Re: calculating on matrix indices
Brian Blais wrote: > Colin J. Williams wrote: > >> Brian Blais wrote: >> >>> In my attempt to learn python, migrating from matlab, I have the >>> following problem. Here is what I want to do, (with the wrong syntax): >>> >>> from numpy import * >>> >>> t=arange(0,20,.1) >>> x=zeros(len(t),'f') >>> >>> idx=(t>5)# <---this produces a Boolean array, >>> probably not what you want. >>> tau=5 >>> x[idx]=exp(-t[idx]/tau) # <---this line is wrong (gives a TypeError) >>> >> What are you trying to do? It is most unlikely that you need Boolean >> values in x[idx] [Apologies for piggybacking.] Boolean arrays are perfectly valid indices and do exactly what the OP wants. In [25]: t[idx] Out[25]: array([ 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6. , 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7. , 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8. , 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9. , 9.1, 9.2, 9.3, 9.4, 9.5, ... In [28]: (t[idx] == compress(idx, t)).all() Out[28]: True When used as indices, Boolean arrays are treated as arrays of Boolean values, not 0s and 1s. Arrays of 0s and 1s used as indices would get the first and second values of an array, respectively, as I think you were expecting. In [35]: t[idx.astype(int)] Out[35]: array([ 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, ... -- Robert Kern [EMAIL PROTECTED] "In the fields of hell where the grass grows high Are the graves of dreams allowed to die." -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
Re: Seaching Active Directory via ADO
Never mind , I know what's wrong ... need to use the right account. It works
great and is a great example .. thx
"LittlePython" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Do you know what this may mean?
>
> C:\Documents and Settings\Administrator\Desktop\pytest>ADOSeach.py
> Traceback (most recent call last):
> File "C:\Documents and
Settings\Administrator\Desktop\pytest\ADOSeach.py",
> lin
> e 6, in ?
> rs,rc=c.Execute("""
> File "", line 3, in Execute
> File "C:\Python24\Lib\site-packages\win32com\client\dynamic.py", line
258,
> in
> _ApplyTypes_
> result = self._oleobj_.InvokeTypes(*(dispid, LCID, wFlags, retType,
> argTypes
> ) + args)
> pywintypes.com_error: (-2147352567, 'Exception occurred.', (0, 'Provider',
> 'Tabl
> e does not exist.', None, 1240640, -2147217865), None)
>
> C:\Documents and Settings\Administrator\Desktop\pytest>
> "Roger Upole" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
> > You could also accomplish the same thing using the
> > Command object, but this way is usually more concise
> > for plain Sql.
> >
> > Roger
> >
> > "LittlePython" <[EMAIL PROTECTED]> wrote in message
> > news:[EMAIL PROTECTED]
> > > I notice there is no adodb.command. This is not required?
> > > Thx for the example!
> > > "Roger Upole" <[EMAIL PROTECTED]> wrote in message
> > > news:[EMAIL PROTECTED]
> > > > Here's a short example that uses ADO to search for a
> > > > user by wildcard.
> > > >
> > > > import win32com.client
> > > > c = win32com.client.Dispatch("ADODB.Connection")
> > > > c.Open("Provider=ADSDSOObject")
> > > >
> > > > rs,rc=c.Execute("""
> > > > SELECT adspath, title, name
> > > > From 'LDAP://DC=yourdomain, DC=COM'
> > > > where objectClass='user' and name='Roger*'
> > > > """)
> > > >
> > > > while not rs.EOF:
> > > > for f in rs.Fields:
> > > > print f.Name, f.Value
> > > > rs.MoveNext()
> > > >
> > > > hth
> > > > Roger
> > > >
> > > > "LittlePython" <[EMAIL PROTECTED]> wrote in message
> > > > news:[EMAIL PROTECTED]
> > > > > Thanks but I was looking more for ADO com object than ADSI or
ldap.
> > > > > For some strange reason it is very hard to locate any working
> scripts
> > > that
> > > > > use ADO to connect and search AD. Is there an issue with ADO and
> > python
> > > > > when connecting to AD?
> > > > > I have try to build one myself with no luck. I think my problem is
> > with
> > > > > adodb.command calls.
> > > > >
> > > > > Thanks for your response.
> > > > >
> > > > > "alex23" <[EMAIL PROTECTED]> wrote in message
> > > > > news:[EMAIL PROTECTED]
> > > > > > Heya,
> > > > > >
> > > > > > There are a couple of examples on the O'Reilly site. These two
are
> > > > > > taken from 'Active Directory Cookbook', the first uses a COM
> object
> > > > > > while the second uses a native LDAP module:
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>
http://www.rallenhome.com/books/adcookbook/src/18.6-rootdse_python_com.py.tx
> > > > > t
> > > > > >
> > > > >
> > > >
> > >
> >
>
http://www.rallenhome.com/books/adcookbook/src/18.6-rootdse_python_ldap.py.t
> > > > > xt
> > > > > >
> > > > > > This might give you a start.
> > > > > >
> > > > > > - alex23
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > == Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure
Usenet
> > > News==
> > > > http://www.newsfeeds.com The #1 Newsgroup Service in the World!
> 120,000+
> > > Newsgroups
> > > > = East and West-Coast Server Farms - Total Privacy via
Encryption
> > > =
> > >
> > >
> >
> >
> >
> > == Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet
> News==
> > http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
> Newsgroups
> > = East and West-Coast Server Farms - Total Privacy via Encryption
> =
>
>
--
http://mail.python.org/mailman/listinfo/python-list
Re: Seaching Active Directory via ADO
Do you know what this may mean?
C:\Documents and Settings\Administrator\Desktop\pytest>ADOSeach.py
Traceback (most recent call last):
File "C:\Documents and Settings\Administrator\Desktop\pytest\ADOSeach.py",
lin
e 6, in ?
rs,rc=c.Execute("""
File "", line 3, in Execute
File "C:\Python24\Lib\site-packages\win32com\client\dynamic.py", line 258,
in
_ApplyTypes_
result = self._oleobj_.InvokeTypes(*(dispid, LCID, wFlags, retType,
argTypes
) + args)
pywintypes.com_error: (-2147352567, 'Exception occurred.', (0, 'Provider',
'Tabl
e does not exist.', None, 1240640, -2147217865), None)
C:\Documents and Settings\Administrator\Desktop\pytest>
"Roger Upole" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> You could also accomplish the same thing using the
> Command object, but this way is usually more concise
> for plain Sql.
>
> Roger
>
> "LittlePython" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
> > I notice there is no adodb.command. This is not required?
> > Thx for the example!
> > "Roger Upole" <[EMAIL PROTECTED]> wrote in message
> > news:[EMAIL PROTECTED]
> > > Here's a short example that uses ADO to search for a
> > > user by wildcard.
> > >
> > > import win32com.client
> > > c = win32com.client.Dispatch("ADODB.Connection")
> > > c.Open("Provider=ADSDSOObject")
> > >
> > > rs,rc=c.Execute("""
> > > SELECT adspath, title, name
> > > From 'LDAP://DC=yourdomain, DC=COM'
> > > where objectClass='user' and name='Roger*'
> > > """)
> > >
> > > while not rs.EOF:
> > > for f in rs.Fields:
> > > print f.Name, f.Value
> > > rs.MoveNext()
> > >
> > > hth
> > > Roger
> > >
> > > "LittlePython" <[EMAIL PROTECTED]> wrote in message
> > > news:[EMAIL PROTECTED]
> > > > Thanks but I was looking more for ADO com object than ADSI or ldap.
> > > > For some strange reason it is very hard to locate any working
scripts
> > that
> > > > use ADO to connect and search AD. Is there an issue with ADO and
> python
> > > > when connecting to AD?
> > > > I have try to build one myself with no luck. I think my problem is
> with
> > > > adodb.command calls.
> > > >
> > > > Thanks for your response.
> > > >
> > > > "alex23" <[EMAIL PROTECTED]> wrote in message
> > > > news:[EMAIL PROTECTED]
> > > > > Heya,
> > > > >
> > > > > There are a couple of examples on the O'Reilly site. These two are
> > > > > taken from 'Active Directory Cookbook', the first uses a COM
object
> > > > > while the second uses a native LDAP module:
> > > > >
> > > > >
> > > >
> > >
> >
>
http://www.rallenhome.com/books/adcookbook/src/18.6-rootdse_python_com.py.tx
> > > > t
> > > > >
> > > >
> > >
> >
>
http://www.rallenhome.com/books/adcookbook/src/18.6-rootdse_python_ldap.py.t
> > > > xt
> > > > >
> > > > > This might give you a start.
> > > > >
> > > > > - alex23
> > > > >
> > > >
> > > >
> > >
> > >
> > >
> > > == Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet
> > News==
> > > http://www.newsfeeds.com The #1 Newsgroup Service in the World!
