[Tutor] problem with simple sqlite script
Hello, I am getting frustrated. I have been successfully inserting, deleting, etc records with python and sqlite no problem. Suddenly the following very simple scrip does not work: import sqlite3 sPath=r'e:\pythonexamples\aivars2.db' con=sqlite3.connect(sPath) cur=con.cursor() cur.execute(insert into test (name) values (?),sPath) con.commit() here is an error message Traceback (most recent call last): File C:\Python25\Lib\site-packages\pythonwin\pywin\framework\scriptutils.py, line 307, in RunScript debugger.run(codeObject, __main__.__dict__, start_stepping=0) File C:\Python25\Lib\site-packages\pythonwin\pywin\debugger\__init__.py, line 60, in run _GetCurrentDebugger().run(cmd, globals,locals, start_stepping) File C:\Python25\Lib\site-packages\pythonwin\pywin\debugger\debugger.py, line 631, in run exec cmd in globals, locals File E:\PythonExamples\test.py, line 7, in module cur.execute(insert into test (name) values (?),sPath) ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 28 supplied. What the hell is going on? I have used the syntax with (?) successfully before! I tested and found out that above script allows me to insert only single character into database. Then it works. Using ActiveState python 2.5, WinXP Thanks for any hint. Aivars ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
[EMAIL PROTECTED] wrote on more intermediate/advanced topics like linked lists, nodes, trees, etc. However, it's kind of like reading a math textbook Thats because these are abstract theoretical concepts at the root of programming but not used much in practice in high level languages like Python. If you were using a language like C or Fortran or Pascal they would be highly relevant because the language would not provide much support for collections of data. But Python offers such a wealth of data collections that these advanced topics are largely redundant; just use a list or a dictionary or a set... any suggestions for learning about real world application of more advanced concepts? There are general rules about when different types apply but the edges are blurred in Python. For example a linked list is pretty much a Python list. A double linked list too can often be faked in Python by using negative indexing. Trees are a bit more valid and do have uses in applications like heirarchical data storage such as found in file browsers, family trees, organisational charts etc. They are also very powerful tools for constructing searches of large data sets. Things like bags and sets are just heterogenous collections which Pythons native types mimic well. (Many of these concepts grew out of early languages which only allowed a single type of data in a collection) OTOH there are cases for most of these data types where there are arguments for constructing a dedicated implementation in Python is valid, but they are rare. If you have specific questions about specific types let us know and we can offer more speciofic advice. Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. If you are interested in investigating the more advanced aspects of programming I'd suggest digging into concepts like closures, locking, semaphores, predicate and lambda calculus, boolean algebra, relational data theory, functional programming, aspect oriented programming, literate programming, provable correctness (use of assertions for pre/post conditions and invariance etc), meta data. These are all of more direct relevance in higher level languages like Python. HTH, Alan G. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] please help with sqlite replace function
aivars [EMAIL PROTECTED] wrote Yes it seems you are right. The ActiveState python version I have installed have sqlite 2.3.2 only. I find it strange. Why? SQLite is a separate product. Python bundled the then current version in its standard distribution, but time has moved on. You have apparently installed a more recent version of SQLite. I see that on a python website there is is a new version Python26 2.6 may or may not have the same version as you but regardless you should be able to get the older version of Python to work with the newer SQLite instal;l, provided the newer version has a Python library available - which it usually has. Mark Hammonds PythonWin to get other things for windows? Or maybe I will reinstall ActiveState Python25 and install Python25 from the official website I don't thing the vanilla Python will make any difference. SQLite is bundled with Python not with ActiveState. Copying dll to c:\python25\DLLs directory did not help - it still shows version sqlite version 2.3.2. which I also do not understand why I think you might need to install more than the DLL. Check the SQLite web site for a new Ptython interface and install that version. Alan G. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] problem with simple sqlite script
aivars [EMAIL PROTECTED] wrote sPath=r'e:\pythonexamples\aivars2.db' con=sqlite3.connect(sPath) cur=con.cursor() cur.execute(insert into test (name) values (?),sPath) con.commit() File E:\PythonExamples\test.py, line 7, in module cur.execute(insert into test (name) values (?),sPath) ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 28 supplied. It looks like name expects a char and you are giving it a string. How did you define the name field of test? Can you send us the create statement? -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] please help with sqlite replace function
Hello, Denis, Please try what sqlite3.version shows on your machine? Thanks aivars 2008/11/7 spir [EMAIL PROTECTED]: aivars a écrit : Thanks, John, Yes it seems you are right. The ActiveState python version I have installed have sqlite 2.3.2 only. I find it strange. I also have ActiveState's python (mainly for its very good doc) and I get: import sqlite3 sqlite3.sqlite_version '3.3.4' Denis ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] pattern expressions
Hello,
I'm learning to use parsers: trying pyParsing, construct and simpleparse to
have a better overview. I know a bit regular expressions and rather used to
BNF-like formats such as used for specification of languages. But I have never
really employed them personly, so the following may be trivial. Below is used a
BNF dialect that I think is clear and non-ambiguous.
