Re: [Tutor] DB design
Liam Clarke wrote: Anyway, why don't you tell us more about what you are trying to do and we can give better suggestions. Kent Database organised - Client details Jobs Finances | | | Costs Resolutions It will go by client#/ and job# to reference various bits. Hi Liam, I am not a proficient Python nor OO programmer but I know my way around databases and SQL. I believe that before you can fully jump into coding or even writing SQL queries for your project, you need to get to know relational databases lingo and what your subject refers to: DB Design. Basically you need to organize your data into different tables or "entities" and then build relationships around them. You need ot identify how each entity relates to each other. Database designers usually refer to this as an entity-relationship diagram. For example, your entity (table) Clients describes certain attributes (fields) each one has. The kind of relationship the entity Client can have to the entity Jobs is that "one Client can hold one or more Jobs" (or in this case "none to many jobs"). So you define the relationship between entity Clients and Jobs to be a "none or one-to-many" relationship. Additionally, there can be "one-to-one" relationships or "many-to-many" (e.g. People to Jobs). I do not know the functionality you want to get from your application, but that will take you to define the kind of relationships you can build from there. Schematically this has its own representation, but I prefer to direct you to some of the links I just found through googling a little bit. For example, look into: http://miner.chem.purdue.edu/Lectures/Lecture23.pdf which is very high level. It does not describe the details in the lecture, but helps as a first hand intro http://r937.com/relational.html More desccriptive, particularly an explanation of what normalization is, and how to approach the database design process. Anybody have any other references or suggestions relating to the subject? About Python, I assume (experts please jump in) you will build a class for each entity, and any record of the entity or table becomes a class instance. I hope this helps. Victor Bouffier Finance Manager www.grupoandersons.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Need script help with concept
I am in the process of building a script but I do not know if what I am trying to do is possible. So, long story short, I need help. The concept: I am want to be able to ask the user a series of questions in the program window. But here is the action I want to appear on the screen. 0. Question pops up 1. User inputs answer 2. User press enter 3. The first question and answer is replaced with a new question on the screen 4. User answers the second question 5. User press enter 6. Question and answer disappears 7. etc. All user inputs are placed in a variable. Please help. :-) ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Help on python file extension windows vista recognition
Please, I need help. I installed python on my gateway windows vista laptop computer. This is with the latest version of python (Python 2.6.3 Windows installer) Python 2.6.3 Windows installer I have some python code files I placed on my desktop and tried placing it in a folder containing python program. The files still appears on the computer as a text file. Even though I placed the .py file extension on the file. The .py is on the file but the icon image appears as a notepad file. I need help in resolving this issue. Thanks _ Hotmail: Trusted email with Microsoft’s powerful SPAM protection. http://clk.atdmt.com/GBL/go/177141664/direct/01/___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] carriage return on windows
Orri Ganel wrote: Jacob S. wrote: Thanks Kent and Max! Wow, I didn't know it did that. I'm too dumb to figure it out on my own I guess... Oh well! I found a cool new thing to play with at least! Thanks, Jacob On Jan 30, 2005, at 02:40, Jacob S. wrote: I don't think that's what he wants. I think he wants to *overwrite* what's in the shell with new output. For example. so that the whole line is overwritten. In my experience, this is not possible and if anyone can show me how to do it, I would be grateful. HTH, Jacob It *is* possible, that's exactly what my code does (well, as long as you don't run it on Mac OS 9). The carriage return (\r, as opposed to the linefeed \n) moves the cursor to the beginning of the *current* line. -- Max maxnoel_fr at yahoo dot fr -- ICQ #85274019 "Look at you hacker... A pathetic creature of meat and bone, panting and sweating as you run through my corridors... How can you challenge a perfect, immortal machine?" ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor Just a note: This does not work on IDLE, so for those who try this and are frustrated when it fails, try it in the dos-box (command prompt). I played around with this output issue and I love the way it works. Now, how do you do this in *nix? I tried the same approach and I get a blank line for 5 seconds (or whatever number of cycles you have on your example) and the a final line with the last value of the iterable. Do you happen to know how this in done? Thanks. Victor worked around this problem and I love the solution. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] carriage return on windows
Michael Janssen wrote:
On Mon, 31 Jan 2005 18:01:59 -0600, Victor Rex <[EMAIL PROTECTED]> wrote:
I played around with this output issue and I love the way it works.
Now, how do you do this in *nix? I tried the same approach and I get a
blank line for 5 seconds (or whatever number of cycles you have on your
example) and the a final line with the last value of the iterable.
