Re: catch argc-argv
John Machin wrote:
>Duncan Booth wrote:
>
>
>>John Machin wrote:
>>
>>
>>
>>
So, my question is: does the Python API containe fonctions like
'get_argc()' and 'get_argv()' ?
>>>If you can't see them in the documentation, they aren't there. If they
>>>aren't there, that's probably for a good reason -- no demand, no use
>>>case.
>>>
>>>
>>>
>>>
>>Leaving aside whether or not there is a use-case for this, the reason they
>>aren't there is that they aren't needed.
>>
>>
>
>"no use-case" == "no need" in my book
>
>
>
>>As the OP was already told, to
>>access argv, you simply import the 'sys' module and access sys.argv.
>>
>>
>
>Simple in Python, not in C.
>
>
>
>>There are apis both to import modules and to get an attribute of an
>>existing Python object.
>>
>>
>
>I know that; my point was why should you do something tedious like that
>when you shouldn't be interested in accessing sys.argv from a C
>extension anyway.
>
>
>
>> So all you need is something like (untested):
>>
>>PyObject *sys = PyImport_ImportModule("sys");
>>PyObject *argv = PyObject_GetAttrString(sys, "argv");
>>int argc = PyObject_Length(argv);
>>if (argc != -1) {
>> ... use argc, argv ...
>>}
>>Py_DECREF(argv);
>>Py_DECREF(sys);
>>
>>
I understand all the good arguments explained before, and I am agree
with them.
Nevertheless, I implement Python bindings from a generic parallel
framework and a new application based on this framework needs to call a
kind of initilization class : the constructor arguments are argc and
argv... Then, the previous solution can be a work around to test some
behavours of my bindings.
Thanks for your answers ;-)
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Re: Extensions on Linux: import without underscore?
On Monday 20 June 2005 06:39 am, Kent Johnson wrote: > Terry Hancock wrote: > > Okay, you may want a more elegant way to do this and other people > > have already responded to that point, but you do at least know you > > can just give it a new name: > > > > import _bright > > bright = _bright > > or more idiomatically and without adding _bright to the namespace: > import _bright as bright Um, yeah, I knew that. Really I did. ;-) -- Terry Hancock ( hancock at anansispaceworks.com ) Anansi Spaceworks http://www.anansispaceworks.com -- http://mail.python.org/mailman/listinfo/python-list
Re: references/addrresses in imperative languages
Dear Andrea Griffini, Thanks for explaning this tricky underneath stuff. Xah [EMAIL PROTECTED] ∑ http://xahlee.org/ Andrea Griffini wrote: > On Sun, 19 Jun 2005 22:25:13 -0500, Terry Hancock > <[EMAIL PROTECTED]> wrote: > > >> PS is there any difference between > >> t=t+[li] > >> t.append(li) > > > >No, but > > Yes, a big one. In the first you're creating a new list > and binding the name t to it, in the second you're extending > a list by adding one more element at the end. > To see the difference: > > >>> a = [1,2,3] > >>> b = a > >>> a = a + [4] > >>> print a > [1, 2, 3, 4] > >>> print b > [1, 2, 3] > >>> > >>> a = [1,2,3] > >>> b = a > >>> a.append(4) > >>> print a > [1, 2, 3, 4] > >>> print b > [1, 2, 3, 4] > >>> > > Andrea -- http://mail.python.org/mailman/listinfo/python-list
regarding cache clearing header in python cgi
Dear All,
In Php the following headers base we can clean
the cache in the url "header('Cache-Control:
no-store, no-cache, must-revalidate'); "
I want to know Php equivalent headers in Python-cgi
If anybody know regarding this kindly mail me.
regards,
Prabahar
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Re: Overcoming herpetophobia (or what's up w/ Python scopes)?
kj wrote: > I am hoping that it may be better this time around. For one thing, > like Perl, Python was then (and maybe still is) a "work in progress." > So I figure that Python scoping may have improved since then. Even > if not, I think that Python is mature enough by now that adequate > alternatives must have been devised for the Perlish features that > I missed during my first attempt. I don't know of any tutorials, but given that you're familiar with the concept of closures and scopes I don't think you really need one to understand what Python does and doesn't provide. Python does allow you to refer to variables in lexically enclosing scopes, and it closes over them properly. Python (annoyingly) does _not_ provide a way to write to the closed-over variable. Assignments always go into the local scope. There is a "global" statement that allows you to "target" the module scope; one can imagine an analagous statement that allows you to target an intervening scope, but it doesn't exist. Some (incorrectly) interpret this to mean that the variable isn't actually closed-over. The following code executes without errors, which shows that the closure really does refer to the outer variable, and not some constant copy: def closure_test(): def make_closure(): def closure(): # a += 1 # this will give you an unbound local error at runtime return a return closure fn = make_closure() a = 1 assert fn() == a a = 2 assert fn() == a closure_test() The canonical way around this is to add a layer of indirection -- isn't that always the solution? def closure_test2(): def make_closure(): def closure(): a[0] += 1 return a[0] return closure fn = make_closure() a = [1] assert fn() == 2 assert fn() == 3 closure_test2() p -- http://mail.python.org/mailman/listinfo/python-list
A tool for Python - request for some advice
First I have to admit that my English isn't good enough. I'm still studying and sometimes I just can't express what I want to express. A few weeks ago I've written 'Python Builder' - a bash script that allows anyone to download, compile (with flags given by user) and install Python and some external modules (e.g. wxPython, PyGTK, Numeric...). I use Python every day and when new version of Python (or some external module) is released, I want to check if my projects will run on this new version (sometimes I want to know if my projects will run on specific combination of older Python and some older external modules...). It happens four - five times a year. Frequently not enough to memorize all commands used to configure, compile and install all of this software (so I have to read documentation every time I'm doing it) - but frequently enough to consume considerable amounts of my working time. So I thought that writing a script to do it all automatically (download sources, unpack them, configure them, compile them and then install them; all of this with options given by me - the user) would be a good idea. (It's not about using emerge, get-apt or some another tool of this kind. My need is very special - I want to have Python, it's modules and sometimes documentation installed in particular place; usually somewhere in my home directory. My script installs some additional scripts which I can use to run Python. These additional scripts have properly set LD_LIBRARY_PATH so they are able to run Python and external modules that require libraries installed in non-standard locations.) I've written this script in bash, because I thought it would be better to have a script which would run in environment without Python (it all was about installing Python anyway!). I used bash, dialog, wget... And now someone suggested, that I shuld use Python. That using Python would lead to clearer and - probably - smaller code. (I have to admit it - my code in bash is just messy.) And now I'm considering this idea. Python is already present on (almost?) every distribution today, so why worry about it's presence? Writing in Python would lead to easier i18n (for now it's all in Polish...) and to easier implementation of future enhancements (due to language's features and much more clearer coding style in Python). Well - I've already found it hard to implement new features in pure bash. But, on the other hand, I'm thinking that writing in bash is more universal solution. I mean that requirements to run bash scripts are lower than requirements to run Python scripts. Could this requirements be decisive for some users (or is it only my imagination)? Sometimes users just have no access to Python (e.g. LFS, some stages of Gentoo, some rescue and specialized distros). And there's also something more. For now "Python Builder" works in text mode. It was written in bash and I assumed it should be some kind of "basic" tool - so text mode and bash seemed to be the best choice. But if I rewrote all code in Python I could make some GUI. It could works even better - I could easily check if GUI mode is available and run in proper (GUI or text) mode. But is GUI needed by people who just want it to do it's job and quit? Well, what do you think? -- http://mail.python.org/mailman/listinfo/python-list
Re: references/addrresses in imperative languages
SM Ryan wrote: > "Kaz Kylheku" <[EMAIL PROTECTED]> wrote: > # SM Ryan wrote: > # > # easy way to see this, is to ask yourself: how come in mathematics > # > # there's no such thing as "addresses/pointers/references". > # > > # > The whole point of Goedelisation was to add to name/value references into > # > number theory. > # > # Is that so? That implies that there is some table where you can > # associate names (or whatever type of locators: call them pointers, > # whatever) with arbitrary values. But in fact that's not the case. > > Do you really believe the Goedel number of a statement is the statement > itself? Is everything named Kaz the same as you? The Goedel number is a representation of the statement in a way that the name Kaz isn't a representation of me. You cannot identify parts of the name Kaz with parts of me; there is no isomorphism there at all. I am not the translated image of the name Kaz, nor vice versa. A Goedel number isn't anything like a name or pointer. It's an encoding of the actual typographic ``source code'' of the expression. There is nothing external to refer to other than the encoding scheme, which isn't particular to any given Goedel number. The encoding scheme is shallow, like a record player; it doesn't contribute a significant amount of context. If I decode a Goedel number, I won't have the impression that the formula was hidden in the numbering scheme, and the Goedel number simply triggered it out like a pointer. No, it will be clear that each piece of the resulting formula is the direct image of some feature of the Goedel number. -- http://mail.python.org/mailman/listinfo/python-list
Re: references/addrresses in imperative languages
SM Ryan wrote: > "Kaz Kylheku" <[EMAIL PROTECTED]> wrote: > # SM Ryan wrote: > # > # easy way to see this, is to ask yourself: how come in mathematics > # > # there's no such thing as "addresses/pointers/references". > # > > # > The whole point of Goedelisation was to add to name/value references into > # > number theory. > # > # Is that so? That implies that there is some table where you can > # associate names (or whatever type of locators: call them pointers, > # whatever) with arbitrary values. But in fact that's not the case. > > Do you really believe the Goedel number of a statement is the statement > itself? Is everything named Kaz the same as you? The Goedel number is a representation of the statement in a way that the name Kaz isn't a representation of me. You cannot identify parts of the name Kaz with parts of me; there is no isomorphism there at all. I am not the translated image of the name Kaz, nor vice versa. A Goedel number isn't anything like a name or pointer. It's an encoding of the actual typographic ``source code'' of the expression. There is nothing external to refer to other than the encoding scheme, which isn't particular to any given Goedel number. The encoding scheme is shallow, like a record player; it doesn't contribute a significant amount of context. If I decode a Goedel number, I won't have the impression that the formula was hidden in the numbering scheme, and the Goedel number simply triggered it out like a pointer. No, it will be clear that each piece of the resulting formula is the direct image of some feature of the Goedel number. -- http://mail.python.org/mailman/listinfo/python-list
after transfer of data from MS-outlook(mail ids) to application, mail ids are consisting of strange characters
Hello all,the following problem i encountered while transferring data(mail ids) from MS-outlook to one application.Some mail ids after came into the application looked as strange characters.Eg are [Å@ [Å. [Å,©Ä@ ©Ä. ©Ä etc.I thought these are the Ascii characters but i'm not quite sure about this.And also each mail id following a certain format as you can observe from the above mail ids.Only one string is repeating in all the 3 parts of the mail id.Is there any procedure to convert these characters to the plain letters.I hope somebody will help me in this regard to unfold this mystery.Bye. Best Regards, Vamsi -- http://mail.python.org/mailman/listinfo/python-list
Re: references/addrresses in imperative languages
"Kaz Kylheku" <[EMAIL PROTECTED]> wrote: # SM Ryan wrote: # > # easy way to see this, is to ask yourself: how come in mathematics # > # there's no such thing as "addresses/pointers/references". # > # > The whole point of Goedelisation was to add to name/value references into # > number theory. # # Is that so? That implies that there is some table where you can # associate names (or whatever type of locators: call them pointers, # whatever) with arbitrary values. But in fact that's not the case. Do you really believe the Goedel number of a statement is the statement itself? Is everything named Kaz the same as you? -- SM Ryan http://www.rawbw.com/~wyrmwif/ Sothat would make Bethany part black? -- http://mail.python.org/mailman/listinfo/python-list
Re: regarding cache clearing header in python cgi
Dear All,
In Php the following headers base we can clean
the cache in the url
"header('Cache-Control: no-store, no-cache,
must-revalidate'); "
I want to know Php equivalent headers in Python-cgi
If any know regarding this kindly mail me.
regards,
Prabahar
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Using code objects?