format_code := '+' | '-' | '*' | '#'
I need to specify that a single, identical, format_code code may be repeated.
Not that a there may be several one on a sequence.
format := (format_code)+
would catch '+-', which is wrong. I want only patterns such as '--', '+++',...
style_code := '/' | '!' | '_'
Similar case, but different. I want patterns like:
styled_text := style plain_text style
where both style instances are identical. As the number of styles may grow (and
even be impredictable: the style_code line will actually be written at runtime
according to a config file) I don't want, and anyway can't, specify all
possible kinds of styled_text. Even if possible, it would be ugly!
I would like to specify a side-condition for a pattern, meaning that it
should only when a specific token lies aside. For instance:
A := A_pattern {X}
X is not part of the pattern, thus should not be extracted. If X is just
garbage, I can write an enlarged pattern, then let it down later:
A := A_pattern
A_X := A X
If X itself is a token, I can write a super pattern, then extract both items
from the combination, and let down As that come alone:
X := X_pattern
A := A_pattern
A_X := A X
But what if X is part of another production? For example:
B := X B_end_pattern
A_X := A X
I tried it, but I can't get X in both productions. So that I catch either B or
A_X -- according to mysterious priority rules I don't fully understand (it
seems to be neither the longest string, nor the first written pattern, by
pyParsing).
Now, precisely, what about priority? I mean ambiguous cases, when an actual
production can match several patterns. Parsers have tricks, rules, or explicit
features to cope with such cases, but, as I understand it, these apply during
or after the parsing process, as additional treatment. Is there a way to
specify priority in the grammar itself?
Denis
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] problem with simple sqlite script
On Fri, Nov 7, 2008 at 3:49 AM, aivars [EMAIL PROTECTED] wrote: import sqlite3 sPath=r'e:\pythonexamples\aivars2.db' con=sqlite3.connect(sPath) cur=con.cursor() cur.execute(insert into test (name) values (?),sPath) The second argument to execute() is a *sequence* of parameter values. A string is a sequence of characters, so by passing a plain string you are saying that each character of the string is a parameter to the SQL. Try adding braces around the parameter to make list: cur.execute(insert into test (name) values (?), [sPath]) Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Thu, Nov 6, 2008 at 11:14 PM, [EMAIL PROTECTED] wrote: Hi everyone, I've been teaching myself python for a few months and I'm becoming frustrated because I've kind of hit a wall in terms of learning new information. You might like to read the (printed) Python Cookbook. It has many good examples of idiomatic Python in the context of solving a real problem. Also I suggest you start working on a project that interests you and learn what you need to know to complete it. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] problem with simple sqlite script
Thanks, Alan, here is a create statement: CREATE TABLE test (name TEXT) And also I would like to thank you for you web page. Classes and OOP seems to start to make sense to me now slowly after I am reading your material. Aivars 2008/11/7 Alan Gauld [EMAIL PROTECTED]: aivars [EMAIL PROTECTED] wrote sPath=r'e:\pythonexamples\aivars2.db' con=sqlite3.connect(sPath) cur=con.cursor() cur.execute(insert into test (name) values (?),sPath) con.commit() File E:\PythonExamples\test.py, line 7, in module cur.execute(insert into test (name) values (?),sPath) ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 28 supplied. It looks like name expects a char and you are giving it a string. How did you define the name field of test? Can you send us the create statement? -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Fri, Nov 7, 2008 at 4:12 AM, Eric Abrahamsen [EMAIL PROTECTED]wrote: snip Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. If you want to learn all sorts of new and exciting things, I'd suggest learning about cryptography, and writing attacks (on your own data) as a method of learning more. It's fun, challenging, and there's a real world application for it, if you happen to enjoy any type of security. my 2¢ -Wayne ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] problem with simple sqlite script
