🌐 Mailman 3 October 2004 - Python-list - python.org

WeakValueDictionary
by Bryan Oct. 3, 2004

Oct. 3, 2004

there must be something i don't understand about WeakKeyDictionary and WeakValueDictionary. i had expected the last line to be empty because i thought i deleted the last strong reference to variable "a". what am i misunderstanding? >>> d = weakref.WeakValueDictionary() >>> a = A() >>> d[1] = a >>> d.items() [(1, <__main__.A instance at 0x0116BC60>)] >>> del a >>> d.items() [(1, <__main__.A instance at 0x0116BC60>)] >>> thanks, bryan

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simple socket code
by Nikola Bjelicic Oct. 3, 2004

Oct. 3, 2004

**** Post for FREE via your newsreader at post.usenet.com **** Please help me to put some content on apache + DAV server, whas wrong? [code] import socket, os, stat file=open('/home/nikola/somefile','rb') lenght=os.fstat(file.fileno())[stat.ST_SIZE] print lenght headers={} headers['Host']='localhost' headers['Authorization']='Basic bmlrb2xhOnRlc3Q=' headers['Accept-Encoding']='identity' headers['Content-Type']='application/octet-stream' headers['Content-Encoding']='None' headers['Content-Lenght']=lenght data = '%s %s %s\r\n' %('PUT', '/dav/test1','HTTP/1.1') for header, value in headers.items(): data += '%s: %s\r\n'%(header,value) data += '\r\n' sock=socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.connect(('localhost', 80)) sock.send(data) sock.send(file.read()) #doesnt work why? response=sock.recv(2000) print response sock.close() [/code] -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= *** Usenet.com - The #1 Usenet Newsgroup Service on The Planet! *** http://www.usenet.com Unlimited Download - 19 Seperate Servers - 90,000 groups - Uncensored -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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Re: Using python to convert PDF document to MSWord documents
by Steve Holden Oct. 3, 2004

Oct. 3, 2004

Timothy Grant wrote: > ----- Original Message ----- > From: JEET <hjeet_in(a)yahoo.com> > Date: Tue, 28 Sep 2004 17:13:17 +0100 (BST) > Subject: Using python to convert PDF document to MSWord documents > To: python-list(a)python.org > > > > > Hello All, > > Can anyone please suggest me if there any python modules available to > convert PDF document to MSWord documents. If not then can you please > suggest how can i acheive this. > > Many thanks in advance, > One of the problems with such a module would be that PDF is primarily a display format, and so the structure of the file doesn't necessarily conform with the structure of the document. regards Steve

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How can I code to get more than One value from checkbox?
by s4046441＠student.uq.edu.au Oct. 3, 2004

Oct. 3, 2004

Hi, I'm a newbie that just started to learn python, html and etc. I have some questions to ask and hope that someone can help me on. I'm trying to code a python script (with HTML) to get values from a html form that consists of about 10 checkbox and a textbox where user have to key in a value to perform a search. >From python tutors, I learned that I have to use the following method: ### qtype = data.getfirst('qtype') ---- checkbox name qtext = data.getfirst('qtext', '') ---- textbox name ### but I don't really know how to do it. Should I use qtype = data.getlist('qtype') to get the value from the checkbox and how to? Currently, my method required me to type in every possible combination of the checkbox and I know that this is wrong. I wanna to include %(qtype) in my query statement so that the script will look for the value that contain qtype everytime a form is processs but the way I'm doing now is wrong. query = "select %(qtype)s from shot_descriptions where shot_number=%(qtext)s", qtype, qtext Thus, can someone help me on this. Thank you for any help. Shufen

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proposed struct module format code addition
by Josiah Carlson Oct. 3, 2004