Using code objects?
===
As an OO exercise I have a factory pattern that returns class objects that
each have an "action" method. ClassObj.action() in turn returns a code
object in my recursive process loop.
I create the code objects as a one time step outside my factory pattern and
potential class definitions, then reference them in my potential classes
which seems to work as expected.
When I create the code objects though, it seems a couple different ways work
and I'm wondering which is better and why (or is there a more correct
technique in this situation)?
The two different ways are illustrated below:
Python 2.4.1 (#2, Mar 31 2005, 00:05:10)
[GCC 3.3 20030304 (Apple Computer, Inc. build 1666)]
Type "help", "copyright", "credits" or "license" for more information.
>>> def foo(st):
... print st
...
>>> exp1 = 'foo("#expersion 1#")'
>>> exp2 = 'foo("#expersion 2#")'
>>> obj1 = compile(exp1, 'whatever', 'single')
>>> exec obj1
#expersion 1#
>>> obj2 = compile(exp2, 'whatever', 'exec')
>>> exec obj2
#expersion 2#
>>>
Thank you,
Lee C
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Re: references/addrresses in imperative languages
Lawrence DâOliveiro wrote: > In article <[EMAIL PROTECTED]>, > "Xah Lee" <[EMAIL PROTECTED]> wrote: > > >A[n] easy way to see this, is to ask yourself: how come in mathematics > >there's no such thing as "addresses/pointers/references". > > Yes there are such things in mathematics, though not necessarily under > that name. > > For instance, in graph theory, edges can be considered as "pointers". > After all, make a change to a node, and that change is visible via all > edges pointing to that node. Oh yeah, by the way, note how such destructive changes to a variable become whole-environment derivations in the discipline of proving the correctness of imperative programs. E.g. say you have this assignment: x <- x + 1 and you want to deduce what preconditions must exist in order for the desired outcome x = 42 to be true after the execution of the statement. What do you do? You pretend that the program is not modifying a variable in place, but rather manufacturing a new environment out of an old one. In the new environment, the variable X has a value that is one greater than the corresponding variable in the old environment. To distinguish the two variables, you call the one in the old environment X' . You can then transform the assignment by substituting X' for X in the right hand side and it becomes x <= x' + 1 and from that, the precondition x' = 41 is readily deduced from the x = 42 postcondition. Just to be able to sanely reason about the imperative program and its destructive variable assignment, you had to nicely separate past and future, rename the variables, and banish the in-place modification from the model. -- http://mail.python.org/mailman/listinfo/python-list
Re: references/addrresses in imperative languages
SM Ryan wrote: > # easy way to see this, is to ask yourself: how come in mathematics > # there's no such thing as "addresses/pointers/references". > > The whole point of Goedelisation was to add to name/value references into > number theory. Is that so? That implies that there is some table where you can associate names (or whatever type of locators: call them pointers, whatever) with arbitrary values. But in fact that's not the case. > Thus Goedel was able to add back pointers contrary to the > set hierarchy of the theory of types and reintroduce Russel's paradox. Nope. Goedel didn't add anything, he just revealed what was already there: that you can have statements of number theory, well-formed formulas constructed out of existing operators without any backpointer tricks, which have true interpretations, but are not theorems. Everything in a Goedel's string can be recursively expanded to yield an ordinary formula! There is no infinite regress, no unchased embedded pointer-like things left behind. Self-reference is achieved using two tricks: Goedel numbering, and indirect reference. Godel numbering allows a formula to talk about formulas, by way of embedding their Godel numbers, and translating formula-manipulations into arithmetic manipulations (of interest are finite ones that will nicely unfold into finite formulas). In essence that which used to be ``code'' can be now treated as ``data''', and operations on code (logical derivations) become arithmetic operations on data. Indirect reference is needed because a formula G's Goedel number cannot be inserted into itself directly. If you start with a formula G which has some free variable V, and then produce some new formula by substituting G's Goedel number into it directly for occurences of V, you no longer have G but that other formula. You want whatever comes out to be G, and so the input formula, the one with the free variable, cannot be G, but perhaps a close relative which either talks about G, or whose constituent formulas cleverly end up talking about G after the substitution takes place. Instead of a direct (Goedel number) reference, you can insert into a formula some /procedure/ for making that formula's Goedel number out of another formula's Goedel number and talk about it that way. As an example, instead of saying ``here is a number'' by inserting its literal digits, you can say ``the number that results by applying this formula to this other number''. For instance, instead of writing the number 4 we can write successor(3). or 2 + 2. We explicitly mention some other number, and say how 4 is constructed out of it. Douglas Hofstadter exposition of all this is very good. To allow the formula G to mention its own Goedel number, Douglas Hofstadter uses another formula which he calls U, the ``uncle''. The trick is that: the procedure for making G's Goedel number out of U's number is the arithmetic equivalent of the same procedure that's used to substitute the Goedel number of U for the free variable in U itself. So as U (the formula) is treated by substituting its own Godel number for its one and only free variable, it produces G, and, at the same time, the arithmetic version of that substitution, fully contained inside the U formula itself, turns the now substituted copy of U into G also. U contains the fully expanded ``source code'' for the arithmetic version of the free-variable substitution procedure, and it contains a free variable representing the arithmetic version of the formula on which that algorithm is to be done. As that free variable within U is replaced by the Goedel number U, the overall formula becomes G, and the embedded free-variable-replacement procedure is instantiated concretely over U's Goedel number, so it becomes a constant, unparameterized calculation that produces G's Goedel number. Voila, G contains a procedure that computes the arithmetic object (Goedel number) that represents G's ``source code'' (the symbolic formula), out of the embedded number representing U's source code. Using that giant formula, G can assert things about itself, like ``I am not a theorem'' (i.e. ``there exists no integer representing the Goedel numbers of a list of true statements that represent a derivation deducing myself as the conclusion''). There are no name references or pointers or anything. All the functions are primitive recursive, and so can be expanded into finite-length formulas which contain only numbers and operators and variables---dummy ones that are bound to existential quantifiers, not to concrete values some external name/value table. -- http://mail.python.org/mailman/listinfo/python-list
Re: multi threading and win9x
[Timothy Smith] > i want to run my sql statements on a seperate thread to prevent my app > from stop responding to input (atm is says "not responding" under > windows until the sql is finished) > but i'm hesitant because i have to still support win9x and i'm not sure > how well this will play. All versions of Windows >= Win95 use threads heavily, have very solid thread support, and the Win32 API was thread-aware from the start Thread _scheduling_ is pretty bizarre <= WinME, but process scheduling is too. Don't try to use hundreds of threads <= WinME and you should be fine. -- http://mail.python.org/mailman/listinfo/python-list
multi threading and win9x
i want to run my sql statements on a seperate thread to prevent my app from stop responding to input (atm is says "not responding" under windows until the sql is finished) but i'm hesitant because i have to still support win9x and i'm not sure how well this will play. -- http://mail.python.org/mailman/listinfo/python-list
Re: Tuple Unpacking in raise
Thank you Steven and Konstantin, that clears things up. Sometimes I forget how incomplete my Python Essential Reference is. James On Monday 20 June 2005 05:40 pm, Steven Bethard wrote: > Well, it's not a bug, because that's what the documentation says it'll do: > > "The second object is used to determine the exception value: If it is an > instance of the class, the instance becomes the exception value. If the > second object is a tuple, it is used as the argument list for the class > constructor; if it is None, an empty argument list is used, and any > other object is treated as a single argument to the constructor."[1] > > In the example above (as well as almost all code), there's no need to > use the two argument version of raise. You can simply write: > > raise MyErr(sometup) > > If you need the three argument version of raise, I believe you can still > write it as: > > raise MyErr(sometup), None, tb > > Note that Guido has mentioned a few times that in Python 3.0, he wants > tracebacks to be attributes of the Exception objects so that all raise > statements are like the one argument version. > > STeVe > > P.S. If you insist on using the two argument version of raise, you can > do it like this: > > py> class E(Exception): > ... def __init__(self, atup): > ... Exception.__init__(self, "Error with %s-%s" % atup) > ... > py> raise E, ((1, 2),) > Traceback (most recent call last): >File "", line 1, in ? > E: Error with 1-2 > > But that seems a lot less elegant than simply using the one argument > version. > > [1] http://docs.python.org/ref/raise.html -- James Stroud UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
getting list of all available modules
I note that the help() function of interactive python can determine all available modules: [EMAIL PROTECTED] ~]$ python Python 2.4 (#1, Mar 31 2005, 15:26:02) [GCC 3.2.3 (Debian)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> help() [...] help> modules Please wait a moment while I gather a list of all available modules... BaseHTTPServer bisect linuxaudiodev shelve Bastion bsddb (package) locale shlex BicycleRepairMan_Idle cPickle logging (package) shutil CDROM cStringIO macpath signal CGIHTTPServer calendarmacurl2path site Canvas cgi mailbox smtpd ConfigParsercgitb mailcap smtplib [...] I want to do the same (get all such modules in a python list); how can I do so? Or where is the code for the REPL for help() itself so I can find out myself? This is to build a code introspection tool BTW. Thanks, -- Benjamin Rutt -- http://mail.python.org/mailman/listinfo/python-list
Re: reading a list from a file
:-/ You're right! -- http://mail.python.org/mailman/listinfo/python-list
Re: Tuple Unpacking in raise
On 6/21/05, Steven Bethard <[EMAIL PROTECTED]> wrote: > James Stroud wrote: > P.S. If you insist on using the two argument version of raise, you can > do it like this: > > py> class E(Exception): > ... def __init__(self, atup): > ... Exception.__init__(self, "Error with %s-%s" % atup) > > But that seems a lot less elegant than simply using the one argument > version. Another workaround would be to use __init__(self, *atup), but raising an explicitly constructed exception is preferable (IMO). - kv -- http://mail.python.org/mailman/listinfo/python-list
Re: Tuple Unpacking in raise
On 6/21/05, James Stroud <[EMAIL PROTECTED]> wrote: > Hello All, > > Is this a bug? No, it works as documented. You should've consulted language reference: http://docs.python.org/ref/raise.html - kv -- http://mail.python.org/mailman/listinfo/python-list
Re: Tuple Unpacking in raise
James Stroud wrote: > Hello All, > > Is this a bug? Why is this tuple getting unpacked by raise? Am I missing some > subtle logic? Why does print not work the same way as raise? Both are > statements. Why does raise need to be so special? > > py> sometup = 1,2 > py> print sometup > (1, 2) > py> print 1,2,3, sometup > 1 2 3 (1, 2) > py> class MyErr(Exception): > ... def __init__(self, atup): > ... Exception.__init__(self, "Error with %s-%s" % atup) > ... > py> raise MyErr, sometup > Traceback (most recent call last): > File "", line 1, in ? > TypeError: __init__() takes exactly 2 arguments (3 given) > py> e = MyErr(sometup) > py> print e > Error with 1-2 Well, it's not a bug, because that's what the documentation says it'll do: "The second object is used to determine the exception value: If it is an instance of the class, the instance becomes the exception value. If the second object is a tuple, it is used as the argument list for the class constructor; if it is None, an empty argument list is used, and any other object is treated as a single argument to the constructor."[1] In the example above (as well as almost all code), there's no need to use the two argument version of raise. You can simply write: raise MyErr(sometup) If you need the three argument version of raise, I believe you can still write it as: raise MyErr(sometup), None, tb Note that Guido has mentioned a few times that in Python 3.0, he wants tracebacks to be attributes of the Exception objects so that all raise statements are like the one argument version. STeVe P.S. If you insist on using the two argument version of raise, you can do it like this: py> class E(Exception): ... def __init__(self, atup): ... Exception.__init__(self, "Error with %s-%s" % atup) ... py> raise E, ((1, 2),) Traceback (most recent call last): File "", line 1, in ? E: Error with 1-2 But that seems a lot less elegant than simply using the one argument version. [1] http://docs.python.org/ref/raise.html -- http://mail.python.org/mailman/listinfo/python-list
Re: reading a list from a file
On 6/20/05, David Bear <[EMAIL PROTECTED]> wrote:
> I have a file that contains lists -- python lists. sadly, these
> are not pickled. These are lists that were made using
> a simple print list statement.
