a bit weak in these areas. Using the wmi module, you'll have to do this (effectively untested): code import wmi connection = wmi.connect_server (., namespace=rroot\DEFAULT) sequence_number = 11 # # Bit of a hack; I need to improve the module here # system_restore = wmi._wmi_object (connection.Get (SystemRestore)) system_restore.Restore (sequence_number) /code If you really want to do it yourself, you need to do something like this: (*very* untested) code import win32com.client wmi_service = win32com.client.Dispatch (WbemSripting.SWbemLocator) wbem_services = wmi_service.ConnectServer (., rroot\DEFAULT) test_obj = wbem_services.Get (SystemRestore) sequence_number = 11 restore_method = test_obj.Methods_ (Restore) restore_params = restore_method.InParameters restore_params.Properties_ (SequenceNumber).Value = sequence_number test_obj.ExecMethod_ (Restore, restore_params) /code Hope that helps a bit TJG This e-mail has been scanned for all viruses by Star. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk -- http://mail.python.org/mailman/listinfo/python-list
Re: Python's Performance
Terry Hancock [EMAIL PROTECTED] (TH) wrote: TH He's got to be talking about runtime name-binding. In TH other words, when you refer to: TH a.spam TH the Python interpreter actually knows you labeled that attribute 'spam', TH and the string is stored in a.__dict__ , so you can also access it as TH getattr(a, 'spam') TH etc. TH I'm pretty sure this is what string internment is for, though, and TH that such lookups are optimized out pretty much whenever possible. In the case of getattr(a, 'spam') a string comparison for 'spam' has to be done. AFAIK, in the case of a.spam the string 'spam' has been interned, so that no string comparison is necessary at lookup, only a pointer comparison. Due to hash collisions probably multiple comparisons could be necessary. -- Piet van Oostrum [EMAIL PROTECTED] URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C4] Private email: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Function decorator that caches function results
Tom Anderson wrote: Okay, a crack at a definition: a closure is a function in which some of the variable names refer to variables outside the function. And i don't mean global variables - i mean somebody else's locals; call them 'remote variables'. in Python, the global variables are someone else's locals. /F -- http://mail.python.org/mailman/listinfo/python-list
win32com, generating the cache programaticaly?
Hello! I am messing around with communicating between LabVIEW and Python, got it to work by a small 'fix' (grabbing the generated file, and importing it by hand) What I might want to do, is to automatically generate the data done by executing makepy.py and run by it. What I select in makepy.py is a library LabVIEW data 7.1, I would like to do this from my program. Any hints? Then, is it possible making this on a minor mode, basically I have only to dig out the CLSID of LabVIEW data 7.1 and put it into the generated file.. sort of?? /Andy -- I do not agree with what you say, but I will defend to the death your right to say it. -- Francois Marie Arouet Voltaire (1694-1778), French philosopher, writer, Candide -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python
These are all great suggestions. Thanks to all who replied. paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Merging sorted lists/iterators/generators into one stream of values...