120,000+
> > Newsgroups
> > > = East and West-Coast Server Farms - Total Privacy via Encryption
> > =
> >
> >
>
>
>
> == Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet
News==
> http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
> = East and West-Coast Server Farms - Total Privacy via Encryption
=
--
http://mail.python.org/mailman/listinfo/python-list
Re: calculating on matrix indices
Colin J. Williams wrote: > Brian Blais wrote: >> In my attempt to learn python, migrating from matlab, I have the >> following problem. Here is what I want to do, (with the wrong syntax): >> >> from numpy import * >> >> t=arange(0,20,.1) >> x=zeros(len(t),'f') >> >> idx=(t>5)# <---this produces a Boolean array, probably not >> what you want. >> tau=5 >> x[idx]=exp(-t[idx]/tau) # <---this line is wrong (gives a TypeError) >> > What are you trying to do? It is most unlikely that you need Boolean > values in x[idx] > in this example, as in many that I would do in matlab, I want to replace part of a vector with values from another vector. In this case, I want x to be zero from t=0 to 5, and then have a value of exp(-t/tau) for t>5. I could do it with an explicit for-loop, but that would be both inefficient and unpython-like. For those who know matlab, what I am doing here is: t=0:.1:20; idx=find(t>5); tau=5; x=zeros(size(t)); x(idx)=exp(-t(idx)/tau) is that clearer? I am sure there is a nice method to do this in python, but I haven't found it in the python or numpy docs. thanks, bb -- - [EMAIL PROTECTED] http://web.bryant.edu/~bblais -- http://mail.python.org/mailman/listinfo/python-list
Re: Open Relay Test
D wrote: > Hi all .. how could one test to see if an open relay exists on a > specific email server? > I bet spammers would love someone to answer that question for them. You wouldn't be planning spam, by any chance? 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: getting the line just before or after a pattern searched
<[EMAIL PROTECTED]> wrote: > hi > > i have a file something like this > > abcdefgh > ijklmnopq > 12345678 > rstuvwxyz > . > . > . > 12345678 > . > > whenever i search the file and reach 12345678, how do i get the line > just above and below ( or more than 1 line above/below) the pattern > 12345678 and save to variables? thanks If the file's of reasonable size, read it all into memory into a list of lines with a .readlines method call, then loop with an index over said list and when you find your pattern at index i use i-1, i+1, and so on (just check that the resulting i+N or i-N is >=0 and http://mail.python.org/mailman/listinfo/python-list
Re: [Numpy-discussion] Re: calculating on matrix indices
Howdy,On 2/17/06, Brian Blais <[EMAIL PROTECTED]> wrote: Colin J. Williams wrote:> Brian Blais wrote:>> In my attempt to learn python, migrating from matlab, I have the>> following problem. Here is what I want to do, (with the wrong syntax):>> >> from numpy import * t=arange(0,20,.1)>> x=zeros(len(t),'f')This was the line causing the type error. t is type double (float64). 'f' makes x be type float32. That causes the assignment below to fail. Replacing that line with x=zeros(len(t),'d') should work. Or the zeros_like() that Travis suggested. idx=(t>5)# <---this produces a Boolean array, probably not what you want. >> tau=5>> x[idx]=exp(-t[idx]/tau) # <---this line is wrong (gives a TypeError)>>You could also use idx=where(t>5)In place of idx=(t>5) Although in this case it probably doesn't make much difference, where(expr) is more directly equivalent to matlab's find(expr).See http://www.scipy.org/Wiki/NumPy_for_Matlab_Users for more Matlab equivalents. And consider contributing your own, if you have some good ones that aren't there already.--bb -- http://mail.python.org/mailman/listinfo/python-list
Re: calculating on matrix indices
Brian Blais wrote: > Hello, > > In my attempt to learn python, migrating from matlab, I have the following > problem. > Here is what I want to do, (with the wrong syntax): > > from numpy import * > > t=arange(0,20,.1) > x=zeros(len(t),'f') > > idx=(t>5) > tau=5 > x[idx]=exp(-t[idx]/tau) # <---this line is wrong (gives a TypeError) Hi Brian, Just to let you know, you are more likely to get good answers by mailing [EMAIL PROTECTED] then posting to this list. The indexing technique you are using is actually fine. The trouble you are having is that t is a double-precision array (and thus so is exp(-t[idx]/tau) while x is a single-precision array. Compare: x.dtype.name t.dtype.name Because you are trying to store something with greater precision into an array with less precision you get a TypeError. So, either change x to be double precision: x = zeros(len(t), float) #the default Python float is doubleprecision or change t to be single precision: t = arange(0,20,.1,dtype=single) Good luck, -Travis -- http://mail.python.org/mailman/listinfo/python-list
ANN: Release of NumPy 0.9.5
NumPy is the successor to both Numeric and Numarray. It builds from and uses code from both. More information can be found at the following links http://numeric.scipy.org http://www.scipy.org http://sourceforge.net/project/showfiles.php?group_id=1369&package_id=175103 Highlights of Release: - Unicode arrays are now always UCS4 even on narrow Python builds - Many improvements and bugfixes to dtype objects - Improvements to numpy.distutils - Optimized dot function improved so copies are no longer made for transposed arrays - Many more bug-fixes Full release notes at http://sourceforge.net/project/shownotes.php?release_id=394206&group_id=1369 Best regards, -Travis Oliphant -- http://mail.python.org/mailman/listinfo/python-list
Re: embedding python in HTML
John Salerno: [Python alternative for PHP] >So to do this with Python, do I simply integrate it into the HTML as >above, with no extra steps? You'd need something like the PHP engine, that understands Python rather than PHP. I've used Cheetah: http://www.cheetahtemplate.org/ Our BDFL seems to prefer Django: http://www.artima.com/weblogs/viewpost.jsp?thread=146606 There's also PSP: http://www.ciobriefings.com/psp/ And many more: http://wiki.python.org/moin/WebProgramming -- René Pijlman -- http://mail.python.org/mailman/listinfo/python-list
Re: days since epoch
<[EMAIL PROTECTED]> wrote: > hi > how can i get the number of days since epoch using the time module? > or do i have to manually do the arithmetic? Try the datetime module -- better suited to computing days, than the time module, IMHO. Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: question about scope
John Salerno schrieb: > Here's a sentence from Learning Python: > > "Names not assigned a value in the function definition are assumed to be > enclosing scope locals (in an enclosing def), globals (in the enclosing > module's namespace) or built-in (in the predefined __builtin__ names > module Python provides." > > I have trouble reading this sentence. First, I don't understand if the > word 'enclosing' is a verb or an adjective. The whole flow of the > sentence seems convoluted. > > But my real question is this, which is related to the above: > > "Name references search at most four scopes: local, then enclosing > functions (if any), then global, then built-in." > > I understand what global and built-in are, and I thought I understood > the concept of local too, but when I got to this sentence (and the > previous sentence), I became confused about the first two scopes. What's > the difference between 'local' and 'enclosing functions'? I thought that > the only way to create a local namespace was if there *was* a function > definition, so now I'm confused by the apparent difference that the > authors are referring to. What's an example of a local scope without > having a function definition? Loops and if statements, perhaps? > Nested functions, I should think. Absolutely silly, but working example: >>> def outer(): arg_in = 2 def inner(): x = arg_in * 3 return x return inner() >>> outer() 6 Seen from the inside of "inner" x is local, arg_in is in the enclosing function. -- Dr. Sibylle Koczian Universitaetsbibliothek, Abt. Naturwiss. D-86135 Augsburg e-mail : [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: pythonic way of 'b = list(a); b.append(4)"
"szabi" <[EMAIL PROTECTED]> writes: > I have a list of three values and want to call a function with four > parameters. I would like > to write something like: > > a = [1, 2, 3] > f(*a, 4) f(*a+[4]) seems to work. -- http://mail.python.org/mailman/listinfo/python-list
Re: Copying zlib compression objects
No comments? I found a small bug in TarFile.snapshot() / restore() - they need to save and restore self.inodes as well. -- http://mail.python.org/mailman/listinfo/python-list
Re: looping over more than one list
> def lowest(s1,s2): > s = "" > for c1,c2 in [x for x in zip(s1,s2)]: > s += lowerChar(c1,c2) > return s > > but it's hardly any more elegant than using a loop counter, and I'm > guessing it's performance is a lot worse - I assume that the zip > operation is extra work? > > Iain Always look in itertools for stuff like this: http://docs.python.org/lib/itertools-functions.html#l2h-1392 for c1, c2 in itertools.izip(s1, s2): ... I haven't profiled it, but it makes sense that this would be fast. -- http://mail.python.org/mailman/listinfo/python-list
Mac OS X Installation Problem
Hi Everybody, 1) Does OS X have a thing like the Add/Remove Programs control panel on Windows XP? My Tiger system had Python v2.3.5 on it and I threw the files in the trash and installed v2.4.1, which is working fine as far as I can tell. However, when I type python at the command line, I get "command not found" so, 2) How do I get OS X to recognize python at the command line? Thanks, Matt -- http://mail.python.org/mailman/listinfo/python-list
Re: Databases and python
On Wed, 15 Feb 2006 23:37:31 -0800, Jonathan Gardner wrote: > I'm no expert in BDBs, but I have spent a fair amount of time working > with PostgreSQL and Oracle. It sounds like you need to put some > optimization into your algorithm and data representation. > > I would do pretty much like you are doing, except I would only have the > following relations: > > - word to word ID > - filename to filename ID > - word ID to filename ID I think I could ditch the "word ID to word" table, but I think I'll probably eventually need the "filename ID to filename" table, so when I pull a list of filename ID's by word I can get back the filenames. > You're going to want an index on pretty much every column in this > database. That's because you're going to lookup by any one of these > columns for the corresponding value. I do need some pretty heavy indexing. In fact, so far everything seems to be clicking along pretty well, except the part that I'm having trouble indexing - the per-word list of filenames. And that's because I already have one relation (word number -> filenames' numbers) that's complicating getting another relation for the list of filenames (just filename ID to '', but it'd be s much faster if I could nest the relations somehow). > I said I wasn't an expert in BDBs. But I do have some experience > building up large databases. In the first stage, you just accumulate the > data. Then you build the indexes only as you need them. Let's say you > are scanning your files. You won't need an index on the filename-to-ID > table. That's because you are just putting data in there. The word-to-ID > table needs an index on the word, but not ID (you're not looking up by > ID yet.) And the word ID-to-filename ID table doesn't need any indexes > yet either. So build up the data without the indexes. Once your scan is > complete, then build up the indexes you'll need for regular operation. > You can probably incrementally add data as you go. Interesting thought! I think I need to ponder this a bit more. I think the filename <-> filename number tables are pretty inexpensive, and the word <-> word number tables seem pretty inexpensive too. I think it's primarily the word number to filename numbers table that's messing up the performance really bad, and that's probably because the list of filename numbers is growing so large in some cases, and adding a filename to a word tends to be O(n), n==the number of filenames already on the word. May I ask: In what representation would you keep this word number to filename numbers relation stashed away until later, to build your indexes from more rapidly in a later pass? Are you thinking to keep them all in memory, or store them in a flat file somehow? > As far as filename ID and word IDs go, just use a counter to generate > the next number. If you use base255 as the number, you're really not > going to save much space. That's basically what I'm doing - incrementing a counter for each word, except I'm converting that counter to base255. The base255 representation of that counter brings the following benefits: 1) Converting a set of numbers to a string, without losing number boundaries, becomes just mapping them to base255, and string.joinfields'ing them. 2) Converting a string to a set of numbers, again without losing number boundaries, is just string.splitfields'ing them, and mapping them from base255 back to a list or set of numbers. 3) The numbers can be arbitrarily large, unlike with a, say, 4 or 8 byte fixed-length record representation > And your idea of hundreds of thousands of tables? Very bad. Don't do it. Sigh. I was afraid of that. :-S I'm thinking though... what if I were to use the current representation for words that don't appear in that many files, and a table for each word that has >= 1000 (or whatever threshold) filenames associated with it...? That should greatly cut down on the number of tables, while still giving the more efficient representation for the words that need it. Or not? -- http://mail.python.org/mailman/listinfo/python-list
Re: Installing python on lynxOS
Quoth "Bryce" <[EMAIL PROTECTED]>: | I'm trying to install python2.4.2 onto lynxOS 4.0.0. with gcc 2.95.3. | I was wondering if anyone who has done this before could give me some | pointers. | | I'm currently getting the following error when running make: | | gcc -o python Module/python.o libpython2.4.a -lsocket -lm | called2:ld returned 1 exit status | libpython2.4.a(pystate.o):In function 'PyThreadState_New': | Python2.4.2/pystate.c:191: undefined reference to | '_PyGILState_NoteThreadState' | called2:ld returned 1 exit status | | I checked pystate.c and the function _PyGILState_NoteThreadState is | defined in the file, so I'm a bit lost here. If you look about 50 lines up from there, you'll see that it's conditional on the WITH_THREAD preprocessor macro. If it's not defined because LynxOS doesn't have threads or at any rate there isn't a usable thread implementation among the existing thread_xyz.c options, you might be able to get past this problem by writing a trivial version of the function for the case where WITH_THREAD is not defined. I haven't looked at it, to know for sure what would be appropriate - maybe it was put inside WITH_THREAD in error, in the first place, for all I know. If you think you probably should be getting threads, then look at pyconfig.h to verify this. Donn Cave, [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Numarray - Using Integers Efficiently for Boolean Values
Below is the code to/from Boolean arrays and Unsigned integers. On my Pentium 4, functions such as "bitwise_and" are 32 times faster when run on 32-bit integers instead of the entire-byte-consuming-Boolean. Good luck all:-) uint32Mask = numarray.array([0x0001,0x0002,0x0004,0x0008, \ 0x0010,0x0020,0x0040,0x0080, \ 0x0100,0x0200,0x0400,0x0800, \ 0x1000,0x2000,0x4000,0x8000, \ 0x0001,0x0002,0x0004,0x0008, \ 0x0010,0x0020,0x0040,0x0080, \ 0x0100,0x0200,0x0400,0x0800, \ 0x1000,0x2000,0x4000,0x8000], numarray.UInt32) uint32MaskInner = numarray.copy.deepcopy(uint32Mask) uint32MaskInner.shape = [32,1] uint32MaskOuter = numarray.copy.deepcopy(uint32Mask) uint32MaskOuter.shape = [1,32] def BoolToUInt32(myArr): if myArr.size()%32 != 0: print "Size is: ", myArr.size() return numarray.matrixmultiply(numarray.reshape(myArr,[myArr.size()/32,32]),uint32MaskInner).flat def UInt32ToBool(myArr,destination=None): if destination == None: destination = numarray.zeros([myArr.size()*32],numarray.Bool) #return numarray.bitwise_and(numarray.reshape(myArr,[myArr.size(),1]),uint32MaskOuter).flat #else: destination.shape = [myArr.size(),32] numarray.bitwise_and(numarray.reshape(myArr,[myArr.size(),1]),uint32MaskOuter,destination) destination.shape = [destination.size()] return destination Test of code: >>> import numarray >>> gram.UInt32ToBool(ni) array([1, 0, 0, ..., 0, 0, 0], type=Bool) >>> numarray.all(numarray.equal(n,gram.UInt32ToBool(gram.BoolToUInt32(n 1 >>> n array([1, 0, 0, ..., 0, 0, 0], type=Bool) >>> n.shape (1024,) >>> numarray.all(numarray.equal(n,gram.UInt32ToBool(gram.BoolToUInt32(n 1 -- http://mail.python.org/mailman/listinfo/python-list
Re: multiple inheritance
That's perfect. thanks. -- http://mail.python.org/mailman/listinfo/python-list
Sendmail "ok" signal?
