Mailman 3 September 2002 - Python-Dev

New `spambayes' project on SourceForge
by barry＠zope.com 05 Sep '02

05 Sep '02

There's been a ton of press about applying Bayesian classifiers to spam detection lately, spurred on by Paul Graham's recent paper "A Plan for Spam" http://www.paulgraham.com/spam.html Tim Peters has done an incredible amount of work on our Python implementation of this idea. Some of the reasons why I think Tim's work is so cool is that he's brought along his deep knowledge of speech recognition's related issues, and his obsessive devotion to reducing the amount of spam I ultimately have to delete <wink>. In order to encourage more participation from the wider open source community, we've moved the code from a backwater of the Python cvs tree to its own project on SourceForge. The hope is that more people will be able to contribute to ideas, testing, and integration of the basic algorithms with other systems such as mail daemons, mailing list managers, and mail clients. The project is called "spambayes" (for lack of creativity on our part :) and is hosted here: http://sf.net/projects/spambayes If you're interested in becoming a developer on the project, let me know. Otherwise you can of course get anonymous checkouts of the code. There are also two mailing lists related to the spambayes project. The first is a general discussion list: http://mail.python.org/mailman-21/listinfo/spambayes and the other is a list for cvs checkin message notices: http://mail.python.org/mailman-21/listinfo/spambayes-checkins Feel free to join those lists (and help be a guinea pig for Mailman 2.1 :). Enjoy, -Barry PS to Python-devers: the code has been removed from nondist/sandbox/spambayes, so you won't be able to hack on it there. Also, please move discussion about this from python-dev(a)python.org to spambayes(a)python.org

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GBayes design
by Raymond Hettinger 05 Sep '02

05 Sep '02

Is it too late to challenge a core design decision? Instead of multiplying probablities, use fuzzy logic methods. Classify the indicators into damning, strong, weak, neautral, ... After counting the number of indicators in each class, make a spam/ham decision that can be easily tweaked. This would make it easy to implement variations of Tim's recent clear win, where additional indicators are gathered until the balance shifts sharply to one side. Some other advantages are: -- easily interpreted score vectors (6 damning, 7 strong, 4 weak, ... ) -- avoids mathematical issues with indicators not being independent -- allows the addition of non-token based indicators. for instance, a preponderance of caps would be a weak indicator. the presence of caps separated by spaces would be a strong indicator. -- the decision logic would be more intuitive -- avoids the issue of having equal amounts of spam and ham in the sample The core concept would stay the same -- it's really just a shift from continuous to discrete. of-course-this-is-entirely-outside-my-fields-of-knowledge-ly yours, Raymond Hettinger

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Getting started with GBayes testing
by Brad Clements 05 Sep '02

05 Sep '02

Hi, I'm interested in contributing to GBayes .. I'm thinking of trying word stemming and adding other types of token indicators. How can I contribute? Btw, I have been saving up my spam for a year or so.. I have about 31,238 spam messages saved up now. These are categorized as spam based on my reading of the subject, or examining the body when in doubt. There are probably 10% dups in the corpus. Some of them have viruses, likely klez. I'd like to replicate Tim's test rig so I can compare my results with existing ones. My spam isn't in mbox format, but I can convert it.. I'm particularly intersted in how to allow html only messages (reduce false positives). I'm getting a lot of personal mail in that format, unfortunately. Brad Clements, bkc(a)murkworks.com (315)268-1000 http://www.murkworks.com (315)268-9812 Fax AOL-IM: BKClements

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Proposed Mixins for Wide Interfaces
by Raymond Hettinger 05 Sep '02

05 Sep '02

How about adding some mixins to simplify the implementation of some of the fatter interfaces? class CompareMixin: """ Given an __eq__ method in a subclass, adds a __ne__ method Given __eq__ and __lt__, adds !=, <=, >, >=. """ class MappingMixin: """ Given __setitem__, __getitem__, and keys, implements values, items, update, get, setdefault, len, iterkeys, iteritems, itervalues, has_key, and __contains__. If __delitem__ is also supplied, implements clear, pop, and popitem. Takes advantage of __iter__ if supplied (recommended). Takes advantage of __contains__ or has_key if supplied (recommended). """ The idea is to make it easier to implement these interfaces. Also, if the interfaces get expanded, the clients automatically updated. Raymond Hettinger