Lasse Vågsæther Karlsen wrote: snip Another idea for this method would be that in some cases I noticed that it was useful to know which source each element would come from as well, as well as removing duplicates from the results. snip The removing duplicates problem would probably be best as a separate function and it occurs to me that perhaps Python has such a function already. Again, this function would need the following criteria: 1. Be able to iterate through something other than a list 2. Yield the values, not return a list 3. Take an arbitrary cmp function to determine what is a duplicate As sugar, perhaps also the following criteria: - Ability to combine the duplicates through a special function A simple first-version function I hacked together does this: def unique(source, cmp=cmp, key=None, combine=None): it = iter(source) first = True value = it.next() values = [value] while True: try: value = it.next() if key is not None: cmp_result = cmp(values[0][key], value[key]) else: cmp_result = cmp(values[0], value) if cmp_result == 0: values.append(value) else: if combine is not None: yield combine(values) else: yield values[0] values = [value] except StopIteration: if combine is not None: yield combine(values) else: yield values[0] break raise StopIteration Note that this function does not do any sorting so if the source that it gets the values from is not sorted, the result will be very wrong. This is again due to my criteria of being able to handle cursors retrieving data from a database and thus avoid loading everything into memory. The combine function is passed a list of duplicate values and must return a value that will be yielded out of unique. Example of usage: def sum_counts(values): value = values[0][0] sum = 0 for row in values: sum += row[1] return value, sum fruits = [[Apple, 10], [Apple, 15], [Banana, 23], [Orange, 17], [Orange, 17]] for fruit, total_sum in unique(fruits, key=0, combine=sum_counts): print fruit, has a sum of, total_sum This will produce: Apple has a sum of 25 Banana has a sum of 23 Orange has a sum of 34 Function name is perhaps not the best one. It occurs to me that this is the GROUP BY function in SQL so perhaps a different name is better, but then again this might be moot if such a function already exists somewhere :) -- Lasse Vågsæther Karlsen http://usinglvkblog.blogspot.com/ mailto:[EMAIL PROTECTED] PGP KeyID: 0x2A42A1C2 -- http://mail.python.org/mailman/listinfo/python-list
Re: How to do *args, **kwargs properly
Lasse Vågsæther Karlsen [EMAIL PROTECTED] wrote: So what you're saying is that instead of: def fn(*values, **options): I should use: def fn(values, cmp=cmp): in this specific case? and then instead of: fn(1, 2, 3, cmp=...) this: fn([1, 2, 3], cmp=...) snip I think I'll re-write to use a list instead Actually in most cases you don't need to assume it's a list; any iterable is usually good enough. You can always turn it into a list (or a tuple or a set or..) in the function if you really have to. So when you do have to and when you don't ? You don't have to if all you do is iterate over the elements. This is true even if you want to iterate more than once; just use the itertools.tee() function to create N independent iterators. To sum up, a better signature for your function is likely to be def fn(iterable, cmp=cmp). George -- http://mail.python.org/mailman/listinfo/python-list
Re: Python's Performance
On Mon, 10 Oct 2005 16:47:35 -0700, Paul Boddie wrote: The difficulty is that the target architecture in not realized in hardware. Or isn't perhaps feasible/viable for hardware realisation: one of the EuroPython speakers dangled the promise of hardware support for high-level languages (the classic Python on a chip concept), but there are probably plenty of areas where hardware support can assist software virtual machines without going to all the trouble of implementing such virtual machines in hardware completely. I remember back in the mid 1980s, Apple and Texas Instruments collaborated to build a hybrid dual-processor machine. It had a standard Motorola 68000 CPU like the Macintosh, plus a custom TI processor that executed Lisp code in hardware. I'm told that the reason they never sold was that the Lisp machine was considerably slower than the software Lisp solution of the time. On the other hand, there were Forth enthusiasts who hacked their Macintoshes with Forth chips, and they went like a rocket. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to do *args, **kwargs properly
George Sakkis wrote: Lasse Vågsæther Karlsen [EMAIL PROTECTED] wrote: snip I think I'll re-write to use a list instead Actually in most cases you don't need to assume it's a list; any iterable is usually good enough. You can always turn it into a list (or a tuple or a set or..) in the function if you really have to. So when you do have to and when you don't ? You don't have to if all you do is iterate over the elements. This is true even if you want to iterate more than once; just use the itertools.tee() function to create N independent iterators. To sum up, a better signature for your function is likely to be def fn(iterable, cmp=cmp). Yep, that sounds like a plan :) -- Lasse Vågsæther Karlsen http://usinglvkblog.blogspot.com/ mailto:[EMAIL PROTECTED] PGP KeyID: 0x2A42A1C2 -- http://mail.python.org/mailman/listinfo/python-list