Sad, indeed. But what kind of objects they held? Only ints? Ints and
strings? Arbitrary objects?
>
> Is there an easy way to read this file into a list again?
> I'm thinking I would have to
>
> read until char = '['
>read until char = " ' "
>
> Well, reading character by char until I have the list and then
> parse it all myself.
At least you can leave tokenizing to python lib:
>>> import tokenize, token, pprint
>>> token_names = dict([
... (value, name) for (name, value)
... in token.__dict__.iteritems()
... if isinstance(value, int)])
>>> tokens = tokenize.generate_tokens(
... iter(['[1, 2, "ab\'c,d"]']).next)
>>> pprint.pprint([(token_names[t[0]], t[1]) for t in tokens])
[('OP', '['),
('NUMBER', '1'),
('OP', ','),
('NUMBER', '2'),
('OP', ','),
('STRING', '"ab\'c,d"'),
('OP', ']')]
- kv
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Re: sudoku dictionary attack
"Oliver Albrecht" <[EMAIL PROTECTED]> wrote ... > Has some one an sodoku-task-generator? Sudoku puzzles can be generated (and solved) online at http://act365.com/sudoku/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Want to learn a language - is Python right?
Python will help you as a novice for these reasons: 1. Help you to learn programming concepts and develop good habits. 2. Powerful Standard Library to help you do more advanced things. 3. Smooth, shallow learning curve, e.g. hello world is: print "Hello World" So you can do simple things in python with minimal learning. 4. Excellent, friendly, patient, helpful user base. 5. Code is inherently more maintainable than other languages. 6. comp.lang.python In short, you have come to the right place. I have used many programming languages (C, Java, Fortran, Python, Perl, just to name the more famous ones) and python takes the cake as a general purpose programming language. By the way, ignore any posts talking about speed of execution. This is generally a non-issue for new programmers. If you want your code to run faster, buy a faster computer. James On Monday 20 June 2005 07:47 am, Aziz McTang wrote: > What I'm looking for is more to learn one good, comprehensive > programming language well than several approximately on an ad hoc > basis. What I also failed to mention is the desire to develop my > presently limited computer skills a lot further. -- James Stroud UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
Tuple Unpacking in raise
Hello All, Is this a bug? Why is this tuple getting unpacked by raise? Am I missing some subtle logic? Why does print not work the same way as raise? Both are statements. Why does raise need to be so special? py> sometup = 1,2 py> print sometup (1, 2) py> print 1,2,3, sometup 1 2 3 (1, 2) py> class MyErr(Exception): ... def __init__(self, atup): ... Exception.__init__(self, "Error with %s-%s" % atup) ... py> raise MyErr, sometup Traceback (most recent call last): File "", line 1, in ? TypeError: __init__() takes exactly 2 arguments (3 given) py> e = MyErr(sometup) py> print e Error with 1-2 James -- James Stroud UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: reading a list from a file
Rune Strand wrote:
> But iif it are many lists in the file and they're organised like this:
>
> ['a','b','c','d','e']
> ['a','b','c','d','e']
> ['A','B','C','D','E'] ['X','F','R','E','Q']
>
> I think this'll do it
>
> data = open('the_file', 'r').read().split(']')
>
> lists = []
> for el in data:
> el = el.replace('[', '').strip()
> el = el.replace("'", "")
> lists.append(el.split(','))
>
> # further processing of lists
>
> but the type problem is still to be resolved ;-)
>
Try this:
["O'Reilly, Fawlty, and Manuel", '""', ',', '"Hello", said O\'Reilly']
:-)
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Install MySQL-python-0.9.1
I am trying to install MySQL-Python 0.9.1 on my Solaris 8 system. The system has Python 2.3.3 and Mysql 4.0.21 installed. This is where I downloaded the distribution of the Mysql-python package: http://www.ravenbrook.com/project/p4dti/import/2001-10-16/MySQL-python-0.9.1/MySQL-python-0.9.1.tar.gz I have been doing whatever instructed from the README file. i.e. change the setup.py according to what OS I'm using: elif sys.platform == "sunos5": # Solaris 2.8 include_dirs = ['/usr/local/mysql/include/mysql'] library_dirs = ['/usr/local/mysql/lib/mysql'] libraries = [mysqlclient, "z"] runtime_library_dirs = ['/usr/local/lib:/usr/openwin/lib:/usr/dt/lib'] extra_objects = [] Then run the setup.py script with Python, here is the problem. I am encountering the following issue when running the setup.py script. Do u know why is that? Thanks! == python setup.py build Traceback (most recent call last): File "setup.py", line 123, in ? extra_objects=extra_objects, File "/usr/local/lib/python2.3/distutils/core.py", line 101, in setup _setup_distribution = dist = klass(attrs) File "/usr/local/lib/python2.3/distutils/dist.py", line 130, in __init__ setattr(self, method_name, getattr(self.metadata, method_name)) AttributeError: DistributionMetadata instance has no attribute 'get___doc__' python setup.py install Traceback (most recent call last): File "setup.py", line 123, in ? extra_objects=extra_objects, File "/usr/local/lib/python2.3/distutils/core.py", line 101, in setup _setup_distribution = dist = klass(attrs) File "/usr/local/lib/python2.3/distutils/dist.py", line 130, in __init__ setattr(self, method_name, getattr(self.metadata, method_name)) AttributeError: DistributionMetadata instance has no attribute 'get___doc__' -- http://mail.python.org/mailman/listinfo/python-list
Re: Question about HTMLgen
On 6/20/05, Sebastian Bassi <[EMAIL PROTECTED]> wrote:
> Hello,
>
> I am using HTMLgen. It is very nice. But I can't make it to
> generate an arbitrary command.
> For example I want to output this:
>
> type="image/svg+xml" name="wmap" wmode="transparent">
Works for me...
>>> d = HTMLgen.BasicDocument()
>>> d.append('')
>>> print d
- kv
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Re: Python and encodings drives me crazy
Oliver Andrich wrote:
> 2005/6/21, Konstantin Veretennicov <[EMAIL PROTECTED]>:
>
>>It does, as long as headline and caption *can* actually be encoded as
>>macroman. After you decode headline from utf-8 it will be unicode and
>>not all unicode characters can be mapped to macroman:
>>
>>
>u'\u0160'.encode('utf8')
>>
>>'\xc5\xa0'
>>
>u'\u0160'.encode('latin2')
>>
>>'\xa9'
>>
>u'\u0160'.encode('macroman')
>>
>>Traceback (most recent call last):
>> File "", line 1, in ?
>> File "D:\python\2.4\lib\encodings\mac_roman.py", line 18, in encode
>>return codecs.charmap_encode(input,errors,encoding_map)
>>UnicodeEncodeError: 'charmap' codec can't encode character u'\u0160' in
>>position
>> 0: character maps to
>
>
> Yes, this and the coersion problems Diez mentioned were the problems I
> faced. Now I have written a little cleanup method, that removes the
> bad characters from the input
By "bad characters", do you mean characters that are in Unicode but not
in MacRoman?
By "removes the bad characters", do you mean "deletes", or do you mean
"substitutes one or more MacRoman characters"?
If all you want to do is torch the bad guys, you don't have to write "a
little cleanup method".
To leave a tombstone for the bad guys:
>>> u'abc\u0160def'.encode('macroman', 'replace')
'abc?def'
>>>
To leave no memorial, only a cognitive gap:
>>> u'The Good Soldier \u0160vejk'.encode('macroman', 'ignore')
'The Good Soldier vejk'
Do you *really* need to encode it as MacRoman? Can't the Mac app
understand utf8?
You mentioned cp850 in an earlier post. What would you be feeding
cp850-encoded data that doesn't understand cp1252, and isn't in a museum?
Cheers,
John
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Re: What is different with Python ?
"Claudio Grondi" <[EMAIL PROTECTED]> writes: > > What has it all to do with Python? To be not fully off-topic, I > suggest here, that it is much easier to discuss programming > related matters (especially in case of Python :-) or mathematics > than any other subjects related to nature, because programming is > _so easy_ compared to what is going on in the "real world". > I see the reason for that in the fact, that programming is based > on ideas and rules developed by humans themselves, so it is > relatively easy to test and proove if statements are right or not. As a mathematician, I have to say "ugh". Not all statements are easy to test and prove. In fact, in any non-trivial mathematical system, there will be statements that *cannot* be proven to be either true or false. Some of those statements are interesting. The legends of mathematics are problems that aren't easy to test and prove: fermant's last theorem, the four color map theorem, and so on. Check out http://mathworld.wolfram.com/UnsolvedProblems.html > for a longer list. It's not clear that the ideas/rules were "developed" by humans. I'd say "discovered". In some cases in the past, mathematicians unhappy about some rule set out to show that it must be true (or false). In failing to show that, they invented a new branch of mathematics. I'd say programming is more like that. But I approach programming from a mathematicians viewpoint. http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: What is different with Python ?
Andrew Dalke <[EMAIL PROTECTED]> writes: > Andrea Griffini wrote: > > Wow... I always get surprises from physics. For example I > > thought that no one could drop confutability requirement > > for a theory in an experimental science... > > Some physicists (often mathematical physicists) propose > alternate worlds because the math is interesting. Mathematicians, on the other hand, tried to demonstrate that their alternate worlds couldn't exist - and found the math in their failures interesting. Hence we get non-euclidean geometries and other interesting things - that physicists find useful. (To be fair, some of the alternate mathematical world were first explored by physicists). http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: What is different with Python ?