Hey. I looked at the Sendmail help and did not find a property where i can get an "ok" signal when the email is finally sent. I need something like that to show a "Processing, please stand by" screen when the server is sending an email, and when the email is out, another screen appears with an "Email sent" message. Do you know an alternative to the "ok" from the sendmail to do this? -- http://mail.python.org/mailman/listinfo/python-list
Re: %SystemDrive%
Atanas Banov wrote: > Bryan Olson wrote: > >>To get it with the \, you might use: >> >> os.path.abspath(os.environ['SYSTEMDRIVE']) > > > wrong! > the result is incorrect if the current directory is different from the > root. Oops, sorry. I should know better than to code from what I think I vaguely remember. -- --Bryan -- http://mail.python.org/mailman/listinfo/python-list
Open Relay Test
Hi all .. how could one test to see if an open relay exists on a specific email server? -- http://mail.python.org/mailman/listinfo/python-list
Re: embedding python in HTML
bruno at modulix wrote: > You've got to understand that Python is *not* a 'ServerPage' language > (-> php, asp, jsp etc) in itself. Your server can now run python, fine, > but *how* ? CGI ? FastCGI ? mod_python ? other ? (hint: it's probably > just plain old CGI...) So does that mean I need to have something further on the server? Or is this something I can do on my end? How do I find out what I need? -- http://mail.python.org/mailman/listinfo/python-list
pythonic way of 'b = list(a); b.append(4)"
Hi! I have a list of three values and want to call a function with four parameters. I would like to write something like: a = [1, 2, 3] f(*a, 4) This is syntactically wrong, so is there a function which appends a value to a list and returns the new value, so that I could write something like this: f(list(a).functional_append(4)) I can't modify 'a'. Thanks, Szabi -- http://mail.python.org/mailman/listinfo/python-list
Pyserial never read
Hello at all sorry for my english but i'm Italian. I use pyserial to communicate via rs232 with an extarnal device called smartmouse. I write the exact line that i want , but when i read i read only the echo ond not the other bytes. When i meke the same project with delphi i solve this problem with the call of the sleep. But in python it don't work. Have you got some ideas for solve my problem? Best Regards Luca -- http://mail.python.org/mailman/listinfo/python-list
getting the line just before or after a pattern searched
hi i have a file something like this abcdefgh ijklmnopq 12345678 rstuvwxyz . . . 12345678 . whenever i search the file and reach 12345678, how do i get the line just above and below ( or more than 1 line above/below) the pattern 12345678 and save to variables? thanks -- http://mail.python.org/mailman/listinfo/python-list
question about scope
Here's a sentence from Learning Python: "Names not assigned a value in the function definition are assumed to be enclosing scope locals (in an enclosing def), globals (in the enclosing module's namespace) or built-in (in the predefined __builtin__ names module Python provides." I have trouble reading this sentence. First, I don't understand if the word 'enclosing' is a verb or an adjective. The whole flow of the sentence seems convoluted. But my real question is this, which is related to the above: "Name references search at most four scopes: local, then enclosing functions (if any), then global, then built-in." I understand what global and built-in are, and I thought I understood the concept of local too, but when I got to this sentence (and the previous sentence), I became confused about the first two scopes. What's the difference between 'local' and 'enclosing functions'? I thought that the only way to create a local namespace was if there *was* a function definition, so now I'm confused by the apparent difference that the authors are referring to. What's an example of a local scope without having a function definition? Loops and if statements, perhaps? And feel free to dissect that first sentence up above, because I just don't get it. Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: Databases and python
On Thu, 16 Feb 2006 13:45:28 +, Bryan Olson wrote:
> Dan Stromberg wrote:
>> I've been putting a little bit of time into a file indexing engine
> [...]
>
>> So far, I've been taking the approach of using a single-table database
>> like gdbm or dbhash [...] and making each entry keyed by
>> a word, and under the word in the database is a null terminated list of
>> filenames (in http://dcs.nac.uci.edu/~strombrg/base255.html representation).
>>
> [...]
>> the program just isn't performing like I'd like it to.
> >
>> And I think it's because despite the caching and minimal representation
>> conversion, it's still just too slow converting linear lists to arrays
>> back and forth and back and forth.
>
> I think I follow. The straightforward method of building the
> list of files associated with a word is order n**2 time. On each
> new entry, you look up the entire string, append one file-id to
> it, and write the new version back.
Yes, essentially, with the twist that the most recently used words are
kept cached in memory, so they don't have to be converted from string to
list and back to string every time a filename is added to a word.
>> So this leads me to wonder - is there a python database interface that
>> would allow me to define a -lot- of tables? Like, each word becomes a
>> table, and then the fields in that table are just the filenames that
>> contained that word. That way adding filenames to a word shouldn't bog
>> down much at all.
>
> Well, you could use simple files instead of fancy database tables.
That's an interesting thought. Perhaps especially if australopithecine
were saved in a filename like:
~/indices/au/st/ra/lo/pi/th/ec/in/e
> Below is a demo of an alternate technique that uses bsddb B-Trees,
> and puts both the word and the file-id in the key. I don't know
> how efficient it is for real data, but at least the time won't grow
> as Theta(n**2).
Perhaps I'm missing something, but is it not roughly O(1) for
individual insertions, but O(n*m) (n == number of files, m == number of
words) for lookups?
> --Bryan
>
>
>
> import bsddb
> import urllib
>
>
> def add_words_from_file(index, fname, word_iterator):
> """ Pass the open-for-write bsddb B-Tree, a filename, and a list
> (or any interable) of the words in the file.
> """
> fname = urllib.quote_plus(fname)
> s = set()
> for word in word_iterator:
> if word not in s:
> s.update(word)
> key = '%s %s' % (urllib.quote_plus(word), fname)
> index[key] = ''
> index.sync()
>
>
> def lookup(index, word):
> """ Pass the B-Tree (as built with add_words_from_file) and a
> word to look up. Returns list of files containing the word.
> """
> word = urllib.quote_plus(word)
> fname_list = []
> try:
> current = index.set_location(word)
> while True:
> (key, _) = current
> (w, fname) = key.split()
> if w != word:
> break
> fname_list.append(urllib.unquote_plus(fname))
> current = index.next()
> except KeyError:
> pass
> return fname_list
>
>
> def test():
> index = bsddb.btopen('junktest.bdb', 'n')
> data =[
> ('bryfile.txt', 'nor heed the rumble of a distant drum'),
> ('junkfile.txt', 'this is the beast, the beast so sly'),
> ('word file.txt', 'is this the way it always is here in Baltimore')
> ]
> for (fname, text) in data:
> words = text.split()
> add_words_from_file(index, fname, words)
>
> for word in ['is', 'the', 'heed', 'this', 'way']:
> print '"%s" is in files: %s' % (word, lookup(index, word))
>
> test()
--
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Re: Seaching Active Directory via ADO
You could also accomplish the same thing using the
Command object, but this way is usually more concise
for plain Sql.
Roger
"LittlePython" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> I notice there is no adodb.command. This is not required?
> Thx for the example!
> "Roger Upole" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
> > Here's a short example that uses ADO to search for a
> > user by wildcard.
> >
> > import win32com.client
> > c = win32com.client.Dispatch("ADODB.Connection")
> > c.Open("Provider=ADSDSOObject")
> >
> > rs,rc=c.Execute("""
> > SELECT adspath, title, name
> > From 'LDAP://DC=yourdomain, DC=COM'
> > where objectClass='user' and name='Roger*'
> > """)
> >
> > while not rs.EOF:
> > for f in rs.Fields:
> > print f.Name, f.Value
> > rs.MoveNext()
> >
> > hth
> > Roger
> >
> > "LittlePython" <[EMAIL PROTECTED]> wrote in message
> > news:[EMAIL PROTECTED]
> > > Thanks but I was looking more for ADO com object than ADSI or ldap.
> > > For some strange reason it is very hard to locate any working scripts
> that
> > > use ADO to connect and search AD. Is there an issue with ADO and
python
> > > when connecting to AD?
> > > I have try to build one myself with no luck. I think my problem is
with
> > > adodb.command calls.
> > >
> > > Thanks for your response.
> > >
> > > "alex23" <[EMAIL PROTECTED]> wrote in message
> > > news:[EMAIL PROTECTED]
> > > > Heya,
> > > >
> > > > There are a couple of examples on the O'Reilly site. These two are
> > > > taken from 'Active Directory Cookbook', the first uses a COM object
> > > > while the second uses a native LDAP module:
> > > >
> > > >
> > >
> >
>
http://www.rallenhome.com/books/adcookbook/src/18.6-rootdse_python_com.py.tx
> > > t
> > > >
> > >
> >
>
http://www.rallenhome.com/books/adcookbook/src/18.6-rootdse_python_ldap.py.t
> > > xt
> > > >
> > > > This might give you a start.