REMINDER: BayPIGgies: October 13, 7:30pm (IronPort)
The next meeting of BayPIGgies will be Thurs, October 13 at 7:30pm at IronPort. Tim Thompson will describe and demonstrate the interaction between Burning Man and Python using two applications, Radio Free Quasar and Ergo. BayPIGgies meetings alternate between IronPort (San Bruno, California) and Google (Mountain View, California). For more information and directions, see http://www.baypiggies.net/ Before the meeting, we sometimes meet at 6pm for dinner. Discussion of dinner plans is handled on the BayPIGgies mailing list. Advance notice: We've got some options on the plate for November 10 but haven't settled anything yet. Please send e-mail to [EMAIL PROTECTED] if you want to suggest an agenda (or volunteer to give a presentation). The meeting agenda for December 8 has been set. -- Aahz ([EMAIL PROTECTED]) * http://www.pythoncraft.com/ If you think it's expensive to hire a professional to do the job, wait until you hire an amateur. --Red Adair -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python
On Tue, 11 Oct 2005 18:26:58 +0900, Chris Dewin wrote: On Mon, 10 Oct 2005 17:20:35 +, dannypatterso wrote: [snip] I'm a hobby programmer using mostly BASIC(s) and some Java. I know procedural programming and I know what encapsulation, inheritance and polymorphism are but I have very little experience in using them as I've written just a few Java programs (i.e., I guess I could use a primer in OO programming). There was an excellent such primer on devshed, by Icarus, but they appear to have taken it down. I saved a copy of it to my HD. Would there be anything morally, or legally wrong with me uploading it to my site? What licence was the primer published under? Unfortunately, under copyright law, it isn't enough for the copyright owner to merely not prohibit redistribution, but they must explicitly allow it, e.g. under a Creative Commons licence. That is because when you redistribute it, you are effectively making a copy. I should also point out that copyright infringement not only opens you to law suits, but in many countries is now a felony crime. For instance, here in Australia thanks to the sarcasm wonderful /sarcasm Free Trade Agreement with the USA, the BSAA (our local branch of the American Business Software Alliance) is trumpeting the fact that they can now have company CEOs jailed for not buying enough software licences -- or, as the case may be, buying them but not being able to find them when the BSAA comes a knocking. Having said all that, if you are aware of the risks, you may make a value judgement that the copyright owner won't mind if you republish the work, e.g. because they were giving it away for free to start with. If so, I see nothing morally wrong with putting it up on your website. (The law may disagree.) -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Merging sorted lists/iterators/generators into one stream of values...
Function name is perhaps not the best one. It occurs to me that this is the GROUP BY in SQL so perhaps a different name is better, but then again this might be moot if such a already exists somewhere :) Amazing, you keep reinventing things, even with the exact same name :) from itertools import imap,groupby from operator import itemgetter for fruit,group in groupby(fruits, itemgetter(0)): print fruit, has a sum of, sum(imap(itemgetter(1),group)) For this to work as intended, fruits has to be already sorted by the same key given to grouby; otherwise just replace fruits with sorted(fruits, itemgetter(0)). By the way, read all the functions in the itertools module (http://docs.python.org/lib/itertools-functions.html), it will save you a lot of time. George -- http://mail.python.org/mailman/listinfo/python-list
Re: Python's Performance
On Mon, 10 Oct 2005 11:21:18 -0700, Donn Cave [EMAIL PROTECTED] wrote: Iron- Python). is it still an interpreter if it generates machine code? Is what an interpreter? I am not very well acquainted with these technologies, but it sounds like variations on the implementation of an interpreter, with no really compelling distinction between them. An important point made by Tannenbaum is this: Once you have a machine that executes instructions (what he called hardware or Level Zero Machine, then you can create higher level machines that execute code written in the language of that machine. For the purposes of writing C, for example, we pretend that we have this magical machine that runs C code, or more typically, the machine that runs (insert OS name) C code. When the Level n machine isn't fast enough, we go to the level n-1 machine . . . C or Java for us, or assembly, but the model remains valid until the point where you bump up against the underlying logic gates. While we don't talk about the Virtual Machine the way Java folks do, Tannenbaum's model is still useful for thinking about such things. -- http://mail.python.org/mailman/listinfo/python-list
Re: Merging sorted lists/iterators/generators into one stream of values...
