🌐 Mailman 3 August 2006 - Python-list - python.org

list comprehension syntax..?
by Gregory Guthrie Aug. 1, 2006

Aug. 1, 2006

Sorry for a simple question- but I don't understand how to parse this use of a list comprehension. The "or" clauses are odd to me. It also seems like it is being overly clever (?) in using a lc expression as a for loop to drive the recursion. Thanks for any insight! Gregory ------------------------- # http://markbyers.com/moinmoin/moin.cgi/ShortestSudokuSolver def solve(board): i=board.find('0') # find next open cell if i<0: # done if none... print board; exit("Done") [ m in [(i-j)%9*(i/9^j/9)*(i/27^j/27|i%9/3^j%9/3) or board[j] for j in range(81) ] or solve(board[:i]+m+board[i+1:]) for m in'%d'%5**18 ] ----== 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: Semantics of propagated exceptions
by Thomas Lotze Aug. 1, 2006

Aug. 1, 2006

Sorry for not answering such a long time. It's because my question originated from a discussion within our company which moved out of focus shortly after I posted, and over waiting for some response from them before replying here, I forgot about it. Steve Holden wrote: >> - f might catch E exceptions from the implementation and raise some >> other error in their stead, maybe with an appropriate message or >> treating the traceback in some helpful way. This destroys the original >> exception. >> > My "solution", of course, takes this approach. Good to see that my "gut feeling" as to the most pythonic approach seems to coincide with the answers I've received ;o) -- Thomas

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Re: Windows vs. Linux
by Gerhard Fiedler Aug. 1, 2006

Aug. 1, 2006

On 2006-08-01 12:31:01, Sybren Stuvel wrote: > Ehm... replace that with "the latter with bonk on every OS except > Microsoft Windows". Windows is the weird one in OS-land, because they > are the only one that use the most widely used escape-character (the > backslash) as path separator. Is that really true? From what I know, it's more like this: - Unix-type systems: '/' - Windows-type systems: '\' - Mac OS: ':' - OpenVMS: '.' - ... Maybe someone else can fill in some of the missing OSes. It doesn't seem to look like Windows is the odd man out; it rather seems that every type of OS uses its own separator. (URLs probably use the slash because the internet protocols have been developed largely on Unix-type systems for use with Unix-type systems?) Gerhard

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Re: Nested function scope problem
by Antoon Pardon Aug. 1, 2006

Aug. 1, 2006

On 2006-08-01, Dennis Lee Bieber <wlfraed(a)ix.netcom.com> wrote: > On Tue, 1 Aug 2006 11:12:31 -0300, Gerhard Fiedler <gelists(a)gmail.com> > declaimed the following in comp.lang.python: > >> There's maybe a point in comparing Python variables to C pointers. But it >> lacks in the respect that a C programmer is used to modify memory locations >> through pointers. A Python programmer isn't used to modify memory locations >> in the first place, and simple objects don't get modified at all. There's >> no Python equivalent to "int*p=345; *p++;". (There's no need for that in >> Python; I'm not saying this shows a superiority of C. It just shows a >> different concept of what "variable" means.) >> > Python > > c = c + 100 > > pseudo-C (where I use _p to indicate explicit pointer; and all data > objects are a structure of the form: int ref_count; <object type> data) > > scratch_p = malloc() > scratch_p->data = c_p->data + 100 > scratch_p->ref_count = 1 > c_p->ref_count-- > if !c_p->ref_count > free(c_p) > c_p = scratch_p > > ------- > b = a > is > b = a > b->ref_count++ > > > >> For me, the point of this discussion was that it makes sense to look at it >> /differently/. Once you've done that, there's no problem in continuing to >> use the (vaguely defined) term "variable". >> > > Think the above is "different" enough <G> The above are implementation details. Suppose I write a C-interpreter and then would translate a statement like "c = c + 100" into actions the interpreter would have to take in order to excute that statement. Something like: c-addr_p = GetAddress("c"); c-value = *c-addr_p; sum = c-value + 100; *c-addr_p = sum; That look different enough from just "c = c + 100". So maybe C has no variables either. -- Antoon Pardon

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code to retrieve web mail?
by John Savage Aug. 1, 2006

Aug. 1, 2006

I have a free web mail address and would like to use python to retrieve files that have been emailed to me. The basic code would accommodate cookies, a login name and password, then download using the full URL I can provide. From postings here I thought mechanize held promise, but I've found it to contain filenames that are invalid for MSDOS (too many characters, and/or too many dots in the name, etc.) so I have little hope that the mechanize module can be used. I'm running python2.4.2 on plain MSDOS (not windows), so would appreciate a pointer to sample code that can do the job. I know that curl has this capability, but I'll learn something by tinkering with python code. Thanks. -- John Savage (my news address is not valid for email)

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after an image is moved to a new location, how to delete the image at the old location?
by zxo102 Aug. 1, 2006