Kent, Yesss!! That did the trick! It's worth to remeber. Thank you very much! Aivars 2008/11/7 Kent Johnson [EMAIL PROTECTED]: On Fri, Nov 7, 2008 at 3:49 AM, aivars [EMAIL PROTECTED] wrote: import sqlite3 sPath=r'e:\pythonexamples\aivars2.db' con=sqlite3.connect(sPath) cur=con.cursor() cur.execute(insert into test (name) values (?),sPath) The second argument to execute() is a *sequence* of parameter values. A string is a sequence of characters, so by passing a plain string you are saying that each character of the string is a parameter to the SQL. Try adding braces around the parameter to make list: cur.execute(insert into test (name) values (?), [sPath]) Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Nov 7, 2008, at 12:14 PM, [EMAIL PROTECTED] wrote: Hi everyone, I've been teaching myself python for a few months and I'm becoming frustrated because I've kind of hit a wall in terms of learning new information. In an effort to continue to learn I've found some material on more intermediate/advanced topics like linked lists, nodes, trees, etc. However, it's kind of like reading a math textbook - the tutorials do a decent job of explaining the material but it's all kind of theoretical, and I'm not sure how I'd apply these concepts in real world applications, or incorporate them into my code. Does anyone have any suggestions for learning about real world application of more advanced concepts? Are you writing real-world applications and using them? My (admittedly limited) experience has taught me that the real complexities of programming don't lie in obscure data structures or rarely-used functions, but in the practical, real-world issues that arise from creating actual applications: OOP best practices, application architecture, programming paradigms, recurring patterns, even just plain-old programming gotchas (though there are fewer of these in Python than other languages, thankfully). In other words, stuff that isn't necessarily described in the manuals, but that becomes evident once you've made the same mistakes two or three times, and start thinking about modifying your approach to programming. I've never used a tree, and a heap only once, but I feel like I've dipped into some pretty mind-bending stuff in terms of how I've arranged programs. Take metaclasses, for instance: no description of metaclasses I've read ever made sense to me; it only started to come clear after I'd looked at a module I was writing, realized that there was something really fundamentally wrong with it, and then slowly realized that the answer was metaclasses. About eleven lines of metaclass programming, as it turned out, but those seven lines turned my brain inside out for a bit. Not boring in the least! Yrs, Eric Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. Thanks, Ben ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Fri, Nov 7, 2008 at 4:12 AM, Alan Gauld [EMAIL PROTECTED] wrote: For example a linked list is pretty much a Python list. Other than the very different timing characteristics! Python lists are O(1) for reading or writing a value at an index, O(n) for inserting and deleting. Linked lists are O(n) for reading and writing and O(1) for insertion and deletion (at a known location). Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to use function from specific module and then switch to other module
Classification: UNCLASSIFIED Caveat (s): FOUO Kent, Thanks for the lead. I eventually did something like the Strategy Pattern you sent. It was so much simpler when I just inherited the functions. I think I need to redesign the code but for now it works and my boss will be happy. Thanks again. John Ertl Meteorologist FNMOC 7 Grace Hopper Ave. Monterey, CA 93943 (831) 656-5704 [EMAIL PROTECTED] Classification: UNCLASSIFIED Caveat (s): FOUO From: Kent Johnson Sent: Thu 11/6/2008 7:36 PM To: Ertl, John C CIV 63134 Cc: tutor@python.org Subject: Re: [Tutor] How to use function from specific module and then switch to other module On Thu, Nov 6, 2008 at 5:54 PM, Ertl, John C CIV 63134 [EMAIL PROTECTED] wrote: Classification: UNCLASSIFIED Caveat (s): FOUO I have a program that collects weather data from weather models. I originally had a module that contained a bunch of function that I used. So I just added it to the init of the class I was using and inherited the functions. That worked great but now I have two different models that I can get weather