Oct. 3, 2004

Good day everyone, I have produced a patch against the latest CVS to add support for two new formatting characters in the struct module. It is currently an RFE, which I include a link to at the end of this post. Please read the email before you respond to it. Generally, the struct module is for packing and unpacking of binary data. It includes support to pack and unpack the c types: byte, char, short, long, long long, char[], *, and certain variants of those (signed/unsigned, big/little endian, etc.) Purpose ------- I had proposed two new formatting characters, 'g' and 'G' (for biGint or lonG int). There was one primary purpose, to offer users the opportunity to specify their own integer lengths (very useful for cryptography, and real-world applications that involve non-standard sized integers). Current solutions involve shifting, masking, and multiple passes over data. There is a secondary purpose, and that is that future n-byte integers (like 16-byte/128-bit integers as supported by SSE2) are already taken care of. It also places packing and unpacking of these larger integers in the same module as packing and packing of other integers, floats, etc. This makes documentation easy. Functionality-wise, it merely uses the two C functions _PyLong_FromByteArray() and _PyLong_ToByteArray(), with a few lines to handle interfacing with the pack and unpack functions in the struct module. An example of use is as follows: >>> struct.pack('>3g', -1) '\xff\xff\xff' >>> struct.pack('>3g', 2**23-1) '\x7f\xff\xff' >>> struct.pack('>3g', 2**23) Traceback (most recent call last): File "<stdin>", line 1, in ? OverflowError: long too big to convert >>> struct.pack('>3G', 2**23) '\x80\x00\x00' It follows the struct module standard 'lowercase for signed, uppercase for unsigned'. Arguments --------- There seem to be a few arguments against its inclusion into structmodule.c... Argument: The size specifier is variable, so you must know the size/magnitude of the thing you are (un)packing before you (un)pack it. My Response: All use cases I have for this particular mechanism involve not using 'variable' sized structs, but fixed structs with integers of non-standard byte-widths. Specifically, I have a project in which I use some 3 and 5 byte unsigned integers. One of my (un)pack format specifiers is '>H3G3G', and another is '>3G5G' (I have others, but these are the most concise). Certainly this does not fit the pickle/cPickle long (un)packing use-case, but that problem relies on truely variable long integer lengths, of which this specifier does not seek to solve. Really, the proposed 'g' and 'G' format specifiers are only as variable as the previously existing 's' format specifier. Argument: The new specifiers are not standard C types. My Response: Certainly they are not standard C types, but they are flexible enough to subsume all current integer C type specifiers. The point was to allow a user to have the option of specifying their own integer lengths. This supports use cases involving certain kinds of large dataset processing (my use case, which I may discuss after we release) and cryptography, specifically in the case of PKC... while 1: blk = get_block() iblk = struct.unpack('>128G', blk)[0] uiblk = pow(iblk, power, modulous) write_block(struct.pack('>128G', uiblk)) The 'p' format specifier is also not a standard C type, and yet it is included in struct, specifically because it is useful. Argument: You can already do the same thing with: pickle.encode_long(long_int) pickle.decode_long(packed_long) and some likely soon-to-be included additions to the binascii module. My Response: That is not the same. Nontrivial problems require multiple passes over your data with multiple calls. A simple: struct.unpack('H3G3G', st) becomes: pickle.decode_long(st[:2]) #or an equivalent struct call pickle.decode_long(st[2:5]) pickle.decode_long(st[5:8]) And has no endian or sign options, or requires the status quo using of masks and shifts to get the job done. As previously stated, one point of the module is to reduce the amount of bit shifting and masking required. Argument: We could just document a method for packing/unpacking these kinds of things in the struct module, if this really is where people would look for such a thing. My Response: I am not disputing that there are other methods of doing this, I am saying that the struct module includes a framework and documentation location that can include this particular modification with little issue, which is far better than any other proposed location for equivalent functionality. Note that functionality equivalent to pickle.encode/decode_long is NOT what this proposed enhancement is for. Argument: The struct module has a steep learning curve already, and this new format specifier doesn't help it. My Response: I can't see how a new format specifier would necessarily make the learning curve any more difficult, if it was even difficult in the first place. Why am I even posting --------------------- Raymond has threatened to close this RFE due to the fact that only I have been posting to state that I would find such an addition useful. If you believe this functionality is useful, or even if you think that I am full of it, tell us: http://python.org/sf/1023290 - Josiah

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Re: (no subject)
by Steve Holden Oct. 2, 2004