> > > >
> > > > - alex23
> > > >
> > >
> > >
> >
> >
> >
> > == Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet
> News==
> > http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
> Newsgroups
> > = East and West-Coast Server Farms - Total Privacy via Encryption
> =
>
>
== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet
News==
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
= East and West-Coast Server Farms - Total Privacy via Encryption =
--
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Re: Merging two lists of data (Pythonic way)
You might consider writing two classes to represent the values in list1 and list2. It might be more Pythonic than sloshing around all of those lists and dictionaries. But as it is, it looks like you want to find matching pairs of lists and dictionaries from list1 and list2, respectively: # index dictionaries from LIST2 by 'code' element. # (assumption: no two dicts have the same "code" value) lookup_table = dict( [(d['code'], d) for list in LIST2] ) # iterate over LIST1, matching list1 elements with corresponding list2 elements pairs = [( L, lookup_table[L[0]]) for L in LIST1 if L[0] in lookup_table] # make whatever kind of modifications you want for list_item, dictionary_item in pairs: dictionary_item['VERIFIED'] = list_item[2] # or something And- If you're using Python 2.4, you can get more efficient memory usage out of this by using generator expressions instead of list comprehensions. -- http://mail.python.org/mailman/listinfo/python-list
Queue.Queue()
what happens behind the scenes when i create a Queue.Queue() without specifying a maxsize? does a block of space gets allocated initially then dynamically "expanded" as needed? if so, what is the default size of the initial space? is it always better to specify a big enough maxsize initially for efficiency purposes, or does it matter much? Thanks in advance for any help/detail __Do You Yahoo!?Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- http://mail.python.org/mailman/listinfo/python-list
Re: calculating on matrix indices
Brian Blais wrote: > Hello, > > In my attempt to learn python, migrating from matlab, I have the > following problem. Here is what I want to do, (with the wrong syntax): > > from numpy import * > > t=arange(0,20,.1) > x=zeros(len(t),'f') > > idx=(t>5)# <---this produces a Boolean array, probably not > what you want. > tau=5 > x[idx]=exp(-t[idx]/tau) # <---this line is wrong (gives a TypeError) > > #-- > > what is the best way to replace the wrong line with something that > works: replace all of the values of x at the indices idx with > exp(-t/tau) for values of t at indices idx? > > I do this all the time in matlab scripts, but I don't know that the > pythonic preferred method is. > > > > thanks, > > bb > > Brian, What are you trying to do? It is most unlikely that you need Boolean values in x[idx] Colin W. -- http://mail.python.org/mailman/listinfo/python-list
calculating on matrix indices
Hello, In my attempt to learn python, migrating from matlab, I have the following problem. Here is what I want to do, (with the wrong syntax): from numpy import * t=arange(0,20,.1) x=zeros(len(t),'f') idx=(t>5) tau=5 x[idx]=exp(-t[idx]/tau) # <---this line is wrong (gives a TypeError) #-- what is the best way to replace the wrong line with something that works: replace all of the values of x at the indices idx with exp(-t/tau) for values of t at indices idx? I do this all the time in matlab scripts, but I don't know that the pythonic preferred method is. thanks, bb -- - [EMAIL PROTECTED] http://web.bryant.edu/~bblais -- http://mail.python.org/mailman/listinfo/python-list
Re: question about scope
John Salerno wrote: > I understand what global and built-in are, and I thought I understood > the concept of local too, but when I got to this sentence (and the > previous sentence), I became confused about the first two scopes. What's > the difference between 'local' and 'enclosing functions'? I guess maybe I jumped the gun. Here's some stuff later in the chapter that I think explains it for me: -- Note that the second 'E' scope lookup layer -- enclosing defs or lambdas -- technically can correspond to more than one lookup layer. It only comes into play when you nest functions within functions.* * The scope lookup rule was known as the "LGB" rule in the first edition of this book. The enclosing def layer was added later in Python, to obviate the task of passing in enclosing scope names explicitly -- something usually of marginal interest to Python beginners. -- -- http://mail.python.org/mailman/listinfo/python-list
Installing python on lynxOS
I'm trying to install python2.4.2 onto lynxOS 4.0.0. with gcc 2.95.3. I was wondering if anyone who has done this before could give me some pointers. I'm currently getting the following error when running make: gcc -o python Module/python.o libpython2.4.a -lsocket -lm called2:ld returned 1 exit status libpython2.4.a(pystate.o):In function 'PyThreadState_New': Python2.4.2/pystate.c:191: undefined reference to '_PyGILState_NoteThreadState' called2:ld returned 1 exit status I checked pystate.c and the function _PyGILState_NoteThreadState is defined in the file, so I'm a bit lost here. -- Bryce -- http://mail.python.org/mailman/listinfo/python-list
Seaching Active Directory via ADO
I am have trouble finding a simple working example of using ADO to search Active Directory. I am hoping someone could point me to a generic working script that connects to AD and pulls up a recordset to help me get started into the right direction in learning ADO, ADSI on Python. -- http://mail.python.org/mailman/listinfo/python-list
Re: Merging two lists of data (Pythonic way)
"SMB" <[EMAIL PROTECTED]> writes: > What I am doing is looking for a pythonic way to parse the LIST2 "code" > values and make appropriate changes to to each dictionary if the "code" > value is the first element of a list in LIST1. > > The final result may look like this given that the change is adding a new > key/value of "VERIFIED"/1 for the matches. Untested: from sets import Set vvals = Set(a[0] for a in LIST1)# get all the List1 first elt. values for d in LIST2: if d['code'] in vvals: d['VERIFIED'] = 1 > I know I could do this with two for loops, but am looking for a better > solution maybe involving list comprehension. I think if list1 is potentially long, the main thing is to avoid n**2 running time, which means use a set or dict to do the lookups, like above. -- http://mail.python.org/mailman/listinfo/python-list
Re: question about scope
On Thu, 16 Feb 2006 15:18:29 +, John Salerno wrote: > What's an example of a local scope without > having a function definition? Loops and if statements, perhaps? List comprehensions: [2*x+1 for x in range(50)] Lambdas: map(lambda y: y-2, [1,2,4,8,16,32]) At the moment the x in list comprehensions are exported to the rest of the local scope, but that (mis)feature is officially going to be removed in future versions of Python. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Merging two lists of data (Pythonic way)
"Jonathan Gardner" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > codes = map(lambda x: x[0], list1) > for d in list2: > if d['code'] in codes: >d['VERIFIED'] = 1 > > Is this what you were looking for? > That is exactly what I was looking for. I will have to take a look at map. Thank you very much -- http://mail.python.org/mailman/listinfo/python-list
Re: embedding python in HTML
John Salerno wrote:
> Rene Pijlman wrote:
>
>> John Salerno:
>> [Python alternative for PHP]
>>
>>> So to do this with Python, do I simply integrate it into the HTML as
>>> above, with no extra steps?
>>
>>
>> You'd need something like the PHP engine, that understands Python rather
>> than PHP.
>
>
> My web server can run Python, fortunately. Now that they've turned it on
> for me, I wanted to try it out, but I didn't know how to go about
> writing a bit of code to stick into an HTML file.
You've got to understand that Python is *not* a 'ServerPage' language
(-> php, asp, jsp etc) in itself. Your server can now run python, fine,
but *how* ? CGI ? FastCGI ? mod_python ? other ? (hint: it's probably
just plain old CGI...)
--
bruno desthuilliers
python -c "print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in '[EMAIL PROTECTED]'.split('@')])"
--
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Re: Safe Python Execution
Jean-Paul Calderone wrote:
> On Thu, 16 Feb 2006 07:59:03 -0800, Alex Martelli <[EMAIL PROTECTED]> wrote:
> >Graham <[EMAIL PROTECTED]> wrote:
> >
> >> I've been messing around with trying to get a small sandbox like
> >> environment where i could execute python code in a "safe" way.
> >> Basically what the old restricted execution module attempted to do.
> >> I've written a small amount of code to get custom interpreter running,
> >> but i'm not really sure if its safe.
> >>
> >> The way i'm controlling functionality is with some games and exec, so
> >> if 'code' was the text code you wanted to execute i run:
> >>
> >> exec code in {'__builtins__':None"}
> >>
> >> obviously this doesn't give you much to play with, but it does remove
> >> file access and importing as far as i can tell. Can anyone think of a
> >> hack around this? I assume if it was this easy it would be a module
> >> already but i figured i would ask.
> >
> >I suggest compiling the code and examining the names used in the code
> >object (co_names attribute of the code object which compile returns) --
> >refuse to execute the code if it mentions, defines or uses any special
> >name (starting and ending with two underscores). That, plus removing
> >almost all builtins as you do here, should be a good start.
>
> A good start, perhaps, but still in need of a good finish.
>
> """
> exec 'print ' + ''.join(map(chr, [
> 95, 95, 98, 117, 105, 108, 116, 105, 110, 115, 95, 95]))
> """
>
> You can come up with a long list of restrictions to impose, and maybe that
> will be good enough. But making it /perfect/ is a Herculean task, as is
> maintaining it as new Python releases are made, and auditing it every time
> you add a new piece of code to your system.
>
What about what's in zope, :
http://svn.zope.org/Zope3/trunk/src/zope/security/untrustedinterpreter.txt?view=auto
--
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Re: Is empty string cached?
> A few comments (which I hope are correct, but which I hope you will read > then mostly ignore since you probably shouldn't be designing based on > this stuff anyway): Thanks for the info Peter. My original question wasn't due to any observed performance problems. I was just being curious :) -Farshid -- http://mail.python.org/mailman/listinfo/python-list
Re: pythonic way of 'b = list(a); b.append(4)"
The question was perfectly answered by Heiko Wundram: f(*(a+[4])) I know python is not a lawnmower but a programming language. I can solve a lot of problems, but I prefer short, clear and nice solutions to long and/or too powerful ones. So, my problem with my solution (b = list(a); b.append(4)) was the same as with the others' involving functions. Actually what I missed is the fact that the + operator works fine with lists... With '+' I can solve everything. Ok, _almost_ everything :) Thanks for everybody! Szabi -- http://mail.python.org/mailman/listinfo/python-list
mod_python and open HTTP connection
Hello, I'm think about using mod_python for a project but I need to make sure: Does mod_python time out after a minute ? (I hope not). If I leave an HTTP connection open so that the content keeps loading inside the browser window indefinately, and if I close the browser window, the mod_python process is terminated, right? Thanks, -- Charles. Desenvolvimento e criação de sites: www.auriance.com Hospedagem de sites e servidores dedicados: www.auriance.net -- http://mail.python.org/mailman/listinfo/python-list
Re: looping over more than one list
> def lowest(s1,s2): > s = "" > for i in xrange(len(s1)): > s += lowerChar(s1[i],s2[i]) > return s > > this seems unpythonic, compared to something like: > > def lowest(s1,s2): > s = "" > for c1,c2 in s1,s2: > s += lowerChar(c1,c2) > return s If I understand correctly, something like for c1,c2 in zip(s1,s2): is what you're looking for. It will gracefully stop when it reaches the end of the shortest input. (in your indexed example above, if s2 is shorter than s1, it will likely throw an out-of-bounds exception) For your example, I'd use def lowest(s1,s2): return ''.join([lowerChar(c1,c2) for c1,c2 in zip(s1,s2)]) which seems to do what you describe (I understand that appending to strings is an inefficient operation and is better done with a join like this) -tkc -- http://mail.python.org/mailman/listinfo/python-list
Re: looping over more than one list
Iain King <[EMAIL PROTECTED]> wrote: ... > This works: > > def lowest(s1,s2): > s = "" > for c1,c2 in [x for x in zip(s1,s2)]: > s += lowerChar(c1,c2) > return s > > but it's hardly any more elegant than using a loop counter, and I'm > guessing it's performance is a lot worse - I assume that the zip > operation is extra work? 1. [x for x in whateverlist] just doesn't make sense! If you need a copy of whateverlist, just use list(whateverlist). When you don't need a copy, like here, just use whateverlist. I.e., loop this way: for c1, c2 in zip(s1, s2): 2. performance is destroyed by building up a big list with a += of many small pieces. Use cStringIO (some people prefer it for style reasons) or (what most people do) ''.join a list where you've accumulated the results. 3. this case is ideal for build-in function map. The body of the function could be just one statement: return ''.join(map(lowerChar, s1, s2)) This probably gives best performance. Also consider a genexp and avoiding the unpacking/repacking a la: return ''.join(lowerChar(*cs) for cs in zip(s1, s2)) or better: import itertools and then return ''.join(lowerChar(*cs) for cs in itertools.izip(s1, s2)) or return ''.join(itertools.imap(lowerChar, s1, s2)) If you care about performance, use module timeit from the standard library to measure cases of interest. If you don't (not especially) then the first solution looks neat, elegant, readable, and concise. But never build up substantial strings with a loop of += of small strings: that's O(N squared) and will MAKE you care about performance even where you otherwise wouldn't!-) Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: web crawler in python or C?