from. Each Module A and B have the exact same function names in them but they both do slightly different things. It might help to see a working example of what you did for one model. The idea is as I step through a list I want to use a different function (same name but from a different module) for each element in the list. How do I have a generic way to do this. for example for point 1 I want to use the rain function from Module A and then for point 2 I want to use the rain function from Module B. At first though I would just init the class from either A or B for each point but I need the function from A or B to be able to use function from my main program...that is why the inheritance thing worked great for just one module. Don't try to make the model A and B into base classes of the forecast. Just pass the forecast object to the model. So your rain() method will look more like this: def rain(self, fc): fc.calTime() # this function is in the main forecast class fc.rain = do stuff for model A where fc will be the forecast instance. You might also be able to use simple functions rather than classes: def rain(fc): fc.calTime() # this function is in the main forecast class fc.rain = do stuff for model A then just call moduleA.rain(self) or moduleB.rain(self). You might want to read about the Strategy pattern, that is what you are doing. Here is a Python example of a class-based Strategy. http://mail.python.org/pipermail/python-list/2006-April/379188.html This example passes the strategy to the constructor but you can set it in your pointInfo() method if you like. I would just make one function to handle each point though: for each in x.pointList: x.handlePoint(each) where def handlePoint(self, point): pointStrategy = ... pointStrategy.rain(self, point) Kent Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Torrent
___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Thu, 06 Nov 2008 23:14:38 -0500, btkuhn wrote: Hi everyone, I've been teaching myself python for a few months and I'm becoming frustrated because I've kind of hit a wall in terms of learning new information. In an effort to continue to learn I've found some material on more intermediate/advanced topics like linked lists, nodes, trees, etc. However, it's kind of like reading a math textbook - the tutorials do a decent job of explaining the material but it's all kind of theoretical, and I'm not sure how I'd apply these concepts in real world applications, or incorporate them into my code. Does anyone have any suggestions for learning about real world application of more advanced concepts? Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. There is really no ceiling in learning programming. The problem is to find a problem. If you're bored, you can do the practically-for-bored- programmers challenges like Python Challenge (http:// www.pythonchallenge.com/) or Project Euler (http://projecteuler.net/ index.php?section=view) If you're up to the challenge and responsibility, you could join an open source program teams or start one yourself. Alternatively, you could also start learning some embedded python flavors, like the one used by OpenOffice.org or Inkscape, these provides different challenge to vanilla python as you've got to learn their libraries. If you think you're bored of python, perhaps it is time to start learning another language. Having many programming language in your toolbox is certainly a life-saver, since some problems are easier to solve in certain languages than other. For example, many mathematical problems are (much) easier to express in functional language, like Haskell, compared to imperative language. Other languages might have features/paradigm that are foreign in python, like Eiffel's Programming by Contract. You might also start seeing domain-specific languages, like SQL (database), XSLT (XML), (E)BNF (syntax parsing), etc. Alternative languages you might consider: Haskell, Prolog, Eiffel, C- family, Perl, Lisp-family, APL-family, some assembly, shell scripting (bash, bat, etc) If you're EXTREMELY bored though, you might learn some of the more esoteric languages, e.g. Shakespeare, Piet, Whitespace, etc (be ready to abandon all sanity) ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] pattern expressions
Paul McGuire a écrit :
Question 1:
format_code:= '+' | '-' | '*' | '#'
I need to specify that a single, identical, format_code code may be
repeated.