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Re: [Python-Dev] Please help in calling python fucntion from 'c'
by Michael Hudson 05 Sep '02

05 Sep '02

"Praveen Patil" <praveen.patil(a)silver-software.com> writes: > This is a multi-part message in MIME format. > ------=_NextPart_000_0011_01C25417.4EC8F910 > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: 7bit > > Hi, > > I have written 'C' dll(MY_DLL.DLL) . I am importing 'C' dll in python > file(example.py). > I want to call python function from 'c' function. > For your reference I have attached 'c' and python files to this mail. > In my pc: > python code is under the directory D:\test\example.py > dll is under the directory C:\Program Files\Python\DLLs\MY_DLL.pyd > > Here are the steps I am following. > > step(1): I am calling 'C' function(RECEIVE_FROM_IL_S) from python. > This 'C' function is existing imported dll(MY_DLL). > step(2): I want to call python function(TestFunction) from 'C' > function(RECEIVE_FROM_IL_S). > > > Python code is(example.py) :- > ---------------------------- > import MY_DLL > > G_Logfile = None > > def TestFunction(): > G_Logfile = open('Pytestfile.txt', 'w') > G_Logfile.write("%s \n"%'I am writing python created text file') > G_Logfile.close > G_Logfile = None > #end def TestFunction > > if __name__ == "__main__": > > MY_DLL.RECEIVE_FROM_IL_S(10,50) > > > 'C' code is (MY_DLL.c) :- > --------------------- > #include <windows.h> > #include <stdio.h> > #include <Python.h> > > PyObject* _wrap_RECEIVE_FROM_IL_S(PyObject *self, PyObject *args) > { > FILE* fp; > PyObject* _resultobj; > int i,j; > > if( !(PyArg_ParseTuple(args, "ii",&i,&j))) > { > return NULL; > } > fp= fopen("RECEIVE_IL_S.txt", "w"); > fprintf(fp, "i=%d j=%d" , i,j); > fclose(fp); > > /* Here I want to call python function(TestFunction). Please suggest me > some solution*/ > > _resultobj = Py_None; > return _resultobj; > } > > > static PyMethodDef MY_DLL_methods[] = { > { "RECEIVE_FROM_IL_S", _wrap_RECEIVE_FROM_IL_S, METH_VARARGS }, > { NULL , NULL} > }; > > __declspec(dllexport) void __cdecl initMY_DLL(void) > { > Py_InitModule("MY_DLL",MY_DLL_methods); > } > > > Please anybody help me solving the problem. > > > Cheers, > > Praveen. > > ------=_NextPart_000_0011_01C25417.4EC8F910 > Content-Type: text/plain; > name="exampl.py" > Content-Transfer-Encoding: 7bit > Content-Disposition: attachment; > filename="exampl.py" > > import MY_DLL > > G_Logfile = None > > def TestFunction(): > G_Logfile = open('Pytestfile.txt', 'w') > G_Logfile.write("%s \n"%'I am writing python created text file') > G_Logfile.close > G_Logfile = None > #end def TestFunction > > if __name__ == "__main__": > > MY_DLL.RECEIVE_FROM_IL_S(10,50) > > ------=_NextPart_000_0011_01C25417.4EC8F910 > Content-Type: application/octet-stream; > name="MY_DLL.c" > Content-Transfer-Encoding: quoted-printable > Content-Disposition: attachment; > filename="MY_DLL.c" > > #include <windows.h> > #include <stdio.h> > #include <Python.h> > > PyObject* _wrap_RECEIVE_FROM_IL_S(PyObject *self, PyObject *args) > { > FILE* fp; =20 > PyObject* _resultobj; > int i,j; > =20 > if( !(PyArg_ParseTuple(args, "ii",&i,&j))) > { > return NULL; > } > fp=3D fopen("RECEIVE_IL_S.txt", "w"); > fprintf(fp, "i=3D%d j=3D%d" , i,j); > fclose(fp); > > /* Here I want to call python function(TestFunction). Please suggest = > me some solution*/ > > _resultobj =3D Py_None; > return _resultobj; > } > > > static PyMethodDef MY_DLL_methods[] =3D { > { "RECEIVE_FROM_IL_S", _wrap_RECEIVE_FROM_IL_S, METH_VARARGS }, > { NULL , NULL} > }; > > __declspec(dllexport) void __cdecl initMY_DLL(void) > { > Py_InitModule("MY_DLL",MY_DLL_methods); > } > > ------=_NextPart_000_0011_01C25417.4EC8F910 > Content-Type: text/plain; charset="us-ascii" > Content-Transfer-Encoding: 7bit > Content-Disposition: inline > > [ The information contained in this e-mail is confidential and is intended for the named recipient only. If you are not the named recipient, please notify us by telephone on +44 (0)1249 442 430 immediately, destroy the message and delete it from your computer. Silver Software has taken every reasonable precaution to ensure that any attachment to this e-mail has been checked for viruses. However, we cannot accept liability for any damage sustained as a result of any such software viruses and advise you to carry out your own virus check before opening any attachment. Furthermore, we do not accept responsibility for any change made to this message after it was sent by the sender.] > > ------=_NextPart_000_0011_01C25417.4EC8F910-- > > _______________________________________________ > Python-Dev mailing list > Python-Dev(a)python.org > http://mail.python.org/mailman/listinfo/python-dev --