On Wed, 15 Feb 2006 21:56:52 -0800, abhinav wrote: > Hi guys.I have to implement a topical crawler as a part of my > project.What language should i implement > C or Python?Python though has fast development cycle but my concern is > speed also.I want to strke a balance between development speed and > crawler speed.Since Python is an interpreted language it is rather > slow. Python is no more interpreted than Java. Like Java, it is compiled to byte-code. Unlike Java, it doesn't take three weeks to start the runtime environment. (Okay, maybe it just *seems* like three weeks.) The nice clean distinctions between "compiled" and "interpreted" languages haven't existed in most serious programming languages for a decade or more. In these days of tokenizers and byte-code compilers and processors emulating other processors, the difference is more of degree than kind. It is true that standard Python doesn't compile to platform dependent machine code, but that is rarely an issue since the bottleneck for most applications is I/O or human interaction, not language speed. And for those cases where it is a problem, there are solutions, like Psycho. After all, it is almost never true that your code must run as fast as physically possible. That's called "over-engineering". It just needs to run as fast as needed, that's all. And that's a much simpler problem to solve cheaply. > The crawler which will be working on huge set of pages should be > as fast as possible. Web crawler performance is almost certainly going to be I/O bound. Sounds to me like you are guilty of trying to optimize your code before even writing a single line of code. What you call "huge" may not be huge to your computer. Have you tried? The great thing about Python is you can write a prototype in maybe a tenth the time it would take you to do the same thing in C. Instead of trying to guess what the performance bottlenecks will be, you can write your code and profile it and find the bottlenecks with accuracy. > One possible implementation would be implementing > partly in C and partly in Python so that i can have best of both > worlds. Sure you can do that, if you need to. > But i don't know to approach about it.Can anyone guide me on > what part should i implement in C and what should be in Python? Yes. Write it all in Python. Test it, debug it, get it working. Once it is working, and not before, rigorously profile it. You may find it is fast enough. If it is not fast enough, find the bottlenecks. Replace them with better algorithms. We had an example on comp.lang.python just a day or two ago where a function which was taking hours to complete was re-written with a better algorithm which took only seconds. And still in Python. If it is still too slow after using better algorithms, or if there are no better algorithms, then and only then re-write those bottlenecks in C for speed. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: question about scope
John Salerno wrote: > But my real question is this, which is related to the above: > > "Name references search at most four scopes: local, then enclosing > functions (if any), then global, then built-in." > > I understand what global and built-in are, and I thought I understood > the concept of local too, but when I got to this sentence (and the > previous sentence), I became confused about the first two scopes. What's > the difference between 'local' and 'enclosing functions'? consider a nested function: var1 = "global" def outer(): var2 = "enclosing" def inner(): var3 = "local" print var1, var2, var3 inner() # call it inside "inner", var1 refers to the global variable, var2 to the enclosing variable (which is local to "outer"), and var3 to the local variable. "enclosing scope locals" are also called "free variables". -- http://mail.python.org/mailman/listinfo/python-list
Re: pythonic way of 'b = list(a); b.append(4)"
szabi wrote: > I have a list of three values and want to call a function with four > parameters. I would like > to write something like: > > a = [1, 2, 3] > f(*a, 4) > > This is syntactically wrong, so is there a function which appends a > value to a list and > returns the new value, so that I could write something like this: > > f(list(a).functional_append(4)) > > I can't modify 'a'. Two more options: if you know the name of the function's fourth parameter you can mix keyword and positional arguments >>> def f(a, b, c, d): ... return "f(a=%r, b=%r, c=%r, d=%r)" % (a, b, c, d) ... >>> a = [1, 2, 3] >>> f(d=42, *a) 'f(a=1, b=2, c=3, d=42)' or you can use partial function application: >>> def partial(f, *left): ... def w(*right): ... return f(*left+right) ... return w ... >>> partial(f, *a)(42) 'f(a=1, b=2, c=3, d=42)' A generalized version of partial() will become part of the standard library in Python 2.5. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: is socket thread safe?
Jean-Paul Calderone wrote: > On Wed, 15 Feb 2006 12:59:03 -0800, "Carl J. Van Arsdall" <[EMAIL PROTECTED]> > wrote: > >> Steve Horsley wrote: >> >>> [EMAIL PROTECTED] wrote: >>> >>> thread1: while 1: buf = s.read() process(buf) thread2: while 1: buf = getdata() s.write(buf) >>> It is safe, but watch out for this gotcha: If thread B calls >>> s.close() while thread A is blocked in s.read(), thread A will >>> never return from the read. My preferred solution is to set >>> socket timeout to a few seconds, and loop checking a status flag >>> so I know when to quit. >>> >>> >>> >> I think a better thing would be to use something like a condition object >> to tie the two threads together and not use any polling loops. >> >> i.e. consumer goes to sleep while data buffer is empty, producer >> produces and signals condition object, consumer wakes up and consumes. >> > > What makes you think process isn't implemented to notify a condition, and > getdata isn't implemented to wait on one? :) > > I think it was the "loop checking status flag" comment that threw me off *shrug* 8) -carl -- Carl J. Van Arsdall [EMAIL PROTECTED] Build and Release MontaVista Software -- http://mail.python.org/mailman/listinfo/python-list
Re: Some general questions about using "stdin","stdout"....
asdsd sir wrote:
> Hi!I'm new in Python and i'd like to ask some general questions about
> stdin,stdout...
>
> Firstly...
>
> if we type like something like :
>cat "file.txt"|python somefile.py
>
> #somefile.py
> import sys
> text=sys.stdin.read()
>
>
> ...then "sys.stdin.read()" will read from "cat"s stdout...
> However,if i type inside a program,something like
>
> #someprog.py
> import sys
>print "hello"|sys.stdin.read()
>
> .the screen hangs..why is that?isn't the same situation as "cat"?
Obviously not... The stdin is a read-only file that you can read from the
data that is passed via a pipe to your application. You did tha piping by
using
cat "file.txt" | python somefile.py
That establihes the pipe between cat's stdout(!) and python's stdin. That's
the reason that | is called "pipe" or "pipe-operator" in the SHELL(!)
print "hello"|sys.stdin.read()
OTH is inside python, and | is not the pipe-operator, but the binary
or-operator. Consider this:
>>> print 1 | 2
3
But:
>>> print "hello" | "some other string"
Traceback (most recent call last):
File "", line 1, in ?
TypeError: unsupported operand type(s) for |: 'str' and 'str'
So you don't write something to stdin by that. Instead it waits endlessly,
trying to read something that is piped to it from the outside. But if that
was the case, it would puke on you with the above error message.
> in addition to this...
> Why can't i "write" to the stdin?
> Isn't it being used as a file object like all the others?
> for example
> sys.stdin.close() or
> open('sys.stdin','w+') or
> sys.stdin.write("something") etc... don't work...
Because it is defined that way. I suggest you read up on unix piping to
grasp the concepts behind it - python only follows these.
Diez
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Re: pythonic way of 'b = list(a); b.append(4)"
szabi wrote: > a = [1, 2, 3] > f(*a, 4) f(*(a+[4])) --- Heiko. -- http://mail.python.org/mailman/listinfo/python-list
Re: Determing whether two ranges overlap
Robin Haswell wrote: > I was wondering if you could give me a hand with something. If I have two > tuples that define a range, eg: (10, 20), (15, 30), I need to determine > whether the ranges overlap each other. The algo needs to catch: > > (10, 20) (15, 25) > (15, 25) (10, 20) > (10, 25) (15, 20) > and > (15, 20) (10, 25) > > I can think of lots of ways to do this but it's in a tight loop so I need > it to be as efficient as possible. Any help welcome :-) how about: def overlap(a, b): return a[1] > b[0] and a[0] < b[1] -- http://mail.python.org/mailman/listinfo/python-list
Re: Some general questions about using "stdin","stdout"....
Hello.
If you're new to Python, then input/output isn't the best place to
start. Begin with the tutorial:
http://docs.python.org/tut/tut.html
Other documentation is also linked to from there.
However, I will briefly answer your questions.
> print "hello"|sys.stdin.read()
In Python the | operator has a different meaning than in a shell. In
Python it means "bitwise or":
>>> print 5 | 9
13
> Why can't i "write" to the stdin?
There may be some contorted way to do that under Unix, but it's not a
good idea. You can pipe input to your program from a shell (as you've
already done), but it's not a good idea to redirect input from within
your program.
You can accomplish the same thing like this:
if i_want_to_redirect_input:
my_input_source = open('file.txt')
else:
my_input_source = sys.stdin
# Now read from my_input_source instead of stdin.
--
They had a big meeting, drank some beer and had some pizza and
decided 'A' would be 65.
- Jim Greenly, professor at Georgia Institute of Technology
--
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Re: How to run shell commands within python
In article <[EMAIL PROTECTED]>, "Fredrik Lundh" <[EMAIL PROTECTED]> wrote: > (also note that most trivial shell commands are better done in > python. most uses of cat, for example, can be trivially emulated > with one or two lines of python...) Though the knowledge required to do this may be more trivial for some of us than others! "cat" probably doesn't have much going for it that a naive implementation would miss - some versions will recreate "holes", but most applications will never miss this. You can replace "mv" with os.rename() if you don't care that it will fail when the destination is on a different filesystem. Etc. Donn Cave, [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: is socket thread safe?
Bryan Olson wrote: > Carl J. Van Arsdall wrote: > >> Steve Horsley wrote: >> >> >>> [EMAIL PROTECTED] wrote: >>> >>> >>> thread1: while 1: buf = s.read() process(buf) thread2: while 1: buf = getdata() s.write(buf) >>> It is safe, but watch out for this gotcha: If thread B calls s.close() >>> while thread A is blocked in s.read(), thread A will never return from >>> the read. My preferred solution is to set socket timeout to a few >>> seconds, and loop checking a status flag so I know when to quit. >>> > > Certainly one needs timeouts to avoid hanging should the remote > side stop. Sockets don't have a read() method, and hanging on > recv() doesn't seem to have anything to do with close(). > > I didn't find any definitive doc, so I tested using Python > sockets on Linux (Debian/Ubuntu current) and WinXP. A recv() > started before the close() will block/return just as if > close() were never called. The close() neither triggers recv() > to abort, nor prevents it from receiving data and detecting > shutdown. > > > >> I think a better thing would be to use something like a condition object >> to tie the two threads together and not use any polling loops. >> >> i.e. consumer goes to sleep while data buffer is empty, producer >> produces and signals condition object, consumer wakes up and consumes. >> > > I can infer two producer-consumer relationships from the example, > but they don't allow a condition object; the writer's consumer and > the reader's producer are on the remote end of the socket. The > socket will already handle the blocking and wake-up. > > >> To take this a step further, you have a status flag that is set to >> something like QUIT or CONSUME and when the condition is triggered wake >> up, then examine the status flag to determine if the consumer should >> then quit, consume, or whatever else you'd want your consumer thread to do. >> > > What problem are you trying to solve? Normal socket sending, receiving, > and shutdown discipline work fine. When the writer is done writing, it > should call sock.shutdown(socket.SHUT_WR). When the reader gets zero > bytes from recv(nonzero), that means the remote end has finished > writing, so the reader may call sock.shutdown(socket.SHUT_RD). > Doh! I read the word threads and got carried away not even realizing sockets. Well, looks like today i'll just have to remember to drink my coffee :-D -c -- Carl J. Van Arsdall [EMAIL PROTECTED] Build and Release MontaVista Software -- http://mail.python.org/mailman/listinfo/python-list
RE: Determing whether two ranges overlap
[Robin Haswell] | I was wondering if you could give me a hand with something. | If I have two | tuples that define a range, eg: (10, 20), (15, 30), I need to | determine | whether the ranges overlap each other. The algo needs to catch: | | (10, 20) (15, 25) | (15, 25) (10, 20) | (10, 25) (15, 20) | and | (15, 20) (10, 25) | | I can think of lots of ways to do this but it's in a tight | loop so I need | it to be as efficient as possible. Any help welcome :-) Don't know about efficient, but: x = 10, 20 y = 15, 25 (x[0] <= y[1]) and (x[1] >= y[0]) 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: question about scope
John Salerno wrote: [snip..] > > Thanks guys. It seems like nested functions were what the authors had in > mind, so that makes a lot more sense now. > > But as far as ifs and loops, is there such a thing as scope in them? For > example, if I assign a variable within an if statement, is it usable > anywhere else? Defining a variable in a loop, or within an 'if block' doesn't change scope, so the variables are useable in the same way as variables outside the loop. Obviously if you define them within an if block, they may *not* be defined, so using them could raise a NameError. if False: test = 'something' print test All the best, Fuzzyman http://www.voidspace.org.uk/python/index.shtml -- http://mail.python.org/mailman/listinfo/python-list
Re: Determing whether two ranges overlap
On Thu, 16 Feb 2006 15:22:15 +, Robin Haswell wrote: > Hey guys > > I was wondering if you could give me a hand with something. If I have two > tuples that define a range, eg: (10, 20), (15, 30), I need to determine > whether the ranges overlap each other. The algo needs to catch: > > (10, 20) (15, 25) > (15, 25) (10, 20) > (10, 25) (15, 20) > and > (15, 20) (10, 25) What do you mean "catch"? Do you expect the algorithm to recognise these combinations as special and return something different? I'm going to assume that there are no magic values that need to be caught, because I don't know what that means, and just proceed as if the task is to compare two tuples of the form (x1, x2) where x1 <= x2. # warning: untested! def isoverlap((x1,x2), (y1,y2)): """Given two numeric ranges, returns a flag True or False indicating whether they overlap. Assumes that the ranges are ordered (smallest,largest). If that assumption is wrong, incorrect results may occur.""" # Fully overlapping cases: # x1 <= y1 <= y2 <= x2 # y1 <= x1 <= x2 <= y2 # Partially overlapping cases: # x1 <= y1 <= x2 <= y2 # y1 <= x1 <= y2 <= x2 # Non-overlapping cases: # x1 <= x2 < y1 <= y2 # y1 <= y2 < x1 <= x2 return not (x2 < y1 or y2 < x1) > I can think of lots of ways to do this but it's in a tight loop so I > need it to be as efficient as possible. "Efficient as possible" in what way? Least memory used? Smallest number of bytes of source code? Fastest performance? Assuming you need fastest performance, the general method to do that is to write it in hand-tuned assembly language, taking care to use all the tricks to optimize it for the particular CPU you are running on. If you can find a way to push the processing into any high-end graphics processors you might have, that typically will speed it up even more. It is still, sometimes, possible for the best assembly programmers to just barely outperform optimizing C compilers, or so I'm told. If you are willing to set your sights just a little lower, and rather than aiming for the absolute fastest code possible, settle for code which is fast enough, the usual technique is to stick to Python. Write different functions implementing the various methods you can think of, and then time them with the timeit module. Pick the fastest. Is it fast enough that performance is satisfactory? If so, then you are done. Here is a technique that may speed your code up a little: it is quicker to find local variables than global. So, instead of this: def main(): ... code here ... while condition: flag = isoverlap(t1, t2) ... code ... you can gain a little speed by making a local reference to the function: def main(): ... code here ... iso = isoverlap # make a local reference for speed while condition: flag = iso(t1, t2) ... code ... If your code is still too slow, you might speed it up with Psycho, or you may need to write a C extension. Either way, you won't know if the code is fast enough until you actually run it. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Safe Python Execution
Graham <[EMAIL PROTECTED]> wrote:
> I've been messing around with trying to get a small sandbox like
> environment where i could execute python code in a "safe" way.