Andrea Griffini <[EMAIL PROTECTED]> writes: > On Tue, 14 Jun 2005 16:40:42 -0500, Mike Meyer <[EMAIL PROTECTED]> wrote: > > >Um, you didn't do the translation right. > > Whoops. > > So you know assembler, no other possibility as it's such > a complex language that unless someone already knows it > (and in the specific architecture) what i wrote is pure > line noise. > > You studied it after python, I suppose. Nope. I don't think I've learned any assemblers since I learned Python. Of course, I'd been writing code for 20 years before I learned Python. > >> or, even more concrete and like what I learned first > >> > >> lda $300 > >> clc > >> adc $301 > >> sta $302 > >> > >> is simpler to understand. > > > >No, it isn't - because you have to worry about more details. > > In assembler details are simply more explicit. Unfortunately > with computers you just cannot avoid details, otherwise your > programs will suck bad. When I wrote in an high level language > or even a very high level one the details are understood even > if I'm not writing down them. After a while a programmer will > even be able to put them at a subconscius level and e.g. by > just looking at O(N^2) code that could be easily rewritten as > O(N) or O(1) a little bell will ring in you brain telling you > "this is ugly". But you cannot know if something is O(1) or > O(N) or O(N^2) unless you know some detail. If you don't like > details then programming is just not the correct field. I've never argued otherwise. > Think that "a = b + c" in computes the sum of two real > numbers and your program will fail (expecting, how fool, > that adding ten times 0.1 you get 1.0) and you'll spend > some time wondering why the plane crashed... your code > was "correct" after all. Especially if b and c aren't floats. I've always used "real" as a mathematical term, since they had it first. Computers don't deal with reals. > >For instance, whitesmith had a z80 assembler that let you write: > > > > a = b + c > > > >and it would generate the proper instructions via direct > >translation. > > To use that I've to understand what registers will be > affected and how ugly (i.e. inefficient) the code could > get. Programmin in assembler using such an high level > feature without knowing those little details woul be > just suicidal. The assembler lets you specify which registers to use. You either name them in place of variables, or variables that are labels for the registers. > >> But saying for example that > >> > >> del v[0] > >> > >> just "removes the first element from v" you will end up > >> with programs that do that in a stupid way, actually you > >> can easily get unusable programs, and programmers that > >> go around saying "python is slow" for that reason. > > > >That's an implementation detail. It's true in Python, but isn't > >necessarily true in other languages. > > Yeah. And you must know which is which. Otherwise you'll > write programs that just do not give the expected result > (because the user killed them earlier). Actually, it isn't always true in Python. What if v is a dictionary (in which case the description is wrong), or a class that maps an SQL table's row id's to objects holding the data for that row? In either case, the statement will be O(1). You do need to know which is which. > >Yes, good programmers need to know that information - or, > >as I said before, they need to know that they need to know > >that information, and where to get it. > > I think that a *decent* programmer must understand if the > code being written is roughly O(n) or O(n^2). Without > at least that the possibility of writing useful code, > excluding may be toy projects, is a flat zero. > Looking that information later may be just "too" late, > because the wrong data structure has already been used > and nothing can be done (except rewriting everything). I don't think those two statements contradict each other. A decent programmer will know the O() of the code they write - or where to find that information. And they'll check it beforehand. The advantage of using an HLL is that rewriting everything to try other data structures (after all, the constants that O() notation ignore matter as well, so that the fastest O() notation may not be the fastest solution for the problem in hand). > >That may well be true of the standard C++ library - I don't write > >it. But it certainly doesn't appear to be true of, for instance, > >Python internals. I've never seen someone explain why, for instance, > >string addition is O(n^2) beyond the very abstract "it creates a new > >string with each addition". No concrete details at all. > The problem is that unless you really internalized what > that means you'll forget about it. Don't ask me why, > but it happens. Our mind works that way. You just cannot > live with a jillion of unrelated details you cannot place > in a scheme. It doesn't work. One would do thousand times > the effort
Re: references/addrresses in imperative languages
On Sun, 19 Jun 2005 22:25:13 -0500, Terry Hancock <[EMAIL PROTECTED]> wrote: >> PS is there any difference between >> t=t+[li] >> t.append(li) > >No, but Yes, a big one. In the first you're creating a new list and binding the name t to it, in the second you're extending a list by adding one more element at the end. To see the difference: >>> a = [1,2,3] >>> b = a >>> a = a + [4] >>> print a [1, 2, 3, 4] >>> print b [1, 2, 3] >>> >>> a = [1,2,3] >>> b = a >>> a.append(4) >>> print a [1, 2, 3, 4] >>> print b [1, 2, 3, 4] >>> Andrea -- http://mail.python.org/mailman/listinfo/python-list
Re: Using print with format to stdout generates unwanted space
On 6/20/05, Michael Hoffman <[EMAIL PROTECTED]> wrote: > Paul Watson wrote: > > > While printf() does tightly control formatting in C, it does not in > > Python. > > There is no printf() in Python. You should not think of print as being a > Python version of printf. For quick and simple removal of the extra space, append a '\b' backspace character to your output "string" -- http://mail.python.org/mailman/listinfo/python-list
Re: reading a list from a file
But iif it are many lists in the file and they're organised like this:
['a','b','c','d','e']
['a','b','c','d','e']
['A','B','C','D','E'] ['X','F','R','E','Q']
I think this'll do it
data = open('the_file', 'r').read().split(']')
lists = []
for el in data:
el = el.replace('[', '').strip()
el = el.replace("'", "")
lists.append(el.split(','))
# further processing of lists
but the type problem is still to be resolved ;-)
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Re: references/addrresses in imperative languages
You can add Australia to the list :) Any volunteers for a fourth continent? Antarctica, perhaps? ;) - Jordan -- http://mail.python.org/mailman/listinfo/python-list
Re: reading a list from a file
If you decide to steer clear of eval, the following comes close to what
you want, and is somewhat Pythonic (I feel):
def back_to_list(str):
return str.strip("[]").split(", ")
>>> s = "[1, 2, 3, 4, 5, 6]"
>>> back_to_list(s)
['1', '2', '3', '4', '5', '6']
So parsing the list structure is pretty easy. The problem is the list
elements are still in string form.
If they're only integers like in this example, you're fine. If they're
arbitrary objects, on the other hand, well then you may need eval after
all.
Question is, how did they get printed to a file in this form in the
first place?
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Re: Python and encodings drives me crazy
2005/6/21, Konstantin Veretennicov <[EMAIL PROTECTED]>:
> It does, as long as headline and caption *can* actually be encoded as
> macroman. After you decode headline from utf-8 it will be unicode and
> not all unicode characters can be mapped to macroman:
>
> >>> u'\u0160'.encode('utf8')
> '\xc5\xa0'
> >>> u'\u0160'.encode('latin2')
> '\xa9'
> >>> u'\u0160'.encode('macroman')
> Traceback (most recent call last):
> File "", line 1, in ?
> File "D:\python\2.4\lib\encodings\mac_roman.py", line 18, in encode
> return codecs.charmap_encode(input,errors,encoding_map)
> UnicodeEncodeError: 'charmap' codec can't encode character u'\u0160' in
> position
> 0: character maps to
Yes, this and the coersion problems Diez mentioned were the problems I
faced. Now I have written a little cleanup method, that removes the
bad characters from the input and finally I guess I have macroman
encoded files. But we will see, as soon as I try to open them on the
Mac. But now I am more or less satisfied, as only 3 obvious files
aren't converted correctly and the other 1000 files are.
Thanks for your hints, tips and so on. Good Night.
Oliver
--
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Re: Python and encodings drives me crazy
On 6/20/05, Oliver Andrich <[EMAIL PROTECTED]> wrote:
> Does the following code write headline and caption in
> MacRoman encoding to the disk?
>
> f = codecs.open(outfilename, "w", "macroman")
> f.write(headline)
It does, as long as headline and caption *can* actually be encoded as
macroman. After you decode headline from utf-8 it will be unicode and
not all unicode characters can be mapped to macroman:
>>> u'\u0160'.encode('utf8')
'\xc5\xa0'
>>> u'\u0160'.encode('latin2')
'\xa9'
>>> u'\u0160'.encode('macroman')
Traceback (most recent call last):
File "", line 1, in ?
File "D:\python\2.4\lib\encodings\mac_roman.py", line 18, in encode
return codecs.charmap_encode(input,errors,encoding_map)
UnicodeEncodeError: 'charmap' codec can't encode character u'\u0160' in position
0: character maps to
- kv
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Re: reading a list from a file
Be careful, though - make sure you can absolutely trust your source of data before calling eval on it. If an unauthorised person could forseeably modify your file, then they could insert a string containing arbitrary Python code into it in place of your list, and then running your program would cause that code to be executed. So, to put it bluntly, eval is dangerous. Sure is convenient, though :) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and encodings drives me crazy
Oliver Andrich wrote:
> Well, I narrowed my problem down to writing a macroman or cp850 file
> using the codecs module. The rest was basically a misunderstanding
> about codecs module and the wrong assumption, that my input data is
> iso-latin-1 encode. It is UTF-8 encoded. So, curently I am at the
> point where I have my data ready for writing
>
> Does the following code write headline and caption in MacRoman
> encoding to the disk? Or better that, is this the way to do it?
> headline and caption are both unicode strings.
>
> f = codecs.open(outfilename, "w", "macroman")
> f.write(headline)
> f.write("\n\n")
> f.write(caption)
> f.close()
looks ok - but you should use u"\n\n" in general - if that line for some
reason chages to "öäü" (german umlauts), you'll get the error you
already observed. But using u"äöü" the parser pukes at you when the
specified coding of the file can't decode that bytes to the unicode object.
Most problems occdure when one confuses unicode objects with strings -
this requires a coercion that will be done using the default encoding
error you already observed.
Diez
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Re: Using print with format to stdout generates unwanted space
Paul Watson wrote: > While printf() does tightly control formatting in C, it does not in > Python. There is no printf() in Python. You should not think of print as being a Python version of printf. -- Michael Hoffman -- http://mail.python.org/mailman/listinfo/python-list
Re: references/addrresses in imperative languages
Jeremy Jones wrote: > I think the only reason I read your posts is for comedy, Indeed. > Xah Lee wrote: > ... [ lots of stuff, that if Xah cared about Xah would attempt to write > better docs, rather than criticise) ... ... >>Btw, behavior such as this one, common in imperative languages and info >>tech industry, is a criminality >> > Nice. If you don't like something, just call it "a criminality". Let > me try: the criminality of Xah Lee's postings caused all occupants of > at least 4 continents to roll their eyes. You know - even though I > think my assertion had some validity, I think even there it's ridiculous > to make such a forceful assertion without a foundation for it. Oh, I don't know, the level of swearing on Xah's posts might be criminal in some countries attached to Usenet - there's a lot of dodgy governments in the world. (Then again, Xah may just have "net-tourettes" (no offense to anyone intended) :-) However 4 continents rolling their eyes? I'm guessing that you're in the North American continent from your email, I'm in Europe, so that's at least 2 continents... >:-) Michael. -- http://mail.python.org/mailman/listinfo/python-list
Question about HTMLgen
Hello, I am using HTMLgen. It is very nice. But I can't make it to generate an arbitrary command. For example I want to output this: Each time I put "<" it gets escaped from HTML, instead of being inserted inside. -- http://www.spreadfirefox.com/?q=affiliates&id=24672&t=1";>La web sin popups ni spyware: Usa Firefox en lugar de Internet Explorer -- http://mail.python.org/mailman/listinfo/python-list
Re: reading a list from a file
- Original Message - From: "David Bear" <[EMAIL PROTECTED]> > I have a file that contains lists -- python lists. sadly, these are not > pickled. These are lists that were made using a simple print list > statement. > > Is there an easy way to read this file into a list again? I'm thinking I > would have to > > > I was hoping there was a pythonic way of doing this.. > a = '[1,2,3,4,5]' >>> b = eval(a) >>> b [1, 2, 3, 4, 5] >>> b[2] 3 HTH :) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and encodings drives me crazy
Well, I narrowed my problem down to writing a macroman or cp850 file
using the codecs module. The rest was basically a misunderstanding
about codecs module and the wrong assumption, that my input data is
iso-latin-1 encode. It is UTF-8 encoded. So, curently I am at the
point where I have my data ready for writing
Does the following code write headline and caption in MacRoman
encoding to the disk? Or better that, is this the way to do it?
headline and caption are both unicode strings.
f = codecs.open(outfilename, "w", "macroman")
f.write(headline)
f.write("\n\n")
f.write(caption)
f.close()
Best regards,
Oliver
--
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--
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reading a list from a file
I have a file that contains lists -- python lists. sadly, these are not pickled. These are lists that were made using a simple print list statement. Is there an easy way to read this file into a list again? I'm thinking I would have to read until char = '[' read until char = " ' " Well, reading character by char until I have the list and then parse it all myself. I was hoping there was a pythonic way of doing this.. -- David Bear -- let me buy your intellectual property, I want to own your thoughts -- -- http://mail.python.org/mailman/listinfo/python-list
Re: sudoku dictionary attack
Has some one an sodoku-task-generator? Here another solutions-ways: http://www.python-forum.de/viewtopic.php?t=3378 -- input -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and encodings drives me crazy
> I know this isn't your question, but why write: > > > data = apply(string.replace, [data, html, char]) > > when you could write > > data = data.replace(html, char) > > ?? Cause I guess, that I am already blind. Thanks. Oliver -- Oliver Andrich <[EMAIL PROTECTED]> --- http://fitheach.de/ -- http://mail.python.org/mailman/listinfo/python-list
Re: JEP and JPype in a single process
skn wrote:
> Hello,
>
> I have written a very simple java class file, which invokes a Python script
> using JEP.