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Re: [Python-Dev] Signal-resistant code (was: Two random and nearly unrelated ideas)
by Michael Hudson 05 Sep '02

05 Sep '02

Oren Tirosh <oren-py-d(a)hishome.net> writes: > Any other problems I should be aware of? Wildly unpredicatble x-platform behaviour in the presence of threads. M. -- Indeed, when I design my killer language, the identifiers "foo" and "bar" will be reserved words, never used, and not even mentioned in the reference manual. Any program using one will simply dump core without comment. Multitudes will rejoice. -- Tim Peters, 29 Apr 1998

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The first trustworthy <wink> GBayes results
by Tim Peters 05 Sep '02

05 Sep '02

Setting this up has been a bitch. All early attempts floundered because it turned out there was *some* systematic difference between the ham and spam archives that made the job trivial. The ham archive: I selected 20,000 messages, and broke them into 5 sets of 4,000 each, at random, from a python-list archive Barry put together, containing msgs only after SpamAssassin was put into play on python.org. It's hoped that's pretty clean, but nobody checked all ~= 160,000+ msgs. As will be seen below, it's not clean enough. The spam archive: This is essentially all of Bruce Guenter's 2002 spam collection, at <http://www.em.ca/~bruceg/spam/>. It was broken at random into 5 sets of 2,750 spams each. Problems included: + Mailman added distinctive headers to every message in the ham archive, which appear nowhere in the spam archive. A Bayesian classifier picks up on that immediately. + Mailman also adds "[name-of-list]" to every Subject line. + The spam headers had tons of clues about Bruce Guenter's mailing addresses that appear nowhere in the ham headers. + The spam archive has Windows line ends (\r\n), but the ham archive plain Unix \n. This turned out to be a killer clue(!) in the simplest character n-gram attempts. (Note: I can't use text mode to read msgs, because there are binary characters in the archives that Windows treats as EOF in text mode -- indeed, 400MB of the ham archive vanishes when read in text mode!) What I'm reporting on here is after normalizing all line-ends to \n, and ignoring the headers *completely*. There are obviously good clues in the headers, the problem is that they're killer-good clues for accidental reasons in this test data. I don't want to write code to suppress these clues either, as then I'd be testing some mix of my insights (or lack thereof) with what a blind classifier would do. But I don't care how good I am, I only care about how well the algorithm does. Since it's ignoring the headers, I think it's safe to view this as a lower bound on what can be achieved. There's another way this should be a lower bound: def tokenize_split(string): for w in string.split(): yield w tokenize = tokenize_split class Msg(object): def __init__(self, dir, name): path = dir + "/" + name self.path = path f = file(path, 'rb') guts = f.read() f.close() # Skip the headers. i = guts.find('\n\n') if i >= 0: guts = guts[i+2:] self.guts = guts def __iter__(self): return tokenize(self.guts) This is about the stupidest tokenizer imaginable, merely splitting the body on whitespace. Here's the output from the first run, training against one pair of spam+ham groups, then seeing how its predictions stack up against each of the four other pairs of spam+ham groups: Training on Data/Ham/Set1 and Data/Spam/Set1 ... 