> Basically what the old restricted execution module attempted to do.
> I've written a small amount of code to get custom interpreter running,
> but i'm not really sure if its safe.
>
> The way i'm controlling functionality is with some games and exec, so
> if 'code' was the text code you wanted to execute i run:
>
> exec code in {'__builtins__':None"}
>
> obviously this doesn't give you much to play with, but it does remove
> file access and importing as far as i can tell. Can anyone think of a
> hack around this? I assume if it was this easy it would be a module
> already but i figured i would ask.
I suggest compiling the code and examining the names used in the code
object (co_names attribute of the code object which compile returns) --
refuse to execute the code if it mentions, defines or uses any special
name (starting and ending with two underscores). That, plus removing
almost all builtins as you do here, should be a good start.
Alex
--
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Determing whether two ranges overlap
Hey guys I was wondering if you could give me a hand with something. If I have two tuples that define a range, eg: (10, 20), (15, 30), I need to determine whether the ranges overlap each other. The algo needs to catch: (10, 20) (15, 25) (15, 25) (10, 20) (10, 25) (15, 20) and (15, 20) (10, 25) I can think of lots of ways to do this but it's in a tight loop so I need it to be as efficient as possible. Any help welcome :-) Cheers -Rob -- http://mail.python.org/mailman/listinfo/python-list
[ANN] Pydev and Pydev Extensions 1.0.2 release
Hi All, Pydev and Pydev Extensions 1.0.2 have been released Check http://www.fabioz.com/pydev for details on Pydev Extensions and http://pydev.sf.net has for details on Pydev Highlights in Pydev Extensions: --- - New feature in the debugger: the console is available for probing when in 'suspendend mode' - New feature in code analysis: Provided a way to consider tokens that should be in the globals - Halt fix when too many matches where found in the go to definition. - Code analysis minor bugs fixed. - Error when opening browser fixed. Highlights in Pydev: --- - Jython debugging now working. - Code coverage does not report docstrings as not being executed. - Freeze when making a 'step-in' fixed in the debugger. - Grammar generated with javacc version 4.0 Cheers, Fabio -- Fabio Zadrozny -- Software Developer ESSS - Engineering Simulation and Scientific Software www.esss.com.br Pydev Extensions http://www.fabioz.com/pydev PyDev - Python Development Enviroment for Eclipse http://pydev.sf.net http://pydev.blogspot.com -- http://mail.python.org/mailman/listinfo/python-list
Re: MySQL
Hi Wolfram, Thanks for the tip, after some server issues I am pleased to say the library appears to work perfectly with MySQL 5. Best, rod -- http://mail.python.org/mailman/listinfo/python-list
Re: Is empty string cached?
Farshid Lashkari wrote: > However, the following commands add to my confusion: > > >> a = 'wtf?' > >> b = 'wtf?' > >> a is b > False > > So how are string literals cached? Is there an explanation somewhere? Is > it some freaky voodoo, and I should just assume that a string literal > will always generate a new object? A few comments (which I hope are correct, but which I hope you will read then mostly ignore since you probably shouldn't be designing based on this stuff anyway): 1. What you see at the interactive prompt is not necessarily what will happen in a compiled source file. Try the above test with and without the question mark both at the interactive prompt and in source and see. 2. The reason for the difference with ? is probably due to an optimization relating to looking up attribute names and such in dictionaries. wtf? is not a valid attribute, so it probably isn't optimized the same way. 2.5. I think I had a third comment like the above but after too little sleep last night it seems it's evaporated since I began writing... 3. As Steve or someone said, these things are implementation details unless spelled out explicitly in the language reference, so don't rely on them. 4. If you haven't already written your code and profiled and found it lacking in performance and proving that the cause is related to whether or not you hoisted the string literal out of the loop, you're wasting your time and this is a good opportunity to begin reprogramming your brain not to optimize prematurely. IMHO. FWIW. :-) -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: ANN: FreeImagePy 1.2.2
Claudio Grondi wrote: > Knowing some details about PIL and as good as no details about > FreeImage, I would like in this context to become enlightened by the > answer to the question, when does it make sense to use FreeImage > instead of PIL? Into some little environments, like tiff with G3/G4 compressions and multi-page files. > From what I know up to now I can't see any use for FreeImage :-( . > Like I say to freeimagepy site, I start to wrote it *only* because I needed a simple python library for manipulate fax images (G3/G4) that PIL can't. I need it into my python fax client [hylapex] that it's connect to hylafax server. Of course, It wouldn't be a PIl replacement ;)! > Claudio Michele -- http://mail.python.org/mailman/listinfo/python-list
Re: looping over more than one list
Iain King si è profuso/a a scrivere su comp.lang.python tutte queste elucubrazioni: [cut] I think you should take a look at the zip() function. You can use for with it like this: for elem1, elem2, elem3 in zip(list1, list2, list3): -- Alan Franzoni <[EMAIL PROTECTED]> - Togli .xyz dalla mia email per contattarmi. Rremove .xyz from my address in order to contact me. - GPG Key Fingerprint: 5C77 9DC3 BD5B 3A28 E7BC 921A 0255 42AA FE06 8F3E -- http://mail.python.org/mailman/listinfo/python-list
Re: Encryption
dirvine wrote: > HI hope you can help (know you can). > > I am looking for a very strong AIS or better symetrical encryption in > python. Any suggestions ideas welcome. I have spent a lot of time > looking everywhere at pycrypto and many others but is a wee bit of a > minefield out there. Anyone have any experience of a true encryption > (not xor or anything weak). I am looking for something strong enough to > encrypt your credit card info and publish file on website (no not > actually do that but have encryption strong enough if you did). > > Many thanks and if I have missed obvious docs please take it easy on me > - I am new here :-) > Take a look here. This package works perfectly for us. http://www.amk.ca/python/code/crypto -Larry -- http://mail.python.org/mailman/listinfo/python-list
Re: ANN: FreeImagePy 1.2.2
eg.: .dds (compressed texture file format) widely used in 3d games but not accessible in pil -- http://mail.python.org/mailman/listinfo/python-list
Installing packages in /usr/local
Hallöchen! I use the Suse 10.0 RPM of Python 2.4. Unfortunately, it doesn't seem to look for packages in /usr/local because "prefix" and "exec_prefix" in site.py are the same (namely usr/). I have my own packages in /usr/local/lib/python/site-packages. (Due to easier backup, I don't want to change that.) What is the best way to make Python look there? I tried PYTHONPATH but I had trouble with a Python cron job which didn't have the proper environment. I could edit site.py manually, however, I wonder whether there is a cleaner way? Tschö, Torsten. -- Torsten Bronger, aquisgrana, europa vetusICQ 264-296-646 -- http://mail.python.org/mailman/listinfo/python-list
Re: Visual Report Editor
Pawel wrote: > I plan to make Visual Reporting Editior, a new product for > corporate-class systems. Data will be in XML and in my application, > designer should be able to make fascinating templates of reports. I > will use Python and MSVS 2005 Pro. My question is, which libaries will > be useful in my job. I plan to buy Qt and make visual layer of > application using Qt. I'm making businessplan soI have to decide which > tool will be useful. Is Qt best choice, maybe I should buy something > different? Before you go to all that work, please take a look at the Dabo Report Designer, which uses wxPython for the UI and ReportLab for the PDF generation. There's a 23-minute screencast here which may give you an idea if its design is compatible with yours: http://dabodev.com/documentation It isn't complete and I could certainly use help making it so. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Win32_Process.Create -- not starting process
Tim,
I am skipping using the batch file and only executing the python
script directly...and so far it works fine.
So now I have:
pid, retVal =
wmi.WMI("1.2.3.4").new("Win32_Process").Create(CommandLine="c:\python\python.exe
c:\some_script.py")
Thanks again...not sure why when using the batch file to start it
wouldnt always work, but as long is it works now!
--
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Some general questions about using "stdin","stdout"....
Hi!I'm new in Python and i'd like to ask some general questions about
stdin,stdout...
Firstly...
if we type like something like :
cat "file.txt"|python somefile.py
#somefile.py
import sys
text=sys.stdin.read()
...then "sys.stdin.read()" will read from "cat"s stdout...
However,if i type inside a program,something like
#someprog.py
import sys
print "hello"|sys.stdin.read()
.the screen hangs..why is that?isn't the same situation as "cat"?
in addition to this...
Why can't i "write" to the stdin?
Isn't it being used as a file object like all the others?
for example
sys.stdin.close() or
open('sys.stdin','w+') or
sys.stdin.write("something") etc... don't work...
At last,let's consider "sys.stdin.read(3)"
If i type that,the program "waits" for me to type some characters,and then
prints the first three...
However,doesn't this action actually include a "writing" to stdin and then
a "reading" from that?
I'm really confused...
Any help would be highly appreciated...
Thanks a lot.