>
> Code snippet:-
> ---
> Jep jep = new Jep(false);
> jep.runScript("C:\\temp\\testscript.py");
> jep.close();
>
> Now inside this Python script I want to make Java calls using JPype.
> If I use startjvm() inside this Python script, a Runtime Error (exception)
> is thrown.
> Also tried attachThreadToJVM(), but doesn't work, again Runtime Error.
>
> Any clues as to how I could achieve my goal??
> The interaction shown below should happen in a single process.
>
> JAVA ==> jep ==> PYTHON ==> jpype ==> JAVA
>
> Regards,
> skn
>
>
You're trying to do something I hope to make possible somewhere down the
road ...
As of today, I do not think it is possible. JPype does not provide a way
to initialize the JVM-bridge system except for startJvm .. which seems
to be prohibited when a JVM is already running.
AttachThreadToJVM will only work once the JVM-bridge system has been
initialize.
I will look into providing a sister method to startJVM to attach to the
currently running JVM instead of starting a new one. IF it does not
require major changes I will release it as 0.5.1. If you'd like you can
submit an enhancement request on the JPype sourceforge page, so this
doesn't get lost.
--
Steve Menard
Maintainer of http://jpype.sourceforge.net
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Re: Python and encodings drives me crazy
Oliver Andrich wrote: > def remove_html_entities(data): > for html, char in html2text: > data = apply(string.replace, [data, html, char]) > return data I know this isn't your question, but why write: > data = apply(string.replace, [data, html, char]) when you could write data = data.replace(html, char) ?? STeVe -- http://mail.python.org/mailman/listinfo/python-list
[no subject]
#! rnews 902 Newsgroups: comp.lang.python Path: news.xs4all.nl!newsspool.news.xs4all.nl!transit.news.xs4all.nl!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!nntp.abs.net!attws2!ip.att.net!NetNews1!xyzzy!nntp From: Harry George <[EMAIL PROTECTED]> Subject: Re: Couple functions I need, assuming they exist? X-Nntp-Posting-Host: cola2.ca.boeing.com Content-Type: text/plain; charset=us-ascii Message-ID: <[EMAIL PROTECTED]> User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 Lines: 15 Sender: [EMAIL PROTECTED] Organization: The Boeing Company References: <[EMAIL PROTECTED]> Mime-Version: 1.0 Date: Mon, 20 Jun 2005 20:12:51 GMT Xref: news.xs4all.nl comp.lang.python:382593 Charles Krug <[EMAIL PROTECTED]> writes: [snip] > The target of the problems (my daughter) ... [snip] That sounds familiar :-). See: http://www.seanet.com/~hgg9140/math/index.html http://www.seanet.com/~hgg9140/math/k6.html -- [EMAIL PROTECTED] 6-6M21 BCA CompArch Design Engineering Phone: (425) 294-4718 -- http://mail.python.org/mailman/listinfo/python-list
Python and encodings drives me crazy
Hi everybody, I have to write a little skript, that reads some nasty xml formated files. "Nasty xml formated" means, we have a xml like syntax, no dtd, use html entities without declaration and so on. A task as I like it. My task looks like that... 1. read the data from the file. 2. get rid of the html entities 3. parse the stuff to extract the content of two tags. 4. create a new string from the extracted content 5. write it to a cp850 or even better macroman encoded file Well, step 1 is easy and obvious. Step is solved for me by = code = from htmlentitydefs import entitydefs html2text = [] for k,v in entitydefs.items(): if v[0] != "&": html2text.append(["&"+k+";" , v]) else: html2text.append(["&"+k+";", ""]) def remove_html_entities(data): for html, char in html2text: data = apply(string.replace, [data, html, char]) return data = code = Step 3 + 4 also work fine so far. But step 5 drives me completely crazy, cause I get a lot of nice exception from the codecs module. Hopefully someone can help me with that. If my code for processing the file looks like that: def process_file(file_name): data = codecs.open(file_name, "r", "latin1").read() data = remove_html_entities(data) dom = parseString(data) print data I get Traceback (most recent call last): File "ag2blvd.py", line 46, in ? process_file(file_name) File "ag2blvd.py", line 33, in process_file data = remove_html_entities(data) File "ag2blvd.py", line 39, in remove_html_entities data = apply(string.replace, [data, html, char]) File "/usr/lib/python2.4/string.py", line 519, in replace return s.replace(old, new, maxsplit) UnicodeDecodeError: 'ascii' codec can't decode byte 0xe5 in position 0: ordinal not in range(128) I am pretty sure that I have iso-latin-1 files, but after running through my code everything looks pretty broken. If I remove the call to remove_html_entities I get Traceback (most recent call last): File "ag2blvd.py", line 46, in ? process_file(file_name) File "ag2blvd.py", line 35, in process_file print data UnicodeEncodeError: 'ascii' codec can't encode character u'\x96' in position 2482: ordinal not in range(128) And this continues, when I try to write to a file in macroman encoding. As I am pretty sure, that I am doing something completely wrong and I also haven't found a trace in the fantastic cookbook, I like to ask for help here. :) I am also pretty sure, that I do something wrong as writing a unicode string with german umlauts to a macroman file opened via the codecs module works fine. Hopefully someone can help me. :) Best regards, Oliver -- Oliver Andrich <[EMAIL PROTECTED]> --- http://fitheach.de/ -- http://mail.python.org/mailman/listinfo/python-list
Re: binary file
Kent Johnson wrote:
> Nader Emami wrote:
>> Kent Johnson wrote:
>>> Nader Emami wrote:
I have used the profile module to measure some thing as the next
command:
profile.run('command', 'file')
...How can I read (or convert) the binary file to an ascii file?
>>> Use an instance of pstats.Stats to interpret the results:
>>> from pstats import Stats
>>> s = Stats('file')
>>> s.print_stats()
>> I got the same result as the execution of command. But I would like to
>> write to the an external 'ascii' file!
> Oh, I get it, pstats.Stats doesn't have a way to send the output to a
> file. That's surprising!
I may be missing something here, but:
import sys, pstats
s = pstats.Stats('file')
sys.stdout, old = open('somefile.txt', 'w'), sys.stdout
s.print_stats()
sys.stdout, old = old, sys.stdout
old.close()
Looks to solve your problem to me.
--Scott David Daniels
[EMAIL PROTECTED]
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Re: Python choice of database
I am really surprised that someone hasn't mentioned Gadfly yet. It is a quick, free, relational database written directly for Python itself. http://gadfly.sourceforge.net/ Brian --- Philippe C. Martin wrote: > Hi, > > I am looking for a stand-alone (not client/server) database solution for > Python. > > 1) speed is not an issue > 2) I wish to store less than 5000 records > 3) each record should not be larger than 16K > > > As I start with Python objects, I thought of using shelve, but looking at > the restrictions (record size + potential collisions) I feel I should study > my options a bit further before I get started. > > > Regards, > > Philippe > -- http://mail.python.org/mailman/listinfo/python-list
Re: UML to Python/Java code generation
James wrote: > The brain may be fine for generating Python from UML but it is MANY > MANY orders of magnitude harder to generate UML from code with just > your brain than using a tool (usually zero effort and error free) no > matter how good you are at Python. I've really only used Rational Rose, but that tool is really limited in both directions. Class structure to class diagrams work both ways (not for Python, but for Java and C++ at least) but that's just a tiny part of UML. I don't expect any tool to do anything meaningful about e.g. use case diagrams, but what about activity diagrams, sequence diagrams, collaboration diagrams and state diagrams? I agree that the brain is poor at such things, but I doubt that any current tool is much better except for trivial subsets of UML. -- http://mail.python.org/mailman/listinfo/python-list
Re: Embedded Systems Python?
Dennis Clark wrote: > I'm a bit of a newb when it comes to Python, is there anyone with experience > compiling it on Linux platforms that can offer me pointers to try this out > myself? Seatch for cross-compiling python patches. I'm working on an XScale255 platform with python2.2 and soon 2.3 - no trouble there. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
Yes, I agree, but as most of the customer base I target uses the O/S that cannot be named ;-) , file names could become a problem just as 'ln -s' is out of the question. Yet, this might be the best trade-off. Regards, Philippe Oren Tirosh wrote: > Philippe C. Martin wrote: >> Hi, >> >> I am looking for a stand-alone (not client/server) database solution for >> Python. >> >> 1) speed is not an issue >> 2) I wish to store less than 5000 records >> 3) each record should not be larger than 16K > > How about using the filesystem as a database? For the number of records > you describe it may work surprisingly well. A bonus is that the > database is easy to manage manually. One tricky point is updating: you > probably want to create a temporary file and then use os.rename to > replace a record in one atomic operation. > > For very short keys and record (e.g. email addresses) you can use > symbolic links instead of files. The advantage is that you have a > single system call (readlink) to retrieve the contents of a link. No > need to open, read and close. > > This works only on posix systems, of course. The actual performance > depends on your filesystem but on linux and BSDs I find that > performance easily rivals that of berkeleydb and initialization time is > much faster. This "database" also supports reliable concurrent access > by multiple threads or processes. > > See http://www.tothink.com/python/linkdb > > Oren -- http://mail.python.org/mailman/listinfo/python-list
Re: references/addrresses in imperative languages
Walter Roberson wrote: > In article <[EMAIL PROTECTED]>, > Xah Lee <[EMAIL PROTECTED]> wrote: > >In hindsight analysis, such language behavior forces the programer to > >fuse mathematical or algorithmic ideas with implementation details. A > >easy way to see this, is to ask yourself: how come in mathematics > >there's no such thing as "addresses/pointers/references". > > There is. Each variable in predicate calculas is a reference. > No matter how large the formulae, a change in a variable > is, in mathematics, immediately propagated to all occurances > of the variable (potentially changing the references of other > variables). Variables don't change in mathematics, at least the run-of-the-mill everyday mathematics. :) > If the predicate calculas variables were not equivilent to references, > then the use of the variable in a formula would have to be a > non-propogating copy. and a change to the original value whence not > be reflected in all parts of the formula and would not change > what the other variables referenced. > > Consider for example the proof of Goedel's Incompleteness > theorem, which involves constructing a formula with a free > variable, and constructing the numeric encoding of that > formula, and then substituting the numeric encoding in as > the value of the free variable, thus ending up with > a number that is "talking about" iteelf. All these substitutions ``work'' in a way that is analogous to functional programming. For example, substituting a variable into a formula generates a new formula with occurences of that variable replaced by the given value. You haven't destroyed the old formula. > The process of > the proof is *definitely* one of "reference" to a value > in the earlier stages, with the formula being "evaluated" > at a later point -- very much like compiling a program > and then feeding the compiled program as input to itelf. Actually no. The process specifically avoids the pointer problem by using an arithmetic coding for the formula, the Goedel numbering. The formula talks about an encoded version of itself. That's how the self-reference is smuggled in, via the Goedel numbering. > You > cannot do it without a reference, because you need to > have the entire number available as data at the time > you start evaluating the mathematical formula. The final result just /is/ self-referential. It's not constructed bit by bit like a data structure inside a digital computer that starts out being non-self-referential and is then backpatched to point to itself. A mathematical derivation may give you the idea that something is changing in place, because you always hold the most recent version of the formula at the forefront of your mind, and can visualize the whole process as a kind of in-place animation in your head. But really, at each step you are making something completely new which stands on its own. -- http://mail.python.org/mailman/listinfo/python-list
Re: Embedded Systems Python?
Dennis Clark wrote: ... > Has anyone, or is anyone working with Python in an embedded Linux > environment? Mine is NO where near as constrained as a cell phone since > I've got plenty of memory to work with, I'm just running a Linux 2.4 > kernel on an ARM9 platform. This really shouldn't be a problem - especially given python can be made to run on mobile phones (Nokia Series 60). We've found using python on Series 60 phones to be quite useful, so if you're using a linux box, you're presumably got more memory/CPU available than there, so I doubt you'll see major problems. Regards, Michael. -- http://kamaelia.sourceforge.net/ -- http://mail.python.org/mailman/listinfo/python-list
Re: What is different with Python ?