Aug. 1, 2006

Hi everyone, As shown in the code below (modified based on the Image.py in wxpython demo), an image is created at location 1: (50,10) with rotated angle 1.12. Now, suppose I got another set of new data, I want to move the image to location 2: (166,400) with rotated angle 1.5. case 1: if I use "wx.StaticBitmap(panel, -1, bmp2, (166, 400), (bmp2.GetWidth(), bmp2.GetHeight()))", everything is fine but I don't know how to delete the image at location 1. case 2: If I use "kk.SetBitmap(bmp2)" (see the code below), the rotated image (angle 1.5) is put to location 1: (50,10) instead of location 2: (166,400). Or I don't know how to move the image to the new location (166,400). anybody knows how to solve the above problem? Thanks a lot. Ouyang ############################################# def runTest(frame, nb, log): bmp = wx.Image(opj('bitmaps/image.bmp'), wx.BITMAP_TYPE_BMP) bmp.SetMask(True) # image.bmp is originally located in (50,10) with rotated angle 1.12 x = 50 y = 10 angle = 1.12 bmp1 = bmp.Rotate(angle, (x,y), True,None) bmp1 = bmp1.ConvertToBitmap() panel = wx.Panel(nb, -1) kk = wx.StaticBitmap(panel, -1, bmp1, (x, y), (bmp1.GetWidth(), bmp1.GetHeight())) # Now image.bmp is relocated at (166,400) with rotated angle 1.5 x= 166 y = 400 angle = 1.5 bmp2 = bmp.Rotate(angle, (x,y), True,None) bmp2 = bmp2.ConvertToBitmap() wx.StaticBitmap(panel, -1, bmp2, (x,y), (bmp2.GetWidth(), bmp2.GetHeight())) #kk.SetBitmap(bmp2) return panel ###########################################################3

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fast pythonic algorithm question
by Guyon Morée Aug. 1, 2006

Aug. 1, 2006

hi all, i have a big list of tuples like this: [ (host, port, protocol, startime, endtime), .. ] etc now i have another big(ger) list of tuples like this: [(src_host, src_port, dest_src, dest_port, protocol, time), ... ] etc now i need to find all the items in the second list where either src_host/src_port or dest_host/dest_port matches, protocol matches and time is between starttime and end time. After trynig some stuff out i actually found dictionary lookup pretty fast. Putting the first list in a dict like this: dict[(host,port,protocol)] = (starttime, endtime) then: if (((src_host,src_port, protocol) in dict or (dest_host, dest_port, protocol) in dict) and starttime < time < endtime): print "we have a winner" I have also been looking at the bisect module, but couldnt figure out if it was what I was looking for... any ideas? regards, Guyon Moree http;//gumuz.looze.net/

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Re: Can't get LCHARVAR's with InformixDB
by fhurley＠gmail.com Aug. 1, 2006

Aug. 1, 2006

Carsten Haese wrote: > Could you possibly send me a minimal test script that shows the problem? > Also, in case it matters, I'd like to know which versions of IDS and > CSDK or Informix Connect you're using. Here's a sample script: sql = '''select msg_tx from dev_log''' import informixdb conn = informixdb.connect('mydb') cursor = conn.cursor() cursor.execute(sql) print 'description is <%s>' % cursor.description print cursor.fetchall() Output is: description is <('msg_tx', 'lvarchar', 0, 0, None, None, 1)> [('',), ('',), ('',), ('',), ('',), ('',)] But one of them should be: '''Something:SomethingElse - going for 221 possibilities [User: HOST-NAME\XYZZY]: Id OtherData 5878 C 5968 X 6732 V [many more lines like this] ''' Some hunting around, and I found this: C:\Program Files\Informix\Client-SDK\bin>esql IBM Informix CSDK Version 2.80, IBM Informix-ESQL Version 9.52.TC1 Not sure what IDS is... the Informix Server version is: 9.3 FC3, according to the DBA guy. Thanks much.

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Re: Finding the name of a class
by John Salerno Aug. 1, 2006

Aug. 1, 2006

Tim Chase wrote: > While this is surely true, would somebody explain why I had such trouble > finding this? I think __name__ is an attribute of the class itself, not the instance: >>> class Foo(object): pass >>> f = Foo() >>> f.__name__ Traceback (most recent call last): File "<pyshell#4>", line 1, in -toplevel- f.__name__ AttributeError: 'Foo' object has no attribute '__name__' >>> Foo.__name__ 'Foo'

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Re: fast pythonic algorithm question
by Diez B. Roggisch Aug. 1, 2006

Aug. 1, 2006

>> I'd say it is as fast as it can get - using hashing for lookups is O >> (n) in > > > I know you meant O(1) for hash lookups, but just in case anyone is > confused, I figured I'd correct this. Ooops. Thanks. Diez

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