_
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looping over more than one list
When I loop over one list I use: for item in items: print item but often I want to loop through two lists at once, and I've been doing this like I would in any other language - creating an index counter and incrementing it. For example, (completely arbitrary), I have two strings of the same length, and I want to return a string which, at each character position, has the letter closest to 'A' from each of the original strings: def lowest(s1,s2): s = "" for i in xrange(len(s1)): s += lowerChar(s1[i],s2[i]) return s this seems unpythonic, compared to something like: def lowest(s1,s2): s = "" for c1,c2 in s1,s2: s += lowerChar(c1,c2) return s this doesn't work - s1,s2 becomes a tuple. Is there a way to do this that I'm missing? I don't see it in the docs. This works: def lowest(s1,s2): s = "" for c1,c2 in [x for x in zip(s1,s2)]: s += lowerChar(c1,c2) return s but it's hardly any more elegant than using a loop counter, and I'm guessing it's performance is a lot worse - I assume that the zip operation is extra work? Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: ANN: FreeImagePy 1.2.2
> Knowing some details about PIL and as good as no details about > FreeImage, I would like in this context to become enlightened by the > answer to the question, when does it make sense to use FreeImage instead > of PIL? > From what I know up to now I can't see any use for FreeImage :-( . both freeimagepy and freeimage are released under the GPL, PIL is not. -- Andrew Gwozdziewycz <[EMAIL PROTECTED]> http://ihadagreatview.org http://plasticandroid.org -- http://mail.python.org/mailman/listinfo/python-list
Re: web crawler in python or C?
On 15 Feb 2006 21:56:52 -0800, abhinav <[EMAIL PROTECTED]> wrote: > Hi guys.I have to implement a topical crawler as a part of my > project.What language should i implement > C or Python? Why does this keep coming up on here as of late? If you search the archives, you can find numerous posts about spiders. One interesting fact is that google itself starting with their spiders in python. http://www-db.stanford.edu/~backrub/google.html I'm _sure_ it'll work for you. -- Andrew Gwozdziewycz <[EMAIL PROTECTED]> http://ihadagreatview.org http://plasticandroid.org -- http://mail.python.org/mailman/listinfo/python-list
[ANN] pyqonsole-0.2.0
Logilab has released pyqonsole-0.2.0 Pyqonsole is a X Window terminal written in Python. The code is based on konsole, and it uses the Qt toolkit. It is mainly meant for use by Python application developpers who would like to embed a terminal in their application, but it can be used as a not blazingly fast XTerm replacement. Download: http://www.logilab.org/projects/pyqonsole Mailing List: http://www.logilab.org/mailinglists/python_projects -- Alexandre Fayolle LOGILAB, Paris (France). http://www.logilab.com http://www.logilab.fr http://www.logilab.org Retrait du projet de loi DADVSI: http://eucd.info/petitions/index.php?petition=2 signature.asc Description: Digital signature -- http://mail.python.org/mailman/listinfo/python-list
Re: ANN: FreeImagePy 1.2.2
Michele Petrazzo wrote:
> FreeImagePy 1.2.2 is available at freeimagepy.sf.net
>
> What is?
> It' a python wrapper for FreeImage, Open Source library for developers
>who would like to support popular graphics image formats.
>
> How work?
> It use a binary freeimage library present on the system and ctypes.
>
> Major changes from 1.2.0:
> New convertToPil function:
> i = FreeImagePy.Image("myImage.ext")
> pil = i.convetToPil()
> Some bugs solved
>
> Michele Petrazzo
Knowing some details about PIL and as good as no details about
FreeImage, I would like in this context to become enlightened by the
answer to the question, when does it make sense to use FreeImage instead
of PIL?
From what I know up to now I can't see any use for FreeImage :-( .
Claudio
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mod_python help!
I'm getting and internal server error when | run the following
mod_python script. I am actually trying to run Django.
Script:
from mod_python import apache
def handler(req):
req.content_type = 'text/plain'
req.write("Under Construction")
return apache.OK
Here is some other relevant info. Hope this is not too much:
Debian 3.x/python2.3.5/mod_python3.1.3/Apache2.0.54
from the command line test:
>>> import mod_python.psp
Traceback ( most recent call last ):
File "", line 1,in ?
File "/usr/lib/python2.3/site-packages/mod_python/psp.py",line20, in
?
import apache,Session,util,-psp
File "/usr/lib/python2.3/site-packages/mod_python/apache.py,line28,in ?
import _apache
ImportError: No Module named _apache
...
Virtual Server Configuration
NameVirtualHost *
ServerName www.wyah-webs.com
ServerAlias wyah-webs.com *.wyah-webs.com
DocumentRoot /var/www/wyah-webs
ServerAdmin [EMAIL PROTECTED]
Options FollowSymLinks
AllowOverride None
DirectoryIndex index.html mptest.py
AddHandler mod_python .py
PythonHandler mptest
PythonDebug On
SetHandler mod_python
PythonHandler django.core.handlers.modpython
SetEnv DJANGO_SETTINGS_MODULE ard_proj.settings
PythonDebug On
SetHandler none
ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
AllowOverride None
Options ExecCGI -MultiViews +SymLinksIfOwnerMatch
Order allow,deny
Allow from all
ErrorLog /var/log/apache2/www.wyah-webs.com_error.log
# Possible values include: debug, info, notice, warn, error, crit,
# alert, emerg.
LogLevel warn
CustomLog /var/log/apache2/www.wyah-webs.com_access.log combined
ServerSignature On
#Alias /doc/ "/usr/share/doc/"
#
#Options Indexes MultiViews FollowSymLinks
#AllowOverride None
#Order deny,allow
#Deny from all
#Allow from 127.0.0.0/255.0.0.0 ::1/128
#
...
main server configuration
# Based upon the NCSA server configuration files originally by Rob
McCool.
# Changed extensively for the Debian package by Daniel Stone
<[EMAIL PROTECTED]>
# and also by Thom May <[EMAIL PROTECTED]>.
# ServerRoot: The top of the directory tree under which the server's
# configuration, error, and log files are kept.
#
# NOTE! If you intend to place this on an NFS (or otherwise network)
# mounted filesystem then please read the LockFile documentation
# (available at
http://www.apache.org/docs/mod/core.html#lockfile>);
# you will save yourself a lot of trouble.
ServerRoot "/etc/apache2"
# The LockFile directive sets the path to the lockfile used when Apache
# is compiled with either USE_FCNTL_SERIALIZED_ACCEPT or
# USE_FLOCK_SERIALIZED_ACCEPT. This directive should normally be left
at
# its default value. The main reason for changing it is if the logs
# directory is NFS mounted, since the lockfile MUST BE STORED ON A
LOCAL
# DISK. The PID of the main server process is automatically appended to
# the filename.
LockFile /var/lock/apache2/accept.lock
# PidFile: The file in which the server should record its process
# identification number when it starts.
PidFile /var/run/apache2.pid
# Timeout: The number of seconds before receives and sends time out.
Timeout 300
# KeepAlive: Whether or not to allow persistent connections (more than
# one request per connection). Set to "Off" to deactivate.
KeepAlive On
# MaxKeepAliveRequests: The maximum number of requests to allow
# during a persistent connection. Set to 0 to allow an unlimited
amount.
# We recommend you leave this number high, for maximum performance.
MaxKeepAliveRequests 100
# KeepAliveTimeout: Number of seconds to wait for the next request from
the
# same client on the same connection.
KeepAliveTimeout 15
##
## Server-Pool Size Regulation (MPM specific)
##
# prefork MPM
# StartServers . number of server processes to start
# MinSpareServers .. minimum number of server processes which are
kept spare
# MaxSpareServers .. maximum number of server processes which are
kept spare
# MaxClients ... maximum number of server processes allowed to
start
# MaxRequestsPerChild .. maximum number of requests a server process
serves
StartServers 5
MinSpareServers 5
MaxSpareServers 10
MaxClients 20
MaxRequestsPerChild 0
# pthread MPM
# StartServers . initial number of server processes to start
# MaxClients ... maximum number of server processes allowed to
start
# MinSpareThreads .. minimum number of worker threads which
Re: Visual Report Editor
Pawel wrote: > Hello, Hi Pawel, > I plan to make Visual Reporting Editior, a new product for > corporate-class systems. Data will be in XML and in my application, > designer should be able to make fascinating templates of reports. I > will use Python and MSVS 2005 Pro. What are MSVS 2005 Pro ? > My question is, which libaries will be useful in my job. I plan to > buy Qt and make visual layer of application using Qt. I'm making > businessplan soI have to decide which tool will be useful. Is Qt best > choice, maybe I should buy something different? Qt has a "strange" license for a graphical toolkit, it is release under GPL/commercial license, so if you want to include your new Reporting Editior into a commercial product, you have to pay a license for it. Different thing is if you use wx or gtk, that has other, more "permissive" licenses. I (my company), for our project, has create a "Reporting Editior" based on wx, following the pySketch tool, but now has about all the code rewrite. It has some little problems with the auto-resizeable objects (text only for now), that, into the engine that should compose the page, not are displayed correctly. On the other hand has a lot of worker functions, like: - model-view framework - object-like develop, so it's simple to add new drawing objects - xml read and save - multi-page size (A4, A3, etc...) - multi-block (head, title, text [more that one], food, end) - align-resize object - infinite undo-redo - image support - multi-layer (9 layers) - text block wrap, align right/left/center vertically/horrizontally - more other... Now I haven't the mind and the time for solve the problems, but if you want to complete it, or help me to do it, I'll send you the code, so after we'll a new -open source (do you like wxWidgets license? [LGPL] )- *Visual Reporting Editior* > > Pawel > Michele -- http://mail.python.org/mailman/listinfo/python-list
Re: any ftpd written in python?
On Thu, 16 Feb 2006 14:07:55 +0800, Kenneth Xie <[EMAIL PROTECTED]> wrote: >I need a simple ftpd example in pure python. Is there already such a >ftpd available? >Thank you very much in advance. Twisted includes an FTP server: [EMAIL PROTECTED]:~$ mkdir a a/b a/c a/d [EMAIL PROTECTED]:~$ mktap ftp --root a [EMAIL PROTECTED]:~$ twistd -f ftp.tap [EMAIL PROTECTED]:~$ ftp localhost 2121 Connected to kunai. 220 Twisted SVN-Trunk FTP Server Name (localhost:exarkun): anonymous 331 Guest login ok, type your email address as password. Password: 230 Anonymous login ok, access restrictions apply. Remote system type is UNIX. Using binary mode to transfer files. ftp> ls 200 PORT OK 125 Data connection already open, starting transfer drwxr-xr-x 2 exarkun exarkun 4096 Feb 16 14:15 b drwxr-xr-x 2 exarkun exarkun 4096 Feb 16 14:15 c drwxr-xr-x 2 exarkun exarkun 4096 Feb 16 14:15 d 226 Transfer Complete. ftp> quit 221 Goodbye. Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Embedding an Application in a Web browser
Atanas Banov wrote: > paron wrote: > > I forgot -- I like the idea of Kerrigell, too. It runs on top of > > CherryPy, and lets you use python either in the server (which is just a > > little program on your local machine) or embedded in the html pages, or > > in a Kerrigell service, which is an application server based on Python. > > oh sure, why make it simple, when we can make it difficult?! I don't see how running a local Web application server is more difficult than messing around with ActiveX and/or Active Scripting (or whatever it's called). Remember that Python already has various HTTP server classes in the standard library, and making use of these classes is very easy. I'd rather do that than touch ActiveX with a very long stick, and the Active Scripting stuff, whilst amusing, is a known security concern. > your solution is like using a sledgehammer to crack a nut! > > "... I keep hearing the sound of nuts being pulverized..." > http://www.bobcongdon.net/blog/2005/11/java-sledgehammer.html Why am I not surprised that the first three words of the quoted blog article are "David Heinemeier Hansson"? Few people contributing to comp.lang.python would suggest J2EE as a solution here, so I don't quite see what relevance this particular hype echo from the blogosphere has in this case, especially since running BaseHTTPServer isn't exactly like running JBoss. Sure, to have animated graphics is likely to stretch any Web-based interface, despite recent support for things like SVG and "destandardised" innovations like canvases in Web browsers. But if cross-platform portability ever becomes an issue, the vanilla Web application option is quite possibly the best route; whilst one can embed Python in Konqueror with the right packages today, and whilst support for Python scripting in Mozilla is coming along, it'll be a long time before any piece of Python code will be able to run on more than one of these configurations without modification. And beyond Active Scripting, who can really be sure what Internet Explorer will eventually support? Paul -- http://mail.python.org/mailman/listinfo/python-list
OT- wxPython mailing list problems
Sorry about asking here, but has anyone experienced, that no message can be sent to the mailing list? Neither with Gmane, nor with Google mail. I always get this reply: from [EMAIL PROTECTED] """ Hi. This is the qmail-send program at sunsite.dk. I'm afraid I wasn't able to deliver your message to the following addresses. This is a permanent error; I've given up. Sorry it didn't work out. <[EMAIL PROTECTED]>: ezmlm-reject: fatal: List address must be in To: or Cc: (#5.7.0) """ -- Franz Steinhaeusler -- http://mail.python.org/mailman/listinfo/python-list
Re: Visual Report Editor
Pawel wrote: > Hello, > I plan to make Visual Reporting Editior, a new product for > corporate-class systems. Data will be in XML and in my application, > designer should be able to make fascinating templates of reports. I > will use Python and MSVS 2005 Pro. My question is, which libaries will > be useful in my job. I plan to buy Qt and make visual layer of > application using Qt. I'm making businessplan soI have to decide which > tool will be useful. Is Qt best choice, maybe I should buy something > different? If you do have the money, Qt is what you want to get. I've been cross-OS-developing with it for Win, Linux and MacOs and it never let me down. Even if you don't need cross-platform, the toolchain alone together with the really good design are worth it. Currently the move to Qt4 in the PyQt community is done, you might consider waiting until that is reasonably stable or go for the early snapshots and then buy stuff when its released. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: web crawler in python or C?