Andrea Griffini wrote: > Indeed when talking about if learning "C" can hinder > or help learning "C++" I remember thinking that to > learn "C++" *superficially* learning "C" first is > surely pointless or can even hinder. > But to learn "C++" deeply (with all its quirks) I > think that learning "C" first helps. I think you are mistakingly bringing order into the picture, when extent is more likely the case. If you want to master C++, I think that most would agree you need to understand C. But there are many who would disagree that the path to C++ must *start* at C. (In fact, many people argue that a lot of bad C++ is due to people programming C in C++.) Instead they would argue that you should start by learning C++ "superficially", then learn C, and re-evaluate you C++ practices in light of the lessons learned from C. The example I'll pull out is natural languages - I understood the grammar & construction of my native tounge *much* better after learning a foreign language. From people I've talked to, this is a common occurance. But there would be few people who would advocate that one should learn a foreign language before learning one's native tounge. -- http://mail.python.org/mailman/listinfo/python-list
Re: Overcoming herpetophobia (or what's up w/ Python scopes)?
On 2005-06-18 05:26:13 +0100, Dennis Lee Bieber <[EMAIL PROTECTED]> said: > On Sat, 18 Jun 2005 03:02:13 +1000, Steven D'Aprano > <[EMAIL PROTECTED]> declaimed the following in > comp.lang.python: > >> >> The language is *always* spelt without the "a", and usually all in >> lower-case: perl. >> > Given that, at least one well known, book relates the name to > Practical Extraction (&) Report Language, whether that was a retrofit or > not -- I'd be tempted to user PERL for the name... All lowercase most > likely reflects the standard habits of Linux/Unix command naming. I'd heard it was pathologically eclectic rubbish lister, but then you can't believe everything you hear :-) John Ochiltree -- 667 - The Neighbour of the Beast -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
Philippe C. Martin wrote: > Hi, > > I am looking for a stand-alone (not client/server) database solution for > Python. > > 1) speed is not an issue > 2) I wish to store less than 5000 records > 3) each record should not be larger than 16K How about using the filesystem as a database? For the number of records you describe it may work surprisingly well. A bonus is that the database is easy to manage manually. One tricky point is updating: you probably want to create a temporary file and then use os.rename to replace a record in one atomic operation. For very short keys and record (e.g. email addresses) you can use symbolic links instead of files. The advantage is that you have a single system call (readlink) to retrieve the contents of a link. No need to open, read and close. This works only on posix systems, of course. The actual performance depends on your filesystem but on linux and BSDs I find that performance easily rivals that of berkeleydb and initialization time is much faster. This "database" also supports reliable concurrent access by multiple threads or processes. See http://www.tothink.com/python/linkdb Oren -- http://mail.python.org/mailman/listinfo/python-list
RE: Python choice of database
One db that is very much worth trying is Firebird. This is an open source Interbase 6.0 (Borland product) compatible db. It is a SourceForge project. There are three versions: the super server which is a client/server db, classic server (the one that I am very familiar with) which is also a client/server db, and the embedded server which is a standalone. In order to access the database you need the open source module KInterbasdb which is also a SourceForge project. KInterbasdb is a Python DB API 2.0 database driver. Firebird has a lot of documentation. Moreover it was made based on the Interbase 6.0, which is was made open source by Borland, so all of Borland's documentation and tools apply as well. Firebird can be found at: http://firebird.sourceforge.net/ KInterbasdb can be found at: http://kinterbasdb.sourceforge.net/ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Philippe C. Martin Sent: Monday, June 20, 2005 8:19 AM To: python-list@python.org Subject: Python choice of database Hi, I am looking for a stand-alone (not client/server) database solution for Python. 1) speed is not an issue 2) I wish to store less than 5000 records 3) each record should not be larger than 16K As I start with Python objects, I thought of using shelve, but looking at the restrictions (record size + potential collisions) I feel I should study my options a bit further before I get started. Regards, Philippe -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: login website that using PHP
Thank you all for the help. This problem bothered me for 3 days, Now I get it! You are right, it is the session cookie, after I use the cookiejar and the opener, I got it!!! I am really glad I found this place. Thank you again! -- http://mail.python.org/mailman/listinfo/python-list
Re: binary file
Nader Emami wrote:
> Kent Johnson wrote:
>
>> Nader Emami wrote:
>>
>>> L.S.,
>>>
>>> I have used the profile module to measure some thing as the next
>>> command:
>>>
>>> profile.run('command', 'file')
>>>
>>> But this make a binary file! How can I write the result of 'profile'
>>> in a ascii file? Others how can I read (or convert) the binary file
>>> to am ascii file?
>>
>>
>>
>> Use an instance of pstats.Stats to interpret the results:
>>
>> from pstats import Stats
>> s = Stats('file')
>> s.print_stats()
>>
>> etc.
>> http://docs.python.org/lib/profile-stats.html
>>
>> Kent
>
> I got the same result as the execution of command. But I would like to
> write to the an external 'ascii' file!
Oh, I get it, pstats.Stats doesn't have a way to send the output to a file.
That's surprising!
One option would be to write a program that outputs what you want, then
redirect the output in the shell. Alternatively take a look a the source for
print_stats() and write your own that outputs to a file.
Kent
--
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Re: Back to the future - python to C++ advice wanted
"Kay Schluehr" wrote:
> I recommend studying C++ idioms carefully.
>
> http://www1.bell-labs.com/user/cope/Patterns/C++Idioms/EuroPLoP98.html
Thanks for the link; very useful indeed.
> If Georges starts on greenfields he may have a look at Qt and it's
> object library which is not only concerned with widgets.
>
> http://doc.trolltech.com/3.3/
>
> BOOST is more high brow and I guess that it compiles slow because it
> uses templates extensively. Template metaprogramming as a compile time
> language was a funny discovery. Here is some prove of it's
> capabilities:
>
> http://osl.iu.edu/~tveldhui/papers/2003/turing.pdf
Many thanks to Kay and Bruno for suggesting Boost; I browsed through
its numerous libraries and they're quite impressive ! They seem
indispensable, especially for python (or other very high level
language) programmers going back to C++. Some libraries that seem to be
very relevant to pythoneers are:
- any: brings dynamic typing in C++
- tuple; 'nuff said
- iterator: out-of-the-box equivalents of
itertools.{imap,ifilter,izip,count}, reversed(), and others not
existing or applicable in python
- tokenizer, string_algo and regex: similar functionality to str.* and
re.*
- bind, mem_fn, function, functional, lambda: first class callables,
currying, higher order (functional) programming
- assign: syntactic sugar through operator overloading for (relatively)
readable container initialization:
map next = map_list_of(1,2)(2,3)(3,4)(4,5)(5,6);
is actually valid and equivalent to
next = dict([(1,2), (2,3), (3,4), (4,5), (5,6)])
- many, many more goodies, with or without respective standard python
equivalent (threads, graphs, math utils, serialization,
metaprogramming, etc).
- and last but not least, Boost.Python. I don't think it's just a
coincidence that among all languages they chose Python to make
interoperable with C++ :-)
Thanks again,
George
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Re: utf8 and ftplib
Richard Lewis wrote: > On Mon, 20 Jun 2005 14:27:17 +0200, "Fredrik Lundh" > <[EMAIL PROTECTED]> said: > > > > well, you're messing it up all by yourself. getting rid of all the > > codecs and > > unicode2charrefs nonsense will fix this: > > > Thanks for being so patient and understanding. > > OK, I've taken it all out. The only thinking about encoding I had to do > in the actual code I'm working on was to use: > file.write(document.toxml(encoding="utf-8")) > > instead of just > file.write(document.toxml()) > > because otherwise I got errors on copyright symbol characters. sounds like a bug in minidom... > My code now works without generating any errors but Konqueror's KHTML > and Embedded Advanced Text Viewer and IE5 on the Mac still show > capital-A-with-a-tilde in all the files that have been > generated/altered. Whereas my text editor and Mozilla show them > correctly. > > The "unicode2charrefs() nonsense" was an attempt to make it output with > character references rather than literal characters for all characters > with codes greater than 128. Is there a way of doing this? character references refer to code points in the Unicode code space, so you just convert the bytes you get after converting to UTF-8. however, if you're only using characters from the ISO Latin 1 set (which is a strict subset of Unicode), you could en- code to "iso-8859-1" and run unicode2charrefs on the result. but someone should really fix minidom so it does the right thing. (fwiw, if you use my ElementTree kit, you can simply do tree.write(encoding="us-ascii") and the toolkit will then use charrefs for any character that's not plain ascii. you can get ElementTree from here: http://effbot.org/zone/element-index.htm ) -- http://mail.python.org/mailman/listinfo/python-list
Re: utf8 and ftplib
Richard Lewis wrote: > My code now works without generating any errors but Konqueror's KHTML > and Embedded Advanced Text Viewer and IE5 on the Mac still show > capital-A-with-a-tilde in all the files that have been > generated/altered. Whereas my text editor and Mozilla show them > correctly. How are you viewing the files? You have to tell the browser that they are UTF-8. If you just double-click the file, the browser will use its default encoding. If you are server the files from a web server then you should set the Content-Type header correctly. Or you can tell the browser directly (try View / Encoding in IE). Kent -- http://mail.python.org/mailman/listinfo/python-list
Re: Embedded Systems Python?
I developed for my former employee a thin client whose primary purpose was AS400 connectivity. This required a fairly complex interactive gui configuration which I wrote in Python. This system could also be configed by a remote manager. Wrote that also in python using UDP sockets. The hardware was 64Mb memory and 64Mb compact flash. OS wa 2.4.20 linux from Debian I did a lot of cleanup removing unneeded modules but other than that, standard Python 2.3.4 worked great. Dennis Clark wrote: > Hi all, > > I've looked through the threads about embedded Python that are a year > and a half old, and I thought that I'd ask this question now to see if > anything has changed. > > Has anyone, or is anyone working with Python in an embedded Linux > environment? Mine is NO where near as constrained as a cell phone since > I've got plenty of memory to work with, I'm just running a Linux 2.4 kernel > on an ARM9 platform. > > Are there success stories for Python on embedded Linux systems today? > The embedded Java JVM's seem to all be propriatary and have quite high > license fees (don't mention Kaffe, it seems pretty fragile to me.) > > I'm a bit of a newb when it comes to Python, is there anyone with experience > compiling it on Linux platforms that can offer me pointers to try this out > myself? > > thanks, > DLC > -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
Correct, that's not a constraint right now. Paul Rubin wrote: > "Philippe C. Martin" <[EMAIL PROTECTED]> writes: >> 1) speed is not an issue >> 2) I wish to store less than 5000 records >> 3) each record should not be larger than 16K > > You don't mention whether multiple running programs need to use it > concurrently. That's usually done with client/server db's but it can > be done standalone. -- http://mail.python.org/mailman/listinfo/python-list
Re: Couple functions I need, assuming they exist?
On 20 Jun 2005 15:51:07 GMT, Duncan Booth <[EMAIL PROTECTED]> wrote:
> Peter Hansen wrote:
>
>>> The target of the problems (my daughter) would prefer that the thousands
>>> be delimited. Is there a string function that does this?
>>
>> You refer to something like putting a comma between groups of three
>> digits, as in 1,000? This is locale-specific, and there's a "locale"
>> module that should have what you need.
>
import locale
locale.setlocale(locale.LC_ALL, '')
> 'English_United Kingdom.1252'
print locale.format("%d", 100, True)
> 1,000,000
Perfect!
Thanks.
Sometimes "hard part" is figuring out which package already does the
thing I need done.
Charles.