Not that a there may be several one on a sequence.
format := (format_code)+
would catch '+-', which is wrong. I want only patterns such as '--',
'+++',...
This interpretation of '+' in your BNF is a bit out of the norm. Usually
this notation 'format_code+' would accept 1 or more of any of your
format_code symbols, so '+-+--++' would match.
That's what I intended to write above. (format_code)+ would catch '+-', which
is wrong. I need a pattern that matches a repetition of the same token, this
token beeing an item of a set. Of course, I could write a pattern for each
token... but it is supposed to be programming, not cooking ;-)
What I'm looking for is a format that may not exist:
format := (format_code)++
where '++' means 'repetition of an identical token'
In pyparsing, you could match things like '' using the Word class and
specifying a string containing the single character '-': Word('-'). That
is, parse a word made up of '-' characters. There is no pyparsing construct
that exactly matches your (format_code)+ repetition, but you could use Word
and MatchFirst as in:
format = MatchFirst(Word(c) for c in +-*#)
That's it! I had not realized that, as pyparsing is real puthon, one can also
use python idioms /inside/ the grammar... good! thank you. So that it is also
possible to have variables, no? Then, my question #2 should be solved, too.
A corresponding regular expression might be:
formatRE = '|'.join(re.escape(c)+'+' for c in +-*#)
which you could then parse using the re module, or wrap in a pyparsing Regex
object:
format = Regex(formatRE)
Question 2:
style_code := '/' | '!' | '_'
Similar case, but different. I want patterns like:
styled_text:= style plain_text style
where both style instances are identical. As the number of styles may grow
(and even be impredictable: the style_code line will actually be written at
runtime according to a config file) I don't want, and anyway can't, specify
all possible kinds of styled_text. Even if possible, it would be ugly!
pyparsing includes to methods to help you match the same text that was
matched before - matchPreviousLiteral and matchPreviousExpr. Here is how
your example would look:
plain_text = Word(alphanums + )
styled_text = style + plain_text + matchPreviousLiteral(style)
(There is similar capability in regular expressions, too.)
Good, thank you again. Do you know if there is any way to express such things
in ordinary E/BNF, or in any dialect coming from BNF? It's like a variable
inside a pattern, and I personly have never seen that.
Pattern variables would also be very helpful as (said before) I need to write
or at least reconfigurate the grammar at runtime.
Question 3:
I would like to specify a side-condition for a pattern, meaning that it
should only match when a specific token lies aside. For instance:
A := A_pattern {X}
X is not part of the pattern, thus should not be extracted. If X is just
garbage, I can write an enlarged pattern, then let it down later:
A := A_pattern
A_X:= A X
I think you might be looking for some kind of lookahead. In pyparsing, this
is supported using the FollowedBy class.
A_pattern = Word(alphas)
X = Literal(.)
A = A_pattern + FollowedBy(X).leaveWhitespace()
print A.searchString(alskd sldjf sldfj. slfdj . slfjd slfkj.)
prints
[['sldfj'], ['slfkj']]
I guess there is the same for left-side conditions. I'm going to search myself.
This guy who develops pyParsing thinks at everything. There are so many helper
functions and processing methods -- how can you know all of that by heart, Paul ?