abhinav wrote: > Hi guys.I have to implement a topical crawler as a part of my > project.What language should i implement Oh, and there's some really good books out there, besides the Orilly Spidering Hacks. Springer Verlag has a couple books on "Text Mining" and at least a couple books with "web intelligence" in the title. Expensive but worth it. -- http://mail.python.org/mailman/listinfo/python-list
Re: Databases and python
Dan Stromberg wrote:
> I've been putting a little bit of time into a file indexing engine
[...]
> So far, I've been taking the approach of using a single-table database
> like gdbm or dbhash [...] and making each entry keyed by
> a word, and under the word in the database is a null terminated list of
> filenames (in http://dcs.nac.uci.edu/~strombrg/base255.html representation).
>
[...]
> the program just isn't performing like I'd like it to.
>
> And I think it's because despite the caching and minimal representation
> conversion, it's still just too slow converting linear lists to arrays
> back and forth and back and forth.
I think I follow. The straightforward method of building the
list of files associated with a word is order n**2 time. On each
new entry, you look up the entire string, append one file-id to
it, and write the new version back.
> So this leads me to wonder - is there a python database interface that
> would allow me to define a -lot- of tables? Like, each word becomes a
> table, and then the fields in that table are just the filenames that
> contained that word. That way adding filenames to a word shouldn't bog
> down much at all.
Well, you could use simple files instead of fancy database tables.
Below is a demo of an alternate technique that uses bsddb B-Trees,
and puts both the word and the file-id in the key. I don't know
how efficient it is for real data, but at least the time won't grow
as Theta(n**2).
--Bryan
import bsddb
import urllib
def add_words_from_file(index, fname, word_iterator):
""" Pass the open-for-write bsddb B-Tree, a filename, and a list
(or any interable) of the words in the file.
"""
fname = urllib.quote_plus(fname)
s = set()
for word in word_iterator:
if word not in s:
s.update(word)
key = '%s %s' % (urllib.quote_plus(word), fname)
index[key] = ''
index.sync()
def lookup(index, word):
""" Pass the B-Tree (as built with add_words_from_file) and a
word to look up. Returns list of files containing the word.
"""
word = urllib.quote_plus(word)
fname_list = []
try:
current = index.set_location(word)
while True:
(key, _) = current
(w, fname) = key.split()
if w != word:
break
fname_list.append(urllib.unquote_plus(fname))
current = index.next()
except KeyError:
pass
return fname_list
def test():
index = bsddb.btopen('junktest.bdb', 'n')
data =[
('bryfile.txt', 'nor heed the rumble of a distant drum'),
('junkfile.txt', 'this is the beast, the beast so sly'),
('word file.txt', 'is this the way it always is here in Baltimore')
]
for (fname, text) in data:
words = text.split()
add_words_from_file(index, fname, words)
for word in ['is', 'the', 'heed', 'this', 'way']:
print '"%s" is in files: %s' % (word, lookup(index, word))
test()
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Re: web crawler in python or C?
Paul Rubin wrote: > "abhinav" <[EMAIL PROTECTED]> writes: > > maintaining huge data structures.What should be the language so as > > not to compromise that much on speed.What is the performance of > > python based crawlers vs C based crawlers.Should I use both the > > languages(partly C and python).How should i decide what part to be > > implemented in C and what should be done in python? Please guide > > me.Thanks. > > I think if you don't know how to answer these questions for yourself, > you're not ready to take on projects of that complexity. My advice > is start in Python since development will be much easier. If and when > you start hitting performance problems, you'll have to examine many > combinations of tactics for dealing with them, and switching languages > is just one such tactic. There's another potential bottleneck, parsing HTML and extracting the text you want, especially when you hit pages that don't meet HTML 4 or XHTML spec. http://sig.levillage.org/?p=599 Paul's advice is very sound, given what little info you've provided. http://trific.ath.cx/resources/python/optimization/ (and look at psyco, pyrex, boost, Swig, Ctypes for bridging C and python, you have a lot of options. Also look at Harvestman, mechanize, other existing libs. -- http://mail.python.org/mailman/listinfo/python-list
Visual Report Editor
Hello, I plan to make Visual Reporting Editior, a new product for corporate-class systems. Data will be in XML and in my application, designer should be able to make fascinating templates of reports. I will use Python and MSVS 2005 Pro. My question is, which libaries will be useful in my job. I plan to buy Qt and make visual layer of application using Qt. I'm making businessplan soI have to decide which tool will be useful. Is Qt best choice, maybe I should buy something different? Pawel -- http://mail.python.org/mailman/listinfo/python-list
Re: MySQL
rodmc wrote: > I need to write a Python application which connects to a MySQL 5.0 > database. Can anyone point me in the right direction or a compatible > library? > > Best, > > rod > See http://sourceforge.net/projects/mysql-python HTH, Wolfram -- http://mail.python.org/mailman/listinfo/python-list
MySQL
I need to write a Python application which connects to a MySQL 5.0 database. Can anyone point me in the right direction or a compatible library? Best, rod -- http://mail.python.org/mailman/listinfo/python-list
Re: Embedding an Application in a Web browser
>From the OP: As for the application it has to be able display simple animated graphics such as circles, lines and squares. However if someone clicks on a shape it should open up another application, such as Word. Thanks, Rod Python Newbie The application itself can sit on the local users computer, rather than actually being downloaded via the web. It will be retrieving data from a variety of sources. I was thinking that the security provisions might make it difficult for the script in the browser to interact with the OS. If that is "simple" to get around, then I agree, Karrigell is overkill. OTOH, Karrigell makes it simple to interact with the local machine's OS, and especially if you are a beginner at Python. YMMV, of course. Thanks for offering your opinion. Ron -- http://mail.python.org/mailman/listinfo/python-list
Re: Excel and TrackChanges
If i move the Save after the HighlightChangesOptions it will popup a message saying it can only be used when workbook is saved. The problem is actually not only in python, i figured out that the samples in msdn (which do the same) don't work in VBA also (if i give my macros a shortcut). I have now fixed-it with ApplyAllChanges(), which gives me thing i need (i need the track changes just to create a log file of whats happening). thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: apache mod_python problem
please ignore that last message, the instructions on that webpage worked, it was my fault. Thanks, Ido. -- http://mail.python.org/mailman/listinfo/python-list
Extend/embedd python problem?
Hello all, I am considering python as a 'scripting' language to be used in my application where users must be able to write their own code to access application data, use the application mechanisms to gather various data and basicly must be able to control the application itself. Currently, to accomplish this task, my app uses my custom C-like language and my bytecode interpreter. In this case I am able to control the execution of a single 'instruction' in my interpreter and interpret the user code when I want. It also enables me to support multiple 'user tasks' (not a system LWP-like tasks, but a higher-level concurrent execution simulation - each task has it's own interpreter and each interpreter is executed every n-th iteration for example). I have glanced at the python/C api ref manual and know I can use the 'PyRun_InteractiveOne' to execute a single python statement, but am not sure if there's a way to 'precompile' python code and prepare it for execution so I can interpret the precompiled statements one-by-one, similarly to my custom interpreter. I noticed the 'Py_CompileString' but am not sure what to do and how to interact with 'PyObject*' it returns me - how do I run it, can I interrupt it when it's executing, can I run it on per-statement basis'? Any help or pointers where to look for answers to my questions is grately apreciated. Thanks, Regards, Mario -- http://mail.python.org/mailman/listinfo/python-list
Re: any ftpd written in python?
Kenneth Xie <[EMAIL PROTECTED]> wrote: > I need a simple ftpd example in pure python. Is there already such a > ftpd available? > Thank you very much in advance. self-advertising: http://melkor.dnp.fmph.uniba.sk/~garabik/pyftpd.html it is a bit dated and I do not develop it anymore, but as a base of your own server software it can be quite good. -- --- | Radovan Garabík http://kassiopeia.juls.savba.sk/~garabik/ | | __..--^^^--..__garabik @ kassiopeia.juls.savba.sk | --- Antivirus alert: file .signature infected by signature virus. Hi! I'm a signature virus! Copy me into your signature file to help me spread! -- http://mail.python.org/mailman/listinfo/python-list
Re: apache mod_python problem
Hi Graham, thank you for that link but it didn't help. I've followed the instructions, yet In the 'basic-content-handler' section, after getting to the point where it says to add this to the main Apache configuration file: AllowOverride FileInfo I replaced /some/directory with the correct directory and restarted apache2 and stilll get the same response - firwfox asks to save the response to a file. Does it matter where in the apache2 configuration file I've located these 3 lines? I've just added them at the end, just before the last line: Thank you in advance, Ido. -- http://mail.python.org/mailman/listinfo/python-list
Re: web crawler in python or C?
"abhinav" <[EMAIL PROTECTED]> writes: > It is DSL broadband 128kbps.But thats not the point. But it is the point. > What i am saying is that would python be fine for implementing fast > crawler algorithms or should i use C.Handling huge > data,multithreading,file handling,heuristics for ranking,and > maintaining huge data structures.What should be the language so as > not to compromise that much on speed.What is the performance of > python based crawlers vs C based crawlers.Should I use both the > languages(partly C and python).How should i decide what part to be > implemented in C and what should be done in python? Please guide > me.Thanks. I think if you don't know how to answer these questions for yourself, you're not ready to take on projects of that complexity. My advice is start in Python since development will be much easier. If and when you start hitting performance problems, you'll have to examine many combinations of tactics for dealing with them, and switching languages is just one such tactic. -- http://mail.python.org/mailman/listinfo/python-list
Re: multiple inheritance
thanks, you pointed exactly on what distrurbed me. I'll see what I can do with cooperative methods. -- http://mail.python.org/mailman/listinfo/python-list
pymssql and date format
hi i am using pymmsql to query a date column in MSSQL database table. However the result shows for example (datetime.datetime(2006, 2, 16, 17, 50, 19) which is supposed to be 2006-02-16 17:50:19.000 anyway to correct query a date column using pymssql so that it gives the correct date format? thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: multi/double dispatch, multifunctions once again
AndyL wrote:
> Hi,
(OT : please repeat the question in the body of the post...)
> Where I can find a module supporting that?
http://peak.telecommunity.com/DevCenter/PyConGenericFunctions
--
bruno desthuilliers
python -c "print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in '[EMAIL PROTECTED]'.split('@')])"
--
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