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Re: login website that using PHP
"frost" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Hi, > > I am trying to login a website that using PHP and javascript. This is > what happend if you browse that website using IE, after you login, you > can go anywhere without enter your name and password again, as long as > you keep that IE open, but after you close that IE, then later on open > that website in a new window, you need to login again. I guess some > session is created as long as your original login window dose not > close. > > How I can handle this in python? I want get some information from that > website. But the login page is not what I want, how can I simulate > regular IE browser? I mean after I login, I can get to other pages from > it, but I find my programe can't go other place except the login page. > > Hope you could understand my question. Thank you very much! > Check here for some other examples, specifically 'Submitting values and clicking buttons in IE' http://tinyurl.com/7n7xf -- http://mail.python.org/mailman/listinfo/python-list
Re: login website that using PHP
On Sun, 19 Jun 2005 19:11:38 -0700, frost wrote: > Hi, > > I am trying to login a website that using PHP and javascript. This is > what happend if you browse that website using IE, after you login, you Browser remembers so called HTTP authorization header field. It sends authorization information whenever server requiress authorization by sending corresponding status code and, so called, realm specification. It is beyond the scope of this group and it is well described in HTTP standard and corresponding RFC. DG -- http://mail.python.org/mailman/listinfo/python-list
Re: sudoku dictionary attack
[EMAIL PROTECTED] wrote: > Thought I'd offer a method for solving all possible 9x9 sudoku puzzles > in one go. It'll takes a bit of time to run however (and 9x9 seems to > be about as big as is reasonably possible before combinatorial > explosion completely scuppers this type of program)... > > Basic idea:- > > Start with a grid initialised with: > > 123456789 > 234567891 > 345678912 > 456789123 > 567891234 > 678912345 > 789123456 > 891234567 > 912345678 > > Note that all rows and columns contain all 9 digits (but that the > sub-tiles aren't correct for a sudoku solution). > > Next write a program which permutes all 9 columns, and then for each of > those permutations permutes the last 8 rows. This will, I believe, > generate all possible grids with no digit repetitions in any row or > column. It will generate 14,631,321,600 (9!*8!) possible sudoku > candidates. Finally, check each candidate to see if any 3x3 subtile has > a repeated digit in it and discard as soon as a repeat is found (sooner > the better). Any that come through unscathed get written as a 82 (81 + > lf) char string to an output file. I'm having trouble coming up with anything that fits this grid: ..12. ..2x. . . . . . . . where x is not 3, by permuting columns, then rows. You may also have to permute the numbers. Although, even then, x=1 is still impossible. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
"Philippe C. Martin" <[EMAIL PROTECTED]> writes: > 1) speed is not an issue > 2) I wish to store less than 5000 records > 3) each record should not be larger than 16K You don't mention whether multiple running programs need to use it concurrently. That's usually done with client/server db's but it can be done standalone. -- http://mail.python.org/mailman/listinfo/python-list
Re: Couple functions I need, assuming they exist?
"Charles Krug" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > > The target of the problems (my daughter) would prefer that the thousands > be delimited. Is there a string function that does this? Be sure to use the locale approach and avoid rolling your own. -- http://mail.python.org/mailman/listinfo/python-list
Re: Want to learn a language - is Python right?
"Aziz McTang" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Hi Paul, > > Thanks for your input. > > As usual, hearing some answers helps formulate the question... > > What I'm looking for is more to learn one good, comprehensive > programming language well than several approximately on an ad hoc > basis. What I also failed to mention is the desire to develop my > presently limited computer skills a lot further. You have received some good advice. There are strong tools to support localization, but they are not inexpensive. They might be lower cost than developing your own. However, your goal to develop your programming skills is also a cost to be considered. Are you interested in developing an open source localization tool? A consideration for web applications is who will be maintaining the code. If these are all your own and no one else will ever work on them, then use any tool you like. Coding them in x86 assembly language would increase your computer knowledge, but we both know that is not the right tool for this task. -- http://mail.python.org/mailman/listinfo/python-list
sudoku dictionary attack
Thought I'd offer a method for solving all possible 9x9 sudoku puzzles
in one go. It'll takes a bit of time to run however (and 9x9 seems to
be about as big as is reasonably possible before combinatorial
explosion completely scuppers this type of program)...
Basic idea:-
Start with a grid initialised with:
123456789
234567891
345678912
456789123
567891234
678912345
789123456
891234567
912345678
Note that all rows and columns contain all 9 digits (but that the
sub-tiles aren't correct for a sudoku solution).
Next write a program which permutes all 9 columns, and then for each of
those permutations permutes the last 8 rows. This will, I believe,
generate all possible grids with no digit repetitions in any row or
column. It will generate 14,631,321,600 (9!*8!) possible sudoku
candidates. Finally, check each candidate to see if any 3x3 subtile has
a repeated digit in it and discard as soon as a repeat is found (sooner
the better). Any that come through unscathed get written as a 82 (81 +
lf) char string to an output file.
I've written a short program (in Python; see below) that tries out this
idea. Indications are that my HP nc6000 laptop can check around 30,000
candidates/sec and that c.0.15% of them are valid sudoku solutions.
That means it would take around 6.5 days to generate the between 20-30
million possible sudoku solutions it will find. That would require
around 2GB in uncompressed disk storage. Gzip does a VERY good job of
compressing files containing this type of data -- so I'd expect well
over 80% compression (might even fit on a CD then).
Once you've generated the solution data then comes the fun of searching
it efficiently which I leave as an exercise for the reader :-)
Regards, sub1ime_uk (at) yahoo (dot) com
==
#!python
#
# sudoku.py - generate all valid sudoku solutions
#
# Usage: sudoku
#eg: sudoku 9 3
# Whare:-
#N is the grid size (ie 9 for 9x9)
#S is the sub-tile size (3 for 3x3)
#
# (c) 2005 sub1ime_uk (at) yahoo (dot) com
#
import sys
from gzip import GzipFile
from time import time
def permute(s):
if len(s)==0: return
if len(s)==1:
yield s
return
for i in range(len(s)):
for t in permute(s[:i]+s[i+1:]):
yield s[i:i+1]+t
return
def populate(sz, ini):
tile = []
for i in range(sz):
tile.append([])
for j in range(sz):
x = chr((i+j)%sz+ord(ini))
tile[i].append(x)
return tile
def subtilesok(t, c, r, n, s):
for x in range(0, n, s):
for y in range(0, n, s):
d = {}
for i in range(s):
cn = c[x+i]
for j in range(s):
rn = r[y+j]
d[t[cn][rn]] = 1
if len(d.keys())!=n: return 0
return 1
def displaytile(t, c, r, lf):
lfstr=''
print
for i in r:
row = []
for j in c:
row.append(t[j][i])
r=''.join(row)
lfstr += r
print "",r
print
lf.write(lfstr+"\n")
def fact(n):
if n<2: return 1
return n*fact(n-1)
if __name__ == '__main__':
st = time()
logf = GzipFile("c:\\temp\\sudoku.gz", "w")
N=int(sys.argv[1])
S=int(sys.argv[2])
estimate = fact(N)*fact(N-1)
if N!=S*S:
print "Subtile size", S, "not sqrt of tile size", N
sys.exit(1)
cols = [x for x in range(N)]
rows = [x for x in range(1, N)]
primarytile = populate(N, '1')
count = 0
answc = 0
for colp in permute(cols):
for rowp in permute(rows):
count += 1
if subtilesok(primarytile, colp, [0]+rowp, N, S):
answc += 1
ct = time()
et=ct-st
if et>0.0:
print "Found: %d out of %d (%.2f%%) checked" % (answc, count,
(answc*100./count))
print "Progress: %.2f%%" % ((count*100./estimate))
print "Elapsed time: %.2f secs, checked: %d/s, found %d/s." %
(et, (count/et), (answc/et))
print "Estimate time to go: %.2f hours" %
((estimate-count)*et/(count*3600.))
else:
print "%d / %d (%5.2f%%)" % (answc, count,
(answc*100./count))
displaytile(primarytile, colp, [0]+rowp, logf)
print
print "Checked", count,"tiles. Found", answc,"answers."
logf.close()
sys.exit()
===
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Re: Python choice of database
Thanks, I'm looking at KirbyBase also but wonder if it can handle bitmaps (I could always pickle it first I guess). Regards, Philippe John Abel wrote: > Philippe C. Martin wrote: > >>Thank you all for your answers. >> >>A pure Python would have beenmy first choice. yet I now feel I should >>spend some time looking at PySQLite (I like the fact it's pre-compiled for >>Windows). >> >>Thanks. >> >>Philippe >> >> >> >>Philippe C. Martin wrote: >> >> >> >>>Hi, >>> >>>I am looking for a stand-alone (not client/server) database solution for >>>Python. >>> >>>1) speed is not an issue >>>2) I wish to store less than 5000 records >>>3) each record should not be larger than 16K >>> >>> >>>As I start with Python objects, I thought of using shelve, but looking at >>>the restrictions (record size + potential collisions) I feel I should >>>study my options a bit further before I get started. >>> >>> >>>Regards, >>> >>>Philippe >>> >>> >> >> >> > Out of the suggestions SnakeSQL and KirbyBase are pure python. Gadfly > is sorta pure, in that it will work without the compiled kjbuckets lib. > > J -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
> 1. 5000 files -- my personal favourite. You got a point William Park wrote: > Philippe C. Martin <[EMAIL PROTECTED]> wrote: >> Hi, >> >> I am looking for a stand-alone (not client/server) database solution >> for Python. >> >> 1) speed is not an issue >> 2) I wish to store less than 5000 records >> 3) each record should not be larger than 16K >> >> As I start with Python objects, I thought of using shelve, but looking >> at the restrictions (record size + potential collisions) I feel I >> should study my options a bit further before I get started. > > Possible approach might be: > 1. 5000 files -- my personal favourite. > 2. GDBM > 3. SQLite > -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
Philippe C. Martin <[EMAIL PROTECTED]> wrote: > Hi, > > I am looking for a stand-alone (not client/server) database solution > for Python. > > 1) speed is not an issue > 2) I wish to store less than 5000 records > 3) each record should not be larger than 16K > > As I start with Python objects, I thought of using shelve, but looking > at the restrictions (record size + potential collisions) I feel I > should study my options a bit further before I get started. Possible approach might be: 1. 5000 files -- my personal favourite. 2. GDBM 3. SQLite -- William Park <[EMAIL PROTECTED]>, Toronto, Canada ThinFlash: Linux thin-client on USB key (flash) drive http://home.eol.ca/~parkw/thinflash.html BashDiff: Full featured Bash shell http://freshmeat.net/projects/bashdiff/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
OK, I'll try that too. Regards, Philippe Erik Max Francis wrote: > Philippe C. Martin wrote: > >> You mean pickling a dictionnary of 5000/16K objects ? > > Yes. You said speed was not an issue; pickling only 5000 objects, each > no more than 16 kB, is easily handled by any remotely modern machine > (and even plenty which are not very modern). > -- http://mail.python.org/mailman/listinfo/python-list
Re: Couple functions I need, assuming they exist?
> I assume you mean translating something like '100' to '1,000,000'?
> I don't know of an existing function that does this, but here's a
> relatively simple implementation:
>
> py> import itertools as it
> py> def add_commas(s):
> ... rev_chars = it.chain(s[::-1], it.repeat('', 2))
> ... return ','.join(''.join(three_digits)
> ... for three_digits
> ... in it.izip(*[rev_chars]*3))[::-1]
> ...
Or for an equivalent less cryptic (IMHO) recipe:
def num2str(num):
'''Return a string representation of a number with the thousands
being delimited.