George Sakkis wrote: Function name is perhaps not the best one. It occurs to me that this is the GROUP BY in SQL so perhaps a different name is better, but then again this might be moot if such a already exists somewhere :) Amazing, you keep reinventing things, even with the exact same name :) from itertools import imap,groupby from operator import itemgetter for fruit,group in groupby(fruits, itemgetter(0)): print fruit, has a sum of, sum(imap(itemgetter(1),group)) For this to work as intended, fruits has to be already sorted by the same key given to grouby; otherwise just replace fruits with sorted(fruits, itemgetter(0)). By the way, read all the functions in the itertools module (http://docs.python.org/lib/itertools-functions.html), it will save you a lot of time. George Itertools, meh, there's that wheel again :) Didn't know about this one so thank you :) -- Lasse Vågsæther Karlsen http://usinglvkblog.blogspot.com/ mailto:[EMAIL PROTECTED] PGP KeyID: 0x2A42A1C2 -- http://mail.python.org/mailman/listinfo/python-list
Re: When someone from Britain speaks, Americans hear a British accent...
On Mon, 10 Oct 2005 15:46:34 -0500, Terry Hancock [EMAIL PROTECTED] wrote: On Saturday 08 October 2005 04:35 am, Steve Holden wrote: I must have been working at NASA at the time; they are well known for embiggening prices. Not nearly as much as the DoD, from what I hear. Truthfully, I think those stories are bit exaggerated -- I think the real problem is somebody making a bad make/buy decision. They decide to make something that they could easily have bought at the hardware store. Typically, it was a $30 hammer with $270 worth of paperwork attached. The famous $10k Toilet Seat is actually a bit of an interesting tale. The part in question is the toilet from a C5A transport . . not something you can purchase at the local Home Depot. Being an aircraft toilet, it's crammed into a tiny space and has to be as light as possible and all the things you associate with aircraft toilets. When they were speccing the project, the airframe manufacturer included some number of spare toilet seats in the bid, given the expected life of the airframe. Some faceless bureaucrat decided that they didn't NEED any spare toilet seats and cancelled that line item. Lo and Behold, they eventually needed spare toilet seats. But because of Another Good Regulation (tm) the tooling had been recycled. Recreating the tooling to make the spares was, amortized over the number ordered, around $10k/seat. Compared to the tooling costs, subsequent orders of the same seat are pretty much free . . . at least until some bozo in Ring A decides to toss the tooling again. -- http://mail.python.org/mailman/listinfo/python-list
HELP: Searching File Manager written in Python
Hi, I am googeling some hours now ... still without result. So I have a question: Does somebody know a filemanager: - which looks like Norton Commander/7-Zip Filemanager - where I can add python scripts which I can execute on a selected file I already looked at wxpyatol but its not what I search, and its no more developped. Thanks Stephane -- http://mail.python.org/mailman/listinfo/python-list
Can module access global from __main__?
Suppose I have a main program, e.g., A.py. In A.py we have: X = 2 import B Now B is a module B.py. In B, how can we access the value of X? -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for info on Python's memory allocation
On Tue, 11 Oct 2005 11:22:39 +0200, Lasse Vågsæther Karlsen wrote: This begs a different question along the same lines. Er, no it doesn't. Begs the question does _not_ mean asks the question or suggests the question. It means assumes the truth of that which needs to be proven. http://en.wikipedia.org/wiki/Begging_the_question http://www.worldwidewords.org/qa/qa-beg1.htm (Both of these sources are far more forgiving of the modern mis-usage than I am. Obviously.) If I have a generator or other iterable producing a vast number of items, and use it like this: s = [k for k in iterable] if I know beforehand how many items iterable would possibly yield, would a construct like this be faster and use less memory? s = [0] * len(iterable) for i in xrange(len(iterable)): s[i] = iterable.next() Faster? Maybe. Only testing can tell -- but I doubt it. But as for less memory, look at the two situations. In the first, you create a list of N objects. In the second, you end up with the same list of N objects, plus an xrange object, which may be bigger or smaller than an ordinary list of N integers, depending on how large N is. So it won't use *less* memory -- at best, it will use just slightly more. Is there a way from within Python to find out how much memory a single object uses, and how much memory Python is using in total? -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: date reformatting
Bell, Kevin wrote:
Anyone aware of existing code to turn a date string 8-15-05 into the
number 20050815?