Denis
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] pattern expressions
On Fri, Nov 7, 2008 at 4:22 PM, spir [EMAIL PROTECTED] wrote: This guy who develops pyParsing thinks at everything. There are so many helper functions and processing methods -- how can you know all of that by heart, Paul ? Maybe because he *is* the guy who develops pyparsing? ;-) Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] please help with sqlite replace function
aivars [EMAIL PROTECTED] wrote Please try what sqlite3.version shows on your machine? I also have ActiveState's python (mainly for its very good doc) and I get: import sqlite3 sqlite3.sqlite_version '3.3.4' Me too with Python 2.5.1 from Activestate. Alan G ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
Kent Johnson [EMAIL PROTECTED] wrote For example a linked list is pretty much a Python list. Other than the very different timing characteristics! True, but its pretty rare that timing issues are a reason for me to choose a data structure - especially if I need to hand code it! :-) Python lists are O(1) for reading or writing a value at an index, O(n) for inserting and deleting. Linked lists are O(n) for reading and writing and O(1) for insertion and deletion (at a known location). I would say O(1) only if you already have a reference to that location (ie its known in that sense) but if you know that it's at position 23 but you only have a reference to the head you still need to navigate sequentially to the 23rd element so its still an O(n). O(1) only applies when inserting at the next position to where you currently are. That's not too common a scenario in my experience. But the geneal point is a good specific example (and I was struggling to think of one!) where you might choose a non standard list over the vanilla version. The array module is another case where performance is improved over the standard lists. Alan G. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] problem with simple sqlite script
CREATE TABLE test (name TEXT) OK, That looks fine. con=sqlite3.connect(sPath) cur=con.cursor() cur.execute(insert into test (name) values (?),sPath) Try putting the string variable in a tuple: cur.execute(insert into test (name) values (?), (sPath,) ) That seems to work for me... HTH, Alan G. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] gnuplot from a python gui
Hello tutors, I'm trying to generate a plot using gnuplot from within a python gui. In Windows, if after the plot is drawn I use a raw_input string demanding a 'RETURN' be hit, the plot will persist on the screen until the 'RETURN' is pressed. In *nix, one can use the 'persist' switch to easily and much more elegantly accomplish the same. My question is, is there a better way IN WINDOWS to keep the plot on the screen rather than having to leave the gui and find the console window in which a 'RETURN' must be pressed to continue? My gui will not 'quit' until I enter the 'RETURN' in the console window. Kind of a chintzy way to end the gui, really. There must be a better way than using raw_input??? Daniel B. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Fri, Nov 7, 2008 at 6:16 PM, Alan Gauld [EMAIL PROTECTED] wrote: True, but its pretty rare that timing issues are a reason for me to choose a data structure I would guess you commonly choose a dict or set over a list when you need fast tests for membership. Failure to choose dict when appropriate is certainly a common cause of performance problems. But the geneal point is a good specific example (and I was struggling to think of one!) where you might choose a non standard list over the vanilla version. The array module is another case where performance is improved over the standard lists. The standard lib also includes collections.deque (O(1) insertion and deletion at both ends) and heapq (binary priority queue). Third party implementations of b-tree, avltree and trie are available which have better performance than list and dict for some usage. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] cgi scripts
I want to print a list of the keys and their values passed to a cgi script by an HTML form. I have tried this, but just seems to crash. Any ideas? Jim Morcombe #!C:\python25\python.exe import cgi, sys # import cgitb; cgitb.enable() #Send errors to browser sys.stderr = sys.stdout #Parse data from form data = cgi.FieldStorage() #Send response to browser print Content-type: text/html\n print titleCGI Form Response/title\n print h2This is the data passed to the cgi script/h2P print These are the keys\n print br print for k in data.keys(): print key: , k, value: , data[k] ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] cgi scripts
Jim Morcombe wrote: I want to print a list of the keys and their values passed to a cgi script by an HTML form. I have tried this, but just seems to crash. When you say crash, what do you mean, exactly? Any ideas? print Content-type: text/html\n print titleCGI Form Response/title\n print h2This is the data passed to the cgi script/h2P It wouldn't hurt to output fully-formed HTML here. print for k in data.keys(): I think you'll find the source of your problem right about here. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