>>> num2str(65837)
'65,837'
>>> num2str(6582942)
'6,582,942'
>>> num2str(23)
'23'
>>> num2str(-1934)
'-1,934'
'''
parts = []
div = abs(num)
while True:
div,mod = divmod(div,1000)
parts.append(mod)
if not div:
if num < 0: parts[-1] *= -1
return ','.join(str(part) for part in reversed(parts))
Regards,
George
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Re: Python choice of database
Philippe C. Martin wrote: >Thank you all for your answers. > >A pure Python would have beenmy first choice. yet I now feel I should spend >some time looking at PySQLite (I like the fact it's pre-compiled for >Windows). > >Thanks. > >Philippe > > > >Philippe C. Martin wrote: > > > >>Hi, >> >>I am looking for a stand-alone (not client/server) database solution for >>Python. >> >>1) speed is not an issue >>2) I wish to store less than 5000 records >>3) each record should not be larger than 16K >> >> >>As I start with Python objects, I thought of using shelve, but looking at >>the restrictions (record size + potential collisions) I feel I should >>study my options a bit further before I get started. >> >> >>Regards, >> >>Philippe >> >> > > > Out of the suggestions SnakeSQL and KirbyBase are pure python. Gadfly is sorta pure, in that it will work without the compiled kjbuckets lib. J -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
Philippe C. Martin wrote: > You mean pickling a dictionnary of 5000/16K objects ? Yes. You said speed was not an issue; pickling only 5000 objects, each no more than 16 kB, is easily handled by any remotely modern machine (and even plenty which are not very modern). -- Erik Max Francis && [EMAIL PROTECTED] && http://www.alcyone.com/max/ San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis I used to walk around / Like nothing could happen to me -- TLC -- http://mail.python.org/mailman/listinfo/python-list
Re: import via pathname
[EMAIL PROTECTED] wrote: > AhhI see. I played around with the sys.path function...and it > looks like python automatically looks in the same directory as my > script first. Then is searches to all the other pre-defined paths. So > it works for me to just keep my main script in the same directory as > the two modules I'm using. Yup, as long as you're not worried about having too many modules around, that should work fine. =) STeVe -- http://mail.python.org/mailman/listinfo/python-list
Re: Want to learn a language - is Python right?
Aziz McTang wrote: > Hi Paul, > > Thanks for your input. > > As usual, hearing some answers helps formulate the question... > > What I'm looking for is more to learn one good, comprehensive > programming language well than several approximately on an ad hoc > basis. What I also failed to mention is the desire to develop my > presently limited computer skills a lot further. > > So although your answer to 1 suggests I'd be using a steam-roller to > kill a fly, if I do need to go further (or ask other people to help and > still understand what's going on: one site I may want to develop later > involves a number of languages including Japanese as well as audio) I > won't have to re-learn another program. Is this right? > > As to 2, I have yet to find a canned program that does what I want, and > so far every programmer I've asked to write it has said "hey that's > easy" then escaped, never to be heard of again. > > And 3: good! Actually, having learned half a dozen languages, I can > vouch for it being an excellent way to acquire and consolidate > vocabulary. Talking to (or, rather, understanding) the natives is > another kettle of fish! > > Thanks again! > > Any new slants from yourself or others are welcome. > > Aziz You can use CherryPy for creating a Python-esque web application. Never buy into the fluff that says Python is not as good as PHP for web apps! PHP is still too Perl-Like (meaning old and useless)! Python is the choice of a new generation baby!!! :) JK... For your vocab program, Python is actually perfect. This could even go for apps that require some Unicode and other Internationalization snafus (like right-to-left characters and Cyrillic typesets). If you're looking for one programming language then you should consider the idea that no one language can do it all (although Python comes close in my biased opinion). Python is not for memory management, writing device drivers and the like. As far as needing something for web apps, CherryPy is great -- just learn Python first. PHP is good but it has fallen out of favor with me though there are a ton of people out there who think it is the greatest thing since sliced bread. Take a look at the Python tutorial: http://docs.python.org/tut/tut.html. Good luck, Harlin Seritt -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
You mean pickling a dictionnary of 5000/16K objects ? Erik Max Francis wrote: > Philippe C. Martin wrote: > >> Well that would be shelve I guess ... with the restrictions I mentioned. > > I was talking about pickle, not shelve. > -- http://mail.python.org/mailman/listinfo/python-list
Re: Couple functions I need, assuming they exist?
Peter Hansen wrote:
>> The target of the problems (my daughter) would prefer that the thousands
>> be delimited. Is there a string function that does this?
>
> You refer to something like putting a comma between groups of three
> digits, as in 1,000? This is locale-specific, and there's a "locale"
> module that should have what you need.
>>> import locale
>>> locale.setlocale(locale.LC_ALL, '')
'English_United Kingdom.1252'
>>> print locale.format("%d", 100, True)
1,000,000
>>> print locale.format("%.2f", 100, True)
1,000,000.00
>>> locale.setlocale(locale.LC_ALL, 'fr')
'French_France.1252'
>>> print locale.format("%d", 100, True)
1 000 000
>>> print locale.format("%.2f", 100, True)
1 000 000,00
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Re: Python choice of database
Thank you all for your answers. A pure Python would have beenmy first choice. yet I now feel I should spend some time looking at PySQLite (I like the fact it's pre-compiled for Windows). Thanks. Philippe Philippe C. Martin wrote: > Hi, > > I am looking for a stand-alone (not client/server) database solution for > Python. > > 1) speed is not an issue > 2) I wish to store less than 5000 records > 3) each record should not be larger than 16K > > > As I start with Python objects, I thought of using shelve, but looking at > the restrictions (record size + potential collisions) I feel I should > study my options a bit further before I get started. > > > Regards, > > Philippe -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
Philippe C. Martin wrote: > Well that would be shelve I guess ... with the restrictions I mentioned. I was talking about pickle, not shelve. -- Erik Max Francis && [EMAIL PROTECTED] && http://www.alcyone.com/max/ San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis I used to walk around / Like nothing could happen to me -- TLC -- http://mail.python.org/mailman/listinfo/python-list
Re: Python choice of database
Well that would be shelve I guess ... with the restrictions I mentioned. Regards, Philippe Erik Max Francis wrote: > Philippe C. Martin wrote: > >> I am looking for a stand-alone (not client/server) database solution for >> Python. >> >> 1) speed is not an issue >> 2) I wish to store less than 5000 records >> 3) each record should not be larger than 16K >> >> >> As I start with Python objects, I thought of using shelve, but looking at >> the restrictions (record size + potential collisions) I feel I should >> study my options a bit further before I get started. > > Why not just use native Python data structures and pickle them? > -- http://mail.python.org/mailman/listinfo/python-list
Re: Couple functions I need, assuming they exist?
Charles Krug wrote:
> myWords = split(aString, aChar)
>
> is depreciated but
>
> myWords = aString.split(aChgar)
>
> is not?
Yes, that's basically correct. What's deprecated are the functions in
the string module. So
string.split(a_str, b_str)
is deprecated in favor of
a_str.split(b_str)
> The target of the problems (my daughter) would prefer that the thousands
> be delimited. Is there a string function that does this?
I assume you mean translating something like '100' to '1,000,000'?
I don't know of an existing function that does this, but here's a
relatively simple implementation:
py> import itertools as it
py> def add_commas(s):
... rev_chars = it.chain(s[::-1], it.repeat('', 2))
... return ','.join(''.join(three_digits)
... for three_digits
... in it.izip(*[rev_chars]*3))[::-1]
...
py> add_commas('10')
'10'
py> add_commas('100')
'100'
py> add_commas('1000')
'1,000'
py> add_commas('10')
'1,000,000,000'
In case you haven't seen it before, it.izip(*[itr]*N)) iterates over the
'itr' iterator in chunks of size N, discarding the last chunk if it is
less than size N. To avoid losing any digits, I initially pad the
sequence with two empty strings, guaranteeing that only empty strings
are discarded.
So basically, the function iterates over the string in reverse order, 3
characters at a time, and joins these chunks together with commas.
HTH,
STeVe
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Re: Python choice of database
John Abel wrote: > Gadfly > PySQLite ( requires SQLite library ) I want to clarify this parenthetical comment, for the record. When I first downloaded PySQLite I had already gone and installed SQLite, thinking it was a prerequisite in that sense. In fact, the PySQLite install includes a .pyd which contains a statically linked version of the complete SQLite library. No additional installation is required, making it an even simpler solution than I thought at first. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Using print with format to stdout generates unwanted space
Thanks for all replies.
Ok. I agree. While printf() does tightly control formatting in C, it does
not in Python. Using write() can be used to output with no changes to the
data.
"Tim Hoffman" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Hi Paul
>
> Based on your description of what you want to do, print is probably not
> the correct method of controlling output format. You should use write()
> method of the file handle to get unadulterated output.
>
> print is working as documented . From the Python 2.3 documentation,
> Section 6.6 The Print statement.
>
> "print evaluates each expression in turn and writes the resulting object
> to standard output (see below). If an object is not a string, it is first
> converted to a string using the rules for string conversions. The
> (resulting or original) string is then written. A space is written before
> each object is (converted and) written, unless the output system believes
> it is positioned at the beginning of a line. This is the case (1) when no
> characters have yet been written to standard output, (2) when the last
> character written to standard output is "\n", or (3) when the last write
> operation on standard output was not a print statement."
>
> As you can see a space char is written and is correct as per the docs.
>
> Rgds
>
> Tim
>
> Paul Watson wrote:
>> #!/usr/bin/env python
>>
>> # Using a print statement to stdout results in an
>> # unwanted space character being generated at the
>> # end of each print output. Same results on
>> # DOS/Windows and AIX.
>> #
>> # I need precise control over the bytes that are
>> # produced. Why is print doing this?
>> #
>> import sys
>>
>> # If this is a DOS/Windows platform, then put stdout
>> # into binary mode so that only the UNIX compatible newline
>> # will be generated.
>> #
>> try:
>> import msvcrt, os
>> msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
>> except:
>> print 'This is not an msvcrt platform.'
>> pass
>>
>> # Using print with newline suppressed generates a space at the
>> # end of each print statement.
>> #
>> for i in range(3):
>> print '%d,60,' % (i),
>> for j in range(10):
>> print '%d,' % (j),
>> print ''
>>
>> # Using a list and doing a join does not result in the space
>> # character being generated.
>> #
>> for i in range(3):
>> alist = []
>> alist.append('%d,60,' % (i))
>> for j in range(10):
>> alist.append('%d,' % (j))
>> print ''.join(alist)
>>
>> sys.exit(0)
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Re: JEP and JPype in a single process
On 6/20/05, skn <[EMAIL PROTECTED]> wrote:
> Hello,
>
> I have written a very simple java class file, which invokes a Python script
> using JEP.
. . .
> Now inside this Python script I want to make Java calls using JPype.
I am not familiar with either Jepp or JPype, but I spotted this
snippet on Jepp page (http://jepp.sourceforge.net/):
import jep
FileInputStream = jep.findClass('java.io.FileInputStream')
try:
fin = FileInputStream('adsf')
except jep.FileNotFoundException:
print 'Invalid file'
Are you sure you need to call JPype?
- kv
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Re: Python choice of database
Philippe C. Martin wrote: > I am looking for a stand-alone (not client/server) database solution for > Python. > > 1) speed is not an issue > 2) I wish to store less than 5000 records > 3) each record should not be larger than 16K > > As I start with Python objects, I thought of using shelve, but looking at > the restrictions (record size + potential collisions) I feel I should study > my options a bit further before I get started. You don't say whether you want *pure* Python solutions, so I'll suggest pysqlite which wraps the SQLite embedded database in a pretty much totally transparent fashion and is highly effective, fast, compact, reliable (so far, in my experience), and clean. You also don't say whether you want a SQL database, so if you are free to try anything, you might look at ZODB or Durus (think of it as a lighter-weight ZODB). I believe Durus is pure Python, but it might have some C code for performance (like ZODB). It's not SQL, and should perhaps be thought of (as it describes itself) as an object persistence solution, rather than a "database". -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: import via pathname
AhhI see. I played around with the sys.path function...and it looks like python automatically looks in the same directory as my script first. Then is searches to all the other pre-defined paths. So it works for me to just keep my main script in the same directory as the two modules I'm using. Thx! -- http://mail.python.org/mailman/listinfo/python-list