Do you happen to know how this in done?
you might want to flush stdout after printing to it. "print" will
cares for this only when not using that trailing comma. "flush" means
to write immedatly instead to wait for a fair amount of data.
import sys,time
for i in range(8):
sys.stdout.write( "step: %s\r" % i)
# or: print "step: %s\r" % i,
sys.stdout.flush()
time.sleep(.5)
There's still another possibilty using ansi control sequences. The
dirty way is to print (without trailing comma) and go back to previous
line:
import time
for i in range(8):
print "step: %s\033[A" % i
# print subsystem has done stdout.flush
time.sleep(.5)
It's dirty cause the next line was already entered and thus is written
(as an empty line) and content of older "steps" will stay an screen,
when subsequents lines aren't long enough to overwrite them. Which
also applies to \r:
import sys,time
for i in range(8,0,-1):
# printing 8**8, ..., 0**0 on line. Forget to overwrite
sys.stdout.write( "step: %s\r" % (i**i))
sys.stdout.flush()
time.sleep(.5)
Fixes are to add whitespace to the line. Stepping back with \033[D
fixes the empty newline issue (which is most often not worth the
effort):
import sys,time
for i in range(8,0,-1):
# fixing output length to 30
output = "%-30s" % "step: %s" % (i**i)
length = len(output)
sys.stdout.write(output)
# "print output," would be different, because of implizit spaces
sys.stdout.write("\033[D"* (length))
sys.stdout.flush()
time.sleep(.5)
regards
Michael
Excellent. Thanks Kent and Michael.
Great tutorial ;-)
You're right Michael. This last one works nicely but it is probably not
worth the effort.
I likes the previous one but adding fixed formatting to the number
output, something like
"step: %9s\r"
instead of just
"step: %s\r".
Thanks again.
Victor
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Re: [Tutor] Presentation
This is a great series of links. I found the following on Pythology too: Python Spotting http://pythonology.org/spotting Best of luck. Kent Johnson wrote: Eric Raymond's "Why Python?" essay is a classic: http://pythonology.org/success&story=esr Bruce Eckel's "Why I love Python" presentation is here: http://64.78.49.204/pub/eckel/LovePython.zip This page has lots of links you might be interested in: http://www.ferg.org/python_presentations/index.html This page has links to language comparisons: http://www.python.org/moin/LanguageComparisons Good luck! Kent Paul Hartley wrote: I am trying to get Python established here in the Philippines. Currently I am in charge of operations at a business based in Manila and I have asked my IT staff to start using Python (with some success). A local university has now asked that I give a talk to their IT people on Python - so here is an opportunity to spread the word and get some more converts and maybe introduce python into their computer science courses. Any help I can get would be much appreciated - such as language comparisons, companies and systems that use python, debates about what python is good for (almost everything), examples of elegant code.. When I was a member of the Forth Interest Group in the USA we learned that Forth was used on the buggy that went to mars, that it started life controlling huge radio telescopes which only had 4k (yes 4k) of memory for both language and application. Anything like the above concerning python would be useful. Any other suggestions would help also, the audience will have computers, so a demonstration of small workshop would also be good - the presentation/session is for 4 hours on the 10th February. Paul ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] MySQLdb error while inserting records
Hi all, I consider myself fairly proficient with SQL, but I'm still getting the hang of the MySQL API. I am working through the examples in "Open Source Web Development with LAMP: Using Linux, Apache, MySQL, Perl, and PHP" by James Lee and Brent Ware, and trying to make the third "P" to be Python. :) There is an example in the book which is written in Perl, used to insert new records to MySQL. I tried it as it is written and it works fine. I have migrated to Python another example that gets all of the records in the age_information table (SELECT query), and it is getting the data successfully. However, I am having problems with the program to insert records. The following is my modified code in Python: -- 1 #!/usr/bin/python 2 # connect.py 3 4 import sys 5 import MySQLdb 6 7 if len(sys.argv) != 4: 8 print "You have to enter lastname, firstname and age\n" 9 sys.exit(1) 10 11 # This is to change the age type from str to int 12 last, first, strAge = sys.argv[1:] 13 age = int(strAge) 14 15 # Some debugging lines 16 print last, first, age 17 print type(last), type(first), type(age) 18 print 19 #sys.exit() 20 21 22 try: 23 conn = MySQLdb.connect(host='localhost', 24 user='apache', passwd='LampIsCool', db='people') 25 except: 26 print "Could not connect\n" 27 sys.exit(1) 28 29 c = conn.cursor() 30 31 # prepare the SQL, exit() if the preparation fails 32 query = ''' 33 INSERT INTO age_information 34 (lastname, firstname, age) 35 VALUES (?, ?, ?) 