import datetime
s = 8-15-05
month,day,year = map(int, s.split('-'))
date = datetime.date(2000+year,month,day)
date.strftime('%Y%m%d')
'20050815'
Of course, if you really want the *number* 20050815 you'd
have to do
int(date.strftime('%Y%m%d'))
Using a datetime.date object means that you have good
support for a lot of arithmetic on and formatting of
dates without writing a lot of new code.
If you really mean that you want the number 20050815, I
assume this is because some legacy system beyond you control
need to have dates in that format. It's not a particularly
good format for dates. If you just want a numeric storage of
dates, I'd suggest using datetime.date.toordinal/fromordinal.
Those numbers aren't as easy to decipher manually, but at
least they work right if you subtract dates or add or subtract
days from a date.
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to do *args, **kwargs properly
Lasse Vågsæther Karlsen wrote: Max M wrote: So what you're saying is that instead of: def fn(*values, **options): I should use: def fn(values, cmp=cmp): in this specific case? and then instead of: fn(1, 2, 3, cmp=...) this: fn([1, 2, 3], cmp=...) Precisely. Sometimes you need different interfaces for a method. In that case it is fine. But if you are just doing it instead of passing sequences, you are just (ab)using the * and ** operators. The method definition, like any python code, is made for humans not machines. The more obvious you can make the function definition, the happier anyone will be. -- hilsen/regards Max M, Denmark http://www.mxm.dk/ IT's Mad Science -- http://mail.python.org/mailman/listinfo/python-list
Re: strange import error with Python-2.4.1
Fredrik Lundh wrote: Steve Holden wrote: Can I ask if you are specifying a source encoding in your file with a pragma (?) like # -*- coding: iso-8859-15 -*- I've noticed what appear to be spurious syntax errors from time to time on such files, and have been attempting to debug the problem for some time without any apparent success. http://www.python.org/sf/1175396 /F thanks that looks like it, the __init__.py had # -*- coding: cp1252 -*- at the start. -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
how to(can we ?) pass argument to .py script ?
howdy~ i wrote a .py file and it works fine, my goal is to pass argument to that py file when it get executed, and accept that argument within py file, eg. i prefer a command like below: python test.py -t and then, i may get -t within test.py for later use. i have no ideas how to do and i'm really stuck, can anyone help ? -- http://mail.python.org/mailman/listinfo/python-list
ANN: Kamaelia 0.3.0 released!
Kamaelia 0.3.0 has been released! Introduction Kamaelia is a networking/communications infrastructure for innovative multimedia systems. Kamaelia uses a component architecture designed to simplify creation and testing of new protocols and large scale media delivery systems. A subset of the system has been tested on series 60 phones. General feedback is welcome either directly, mailing lists or via IRC (#kamaelia, freenode). People are also more than welcome to use the system and suggest improvements not directly related to our specific goals, because we recognise the system can be used in more areas, not just networked multimedia. A diversity of systems built improves the system (for all users of course!) as a whole. What's New Changed? = *NOTE* Kamaelia 0.3.0 requires Axon-1.1.2 to run for some newer components (which has also just been released). Full release notes and change log: * http://kamaelia.sourceforge.net/Kamaelia-0.3.0-ReleaseNotes.html New Examples - 7 new examples including: * Simple reliable multicast based streamer using Ogg Vorbis. * Dirac Player * Dirac encode playback. * Simple bouncing images game. Designed for very small children who are amused by things take beep and react when you press left/right mouse buttons. * Simple example showing how to use the ticker (First developed for showing subtitles). * Demonstration system showing how to use the new software chassis facility in the context of multiple chassis. New Tools, Notable Additions * Visual tool for building Kamaelia pipelines * Tk Support * Video encode, decode and playback. (dirac) New Packages Subsystems These names should provide you with a flavour of the new subsystems that have been added: * Kamaelia.Codec * Kamaelia.Chassis * Kamaelia.File * Kamaelia.UI.Tk * Kamaelia.Internet.Simulate Other Highlights * Software chassis (software backplane will be coming in Kamaelia-NEXT) * Tk integration. (The pipeline builder is a nice example of a tool this enables) * Dirac encoded video decoders and encoders * Support for video playback. (dirac YUV) * Variety of pygame based components, including * Tools for greater