4000 hams and 2750 spams testing against Data/Spam/Set2 and Data/Ham/Set2 tested 4000 hams and 2750 spams false positive: 0.00725 (i.e., under 1%) false negative: 0.0530909090909 (i.e., over 5%) testing against Data/Spam/Set3 and Data/Ham/Set3 tested 4000 hams and 2750 spams false positive: 0.007 false negative: 0.056 testing against Data/Spam/Set4 and Data/Ham/Set4 tested 4000 hams and 2750 spams false positive: 0.0065 false negative: 0.0545454545455 testing against Data/Spam/Set5 and Data/Ham/Set5 tested 4000 hams and 2750 spams false positive: 0.00675 false negative: 0.0516363636364 It's a Good Sign that the false positive/negative rates are very close across the four test runs. It's possible to quantify just how good a sign that is, but they're so close by eyeball that there's no point in bothering. This is using the new Tester.py in the sandbox, and that class automatically remembers the false positives and negatives. Here's the start of the first false positive from the first run: """ It's not really hard!! Turn $6.00 into $1,000 or more...read this to find out how!! READING THIS COULD CHANGE YOUR LIFE!! I found this on a bulletin board anddecided to try it. A little while back, while chatting on the internet, I came across an article similar to this that said you could make thousands of dollars in cash within weeks with only an initial investment of $6.00! So I thought, "Yeah right, this must be a scam", but like most of us, I was curious, so I kept reading. Anyway, it said that you send $1.00 to each of the six names and address statedin the article. You then place your own name and address in the bottom of the list at #6, and post the article in at least 200 newsgroups (There are thousands) or e-mail them. No """ Call me forgiving, but I think it's vaguely possible that this should have been in the spam corpus instead <wink>. Here's the start of the second false positive: """ Please forward this message to anyone you know who is active in the stock market. See Below for Press Release xXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxX Dear Friends, I am a normal investor same as you. I am not a finance professional nor am I connected to FDNI in any way. I recently stumbled onto this OTC stock (FDNI) while searching through yahoo for small float, big potential stocks. At the time, the company had released a press release which stated they were doing a stock buyback. Intrigued, I bought 5,000 shares at $.75 each. The stock went to $1.50 and I sold my shares. I then bought them back at $1.15. The company then circulated another press release about a foreign acquisition (see below). The stock jumped to $2.75 (I sold @ $2.50 for a massive profit). I then bought back in at $1.25 where I am holding until the next major piece of news. """ Here's the start of the third: """ Grand Treasure Industrial Limited Contact Information We are a manufacturer and exporter in Hong Kong for all kinds of plastic products, We export to worldwide markets. Recently , we join-ventured with a bag factory in China produce all kinds of shopping , lady's , traveller's bags.... visit our page and send us your enquiry by email now. Contact Address : Rm. 1905, Asian Trade Centre , 79 Lei Muk Rd, Tsuen Wan , Hong Kong. Telephone : ( 852 ) 2408 9382 """ That is, all the "false positives" there are blatant spam. It will take a long time to sort this all out, but I want to make a point here now: the classifier works so well that it can *help* clean the ham corpus! I haven't found a non-spam among the "false positives" yet. Another lesson reinforces one from my previous life in speech recognition: rigorous data collection, cleaning, tagging and maintenance is crucial when working with statisical approaches, and is damned expensive to do. Here's the start of the first "false negative" (including the headers): """ Return-Path: <911(a)911.COM> Delivered-To: em-ca-bruceg(a)em.ca Received: (qmail 24322 invoked from network); 28 Jul 2002 12:51:44 -0000 Received: from unknown (HELO PC-5.) (61.48.16.65) by churchill.factcomp.com with SMTP; 28 Jul 2002 12:51:44 -0000 x-esmtp: 0 0 1 Message-ID: <1604543-22002702894513952(a)smtp.vip.sina.com> To: "NEW020515" <911(a)911.COM> From: "ÖÐ¹úITÊý¾Ý¿âÍøÕ¾£¨www.itdatabase.net £©" <911(a)911.COM> Subject: ÖÐ¹úITÊý¾Ý¿âÍøÕ¾£¨www.itdatabase.net £© Date: Sun, 28 Jul 2002 17:45:13 +0800 MIME-Version: 1.0 Content-type: text/plain; charset=gb2312 Content-Transfer-Encoding: quoted-printable Content-Length: 977 =D6=D0=B9=FAIT=CA=FD=BE=DD=BF=E2=CD=F8=D5=BE=A3=A8www=2Eitdatabase=2Enet =A3= =A9=CC=E1=B9=A9=B4=F3=C1=BF=D3=D0=B9=D8=D6=D0=B9=FAIT/=CD=A8=D0=C5=CA=D0=B3= =A1=D2=D4=BC=B0=C8=AB=C7=F2IT/=CD=A8=D0=C5=CA=D0=B3=A1=B5=C4=CF=E0=B9=D8=CA= =FD=BE=DD=BA=CD=B7=D6=CE=F6=A1=A3 =B1=BE=CD=F8=D5=BE=C9=E6=BC=B0=D3=D0=B9=D8= =B5=E7=D0=C5=D4=CB=D3=AA=CA=D0=B3=A1=A1=A2=B5=E7=D0=C5=D4=CB=D3=AA=C9=CC=A1= """ Since I'm ignoring the headers, and the tokenizer is just a whitespace split, each line of quoted-printable looks like a single word to the classifier. Since it's never seen these "words" before, it has no reason to believe they're either spam or ham indicators, and favors calling it ham. One more mondo cool thing and that's it for now. The GrahamBayes class keeps track of how many times each word makes it into the list of the 15 strongest indicators. These are the "killer clues" the classifier gets the most value from. The most valuable spam indicator turned out to be " " -- there's simply almost no HTML mail in the ham archive (but note that this clue would be missed if you stripped HTML!). You're never going to guess what the most valuable non-spam indicator was, but it's quite plausible after you see it. Go ahead, guess. Chicken <wink>. Here are the 15 most-used killer clues across the runs shown above: the repr of the word, followed by the # of times it made into the 15-best list, and the estimated probability that a msg is spam if it contains this word: testing against Data/Spam/Set2 and Data/Ham/Set2 best discrimators: 'Helvetica,' 243 0.99 'object' 245 0.01 'language' 258 0.01 ' ' 292 0.99 '>' 339 0.179104 'def' 397 0.01 'article' 423 0.01 'module' 436 0.01 'import' 499 0.01 ' ' 652 0.99 '>>>' 667 0.01 'wrote' 677 0.01 'python' 755 0.01 'Python' 1947 0.01 'wrote:' 1988 0.01 testing against Data/Spam/Set3 and Data/Ham/Set3 best discrimators: 'string' 494 0.01 'Helvetica,' 496 0.99 'language' 524 0.01 ' ' 553 0.99 '>' 687 0.179104 'article' 851 0.01 'module' 857 0.01 'def' 875 0.01 'import' 1019 0.01 ' ' 1288 0.99 '>>>' 1344 0.01 'wrote' 1355 0.01 'python' 1461 0.01 'Python' 3858 0.01 'wrote:' 3984 0.01 testing against Data/Spam/Set4 and Data/Ham/Set4 best discrimators: 'object' 749 0.01 'Helvetica,' 757 0.99 'language' 763 0.01 ' ' 877 0.99 '>' 954 0.179104 'article' 1240 0.01 'module' 1260 0.01 'def' 1364 0.01 'import' 1517 0.01 ' ' 1765 0.99 '>>>' 1999 0.01 'wrote' 2071 0.01 'python' 2160 0.01 'Python' 5848 0.01 'wrote:' 6021 0.01 testing against Data/Spam/Set5 and Data/Ham/Set5 best discrimators: 'object' 980 0.01 'language' 992 0.01 'Helvetica,' 1005 0.99 ' ' 1139 0.99 '>' 1257 0.179104 'article' 1678 0.01 'module' 1702 0.01 'def' 1846 0.01 'import' 2003 0.01 ' ' 2387 0.99 '>>>' 2624 0.01 'wrote' 2743 0.01 'python' 2864 0.01 'Python' 7830 0.01 'wrote:' 8060 0.01 Note that an "intelligent" tokenizer would likely miss that the Python prompt ('>>>') is a great non-spam indicator on python-list. I've had this argument with some of you before <wink>, but the best way to let this kind of thing be as intelligent as it can be is not to try to help it too much: it will learn things you'll never dream of, provided only you don't filter clues out in an attempt to be clever. everything's-a-clue-ly y'rs - tim