Oct. 2, 2004

Campbell Kwok wrote: > Hi, I am trying to write a program for my school homework and I'm a > little stuck. The homework have to do with barcodes and I need to read > the barcode, then add up all the odd number positions(eg a barcode of > 123456789012, then the odd is 1,3,5,7,9,1) I do not know how to get the > odd number positions out of that str of numbers. Please help me > > _________________________________________________________________ > Scan and help eliminate destructive viruses from your inbound and > outbound e-mail and attachments. > http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU=ht… > Start enjoying all the benefits of MSN® Premium right now and get the > first two months FREE*. > for i in range(half-length): print 2*(i+1) regards Steve

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Wiki on Python and Web Programming?
by Tim Roberts Oct. 2, 2004

Oct. 2, 2004

Isn't there a wiki somewhere that compares and contrasts the various web architectures available for Python? I've realized that I have built web sites based on at least 4 of the popular contenders, and my experiences might be valuable to others. I thought I remembered a comparison wiki, but I can't find it now. -- - Tim Roberts, timr(a)probo.com Providenza & Boekelheide, Inc.

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Exception feature creep! (was: re-entering in the normal flow after an exception is raised)
by finite.automaton＠gmail.com Oct. 2, 2004

Oct. 2, 2004

In a recent post, Michele Simionato asked about resumable (or re-entrant) exceptions, the basic idea being that when raised and uncaught, these exceptions would only propagate backwards through a limited number of frames before being implicitly ignored. Alex Martelli pointed out that resumable exceptions are difficult to implement, and that the need for them isn't pressing because it's pretty easy to write a program with explicit error handling that works just fine, citing Bjarne Stroustrup's thoughts on the same topic for C++. This is probably quite right. Nonetheless, I tried to write some demo code that implemented resumable exceptions, but ran face-first into a brick wall: I couldn't find any way to manipulate the call stack (to execute code in a frame other than the current one) What if exceptions were given more control? Proposal: 1. Call a __raise__ method in the exception when raised 2. Call an __uncaught__ method in every frame for which the exception is not handled by an except clause. __uncaught__ would decide whether or not to continue to propagate the exception to the next frame. If __uncaught__ decides to abort the exception, then the calling statement is aborted/ignored--- the implicit equivalent of: try: do_something() except: pass Anyway, this is just idle speculation. I don't really see a need for it, but it's interesting to ponder. Here are some hypothetical uses: 1. An exception that propagates only n frames: class QuietException(Exception): def __init__(self, n): Exception.__init__(self) self.n = n def __raise__(self): self.counter = self.n def __uncaught__(self): if self.counter > 0: self.counter -= 1 return True else: return False 2. An exception that keeps a traceback as it goes: class TracingException(Exception): def __raise__(self): self.traceback = [] def __uncaught__(self): self.traceback.append(sys._getframe(1)) ... try: foo() except TracingException, e: # isn't this more elegant than sys.last_traceback? import traceback traceback.print_tb(e.traceback) 3. An exception that resumes execution if some global FAULT_TOLERANT is true: class FaultTolerantException(Exception): def __uncaught__(self): return not FAULT_TOLERANT

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Re: (no subject)
by Paul Rubin Oct. 2, 2004

Oct. 2, 2004

"Campbell Kwok" <forsberg5(a)hotmail.com> writes: > Hi, I am trying to write a program for my school homework and I'm a > little stuck. The homework have to do with barcodes and I need to read > the barcode, then add up all the odd number positions(eg a barcode of > 123456789012, then the odd is 1,3,5,7,9,1) I do not know how to get > the odd number positions out of that str of numbers. Please help me If x is a string, then x[0] is the first character, x[1] is the second character, and so forth.

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(no subject)
by Campbell Kwok Oct. 2, 2004

Oct. 2, 2004

Hi, I am trying to write a program for my school homework and I'm a little stuck. The homework have to do with barcodes and I need to read the barcode, then add up all the odd number positions(eg a barcode of 123456789012, then the odd is 1,3,5,7,9,1) I do not know how to get the odd number positions out of that str of numbers. Please help me _________________________________________________________________ Scan and help eliminate destructive viruses from your inbound and outbound e-mail and attachments. http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU=ht… Start enjoying all the benefits of MSN® Premium right now and get the first two months FREE*.

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