control over the pygame surface managed environment * Tools for building simple games. (controlling sprite behaviour for example) * Much richer tools for file reading and writing * Includes re-usable file readers. * More utilities for message filters and splitting of messages * Basic tools for simuluating error conditions and failure rates for delivery of messages (Sufficient for simulating an unstable underlying internet infrastructure). What is Kamaelia? = The project aims to make it easy to build networked multimedia systems (eg audio, video, interactive systems). The result is systems which are naturally componentised. Also, the resulting systems are /naturally concurrent/ allowing quick and fast reuse in the same way as Unix pipelines do. It is designed as a practical toolkit, such that you can build systems such as: * Ogg Vorbis streaming server/client systems (via vorbissimple) * Create Video players streaming systems (for dirac). * With subtitles. * Simple network aware games (via pygame) * Quickly build TCP Multicast based network servers and clients * Presentation tools * A networked audio mixer matrix (think multiple audio sources over network connections mixed and sent on to multiple locations with different mixes) * Look at graph topologies customise the rules of display particle types. Mix and match all of the above. You can also do a lot of this *visually* using the new PipeBuilder application in Tools. Essentially if the system you want to build involves audio or moving pictures, and you want to be able to make the system network aware, then this should be quick and easy to do using Kamaelia. (If it isn't, then a) it's a bug b) needs improving :-) It runs on Linux, Window, Mac OS X with a subset running on Series 60 phones. The basic underlying metaphor of a component us like an office worker with inboxes and outboxes, with deliveries occuring between desks, offices, and depts. The component can thus do work anyway it likes but only communicates with these inboxes and outboxes. Like office workers, components run in parallel, and to achieve this are generally implemented using python generators, but can also used threads. The rationale behind the project is to provide a toolkit enabling the development of new protocols, including streaming, for large scale media delivery. The license essentially allows use in proprietary systems without change, but all changes to the system itself must be shared. Oh, and due to things like the visual editor, the use of pygame in a lot of examples, the use of dirac vorbis, it's quite a
Re: Can module access global from __main__?
Neal Becker wrote: Suppose I have a main program, e.g., A.py. In A.py we have: X = 2 import B Now B is a module B.py. In B, how can we access the value of X? Without trying in any way to dodge the question, why do you want to do that? There's a property of software called coupling that's used to describe the way that communications take place between different components of a piece of software. Ideally modules should be loosely-coupled, which is usually achieved by passing values in as function or method arguments and receiving the results as the return values of said functions or methods. When a module is loosely-coupled in this way it's possible to revise the structure of one component completely (while maintaining the same interface specification) without affecting any other component. By introducing some magic load a variable from the namespace of the importing module you make your modules tightly-coupled, which is very bad for maintainability: what happens if you now import B.py into a module that doesn't create an X in its namespace? The fact that you ask the question implies that you really need to think a little harder about the structure of your program. If you tell us the *real* problem (back to my why do you want to do that question ...) perhaps we can suggest a better-structured solution. regards Steve PS: If A is the main program (the module that you have run) then you should be able to access it as __main__.X, but you'd be *very naughty* to do so :-) -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
Re: how to(can we ?) pass argument to .py script ?
On 11 Oct 2005 07:07:44 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: i wrote a .py file and it works fine, my goal is to pass argument to that py file when it get executed, and accept that argument within py file, eg. i prefer a command like below: python test.py -t and then, i may get -t within test.py for later use. i have no ideas how to do and i'm really stuck, can anyone help ? Short answer: import sys print sys.argv You might also want to take to butchers at the optparse module. -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