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Re: [Python-checkins] python/nondist/sandbox/spambayes classifier.py,1.8,1.9
by barry＠python.org 05 Sep '02

05 Sep '02

>>>>> "RH" == Raymond Hettinger <python(a)rcn.com> writes: >> A now-rare pure win, changing spamprob() to work harder to find >> more evidence when competing 0.01 and 0.99 clues appear RH> I hope these victories make it back to the world outside of RH> Python (assuming there is one). The world needs good spam RH> filters. Indeed, I too hope they will. I just got approved for a SF project called "spambayes" and plan to move the code there. I'll try to coordinate that with Tim, and then make a more detailed announcement tomorrow. -Barry

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mimetypes patch #554192
by Walter Dörwald 04 Sep '02

04 Sep '02

Patch http://www.python.org/sf/554192 adds a function to mimetypes.py that returns all known extensions for a mimetype, e.g. >>> import mimetypes >>> mimetypes.guess_all_extensions("image/jpeg") ['.jpg', '.jpe', '.jpeg'] Martin v. Loewis and I were discussing whether it would make sense to make the helper method add_type (which is used for adding a mapping between one type and one extension) visible on the module level. Any comments? Bye, Walter Dörwald

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Please help in calling python fucntion from 'c'
by Praveen Patil 04 Sep '02

04 Sep '02

Hi, I have written 'C' dll(MY_DLL.DLL) . I am importing 'C' dll in python file(example.py). I want to call python function from 'c' function. For your reference I have attached 'c' and python files to this mail. In my pc: python code is under the directory D:\test\example.py dll is under the directory C:\Program Files\Python\DLLs\MY_DLL.pyd Here are the steps I am following. step(1): I am calling 'C' function(RECEIVE_FROM_IL_S) from python. This 'C' function is existing imported dll(MY_DLL). step(2): I want to call python function(TestFunction) from 'C' function(RECEIVE_FROM_IL_S). Python code is(example.py) :- ---------------------------- import MY_DLL G_Logfile = None def TestFunction(): G_Logfile = open('Pytestfile.txt', 'w') G_Logfile.write("%s \n"%'I am writing python created text file') G_Logfile.close G_Logfile = None #end def TestFunction if __name__ == "__main__": MY_DLL.RECEIVE_FROM_IL_S(10,50) 'C' code is (MY_DLL.c) :- --------------------- #include <windows.h> #include <stdio.h> #include <Python.h> PyObject* _wrap_RECEIVE_FROM_IL_S(PyObject *self, PyObject *args) { FILE* fp; PyObject* _resultobj; int i,j; if( !(PyArg_ParseTuple(args, "ii",&i,&j))) { return NULL; } fp= fopen("RECEIVE_IL_S.txt", "w"); fprintf(fp, "i=%d j=%d" , i,j); fclose(fp); /* Here I want to call python function(TestFunction). Please suggest me some solution*/ _resultobj = Py_None; return _resultobj; } static PyMethodDef MY_DLL_methods[] = { { "RECEIVE_FROM_IL_S", _wrap_RECEIVE_FROM_IL_S, METH_VARARGS }, { NULL , NULL} }; __declspec(dllexport) void __cdecl initMY_DLL(void) { Py_InitModule("MY_DLL",MY_DLL_methods); } Please anybody help me solving the problem. Cheers, Praveen. [ The information contained in this e-mail is confidential and is intended for the named recipient only. If you are not the named recipient, please notify us by telephone on +44 (0)1249 442 430 immediately, destroy the message and delete it from your computer. Silver Software has taken every reasonable precaution to ensure that any attachment to this e-mail has been checked for viruses. However, we cannot accept liability for any damage sustained as a result of any such software viruses and advise you to carry out your own virus check before opening any attachment. Furthermore, we do not accept responsibility for any change made to this message after it was sent by the sender.]

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