36 ''' 37 38 # execute the SQL 39 records = c.execute(query, (last, first, age)) 40 if records >= 1: 41 print "Succesfully inserted %d records" % records 42 else: 43 print "Could not insert anything, sorry." 44 45 c.commit() 46 c.close() 47 conn.close() 48 -- Executing the script from the command line, I get the following output: -- $ ./insert.py Cool Joe 13 Cool Joe 13 Traceback (most recent call last): File "./insert.py", line 39, in ? records = c.execute(query, (last, first, age)) File "/usr/lib/python2.3/site-packages/MySQLdb/cursors.py", line 95, in execute return self._execute(query, args) File "/usr/lib/python2.3/site-packages/MySQLdb/cursors.py", line 110, in _execute self.errorhandler(self, TypeError, m) File "/usr/lib/python2.3/site-packages/MySQLdb/connections.py", line 33, in defaulterrorhandler raise errorclass, errorvalue TypeError: not all arguments converted during string formatting ------ I was getting this same error so I entered lines 12 and 13 to change the age from type string to integer. No change. Do you know what am I missing? Thanks to all. -- Victor Bouffier Finance Manager www.grupoandersons.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] MySQLdb error while inserting records
Yes! That did it. I got confused since Programming Python mentions the '?' for arguments, although I failed to notice it was just used as an example. Actual identifiers could vary depending on the database. Thanks a lot Kent. Kent Johnson wrote: Victor Bouffier wrote: Hi all, I consider myself fairly proficient with SQL, but I'm still getting the hang of the MySQL API. I am working through the examples in "Open Source Web Development with LAMP: Using Linux, Apache, MySQL, Perl, and PHP" by James Lee and Brent Ware, and trying to make the third "P" to be Python. :) There is an example in the book which is written in Perl, used to insert new records to MySQL. I tried it as it is written and it works fine. I have migrated to Python another example that gets all of the records in the age_information table (SELECT query), and it is getting the data successfully. However, I am having problems with the program to insert records. According to this page http://sourceforge.net/docman/display_doc.php?docid=26238&group_id=22307 MySQLdb uses the 'format' style of passing parameters to SQL, not the questionmark style you have used below. So change query to >32 query = ''' >33 INSERT INTO age_information >34 (lastname, firstname, age) >35 VALUES (%s, %s, %s) >36 ''' Kent -- Victor Bouffier Finance Manager www.grupoandersons.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Paradox database files
Hi all. Does anybody know of a Python module to read from Paradox database files? I don't need to write back to the files. These files are being exported using a proprietary application and I need to parse them to extract transaction information. I found something about ODBC being able to connect to several database types, but I am not even sure how this would work with Paradox. Any OS solution you suggest works fine for me, since I have access to both a unix (linux) box and Python on Windows too. Thanks. -- Victor Bouffier Finance Manager www.grupoandersons.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Paradox database files
Hi all, I know this is OT from Python, but does anybody know how to fix my library issues. I get some awkward dependencies issues from these pylib libraries. # rpm -Uvh pxlib-0.4.3-1.i386.rpm error: Failed dependencies: libbz2.so.1.0 is needed by pxlib-0.4.3-1.i386 but when I look into my libraries I find the necessary ones under /usr/lib: # ll /usr/lib/libbz2* -rwxr-xr-x 1 root root 67594 Jun 15 2004 /usr/lib/libbz2.a lrwxrwxrwx 1 root root11 Feb 6 11:02 /usr/lib/libbz2.so -> libbz2.so.1 lrwxrwxrwx 1 root root15 Feb 6 10:10 /usr/lib/libbz2.so.1 -> libbz2.so.1.0.2 lrwxrwxrwx 1 root root24 Mar 8 09:41 /usr/lib/libbz2.so.1.0 -> /usr/lib/libbz2.so.1.0.2 -rwxr-xr-x 1 root root 71724 Jun 15 2004 /usr/lib/libbz2.so.1.0.2 I created the second-to-last symlink with no success. I also added '/usr/lib' to /etc/ld.so.conf as suggested in a newsgroup. I've got a Fedora Core3 with both apt and yum installed, and both tell me I've got the latest libraries (bzip2-libs). If you believe I should post my question elsewhere, please let me know. Thanks. Victor apple_py wrote: ---Original Message--- From: "Danny Yoo" <[EMAIL PROTECTED]> Subject: Re: [Tutor] Paradox database files Sent: 08 Mar 2005 01:51:35 On Mon, 7 Mar 2005, Victor Bouffier wrote: > Does anybody know of a Python module to read from Paradox database > files? I don't need to write back to the files. These files are being > exported using a proprietary application and I need to parse them to > extract transaction information. Hi Victor, You might be interested in 'pxview': http://pxlib.sourceforge.net/pxview.html which can extract CSV-formatted files out of Paradox Database files. Once you have your data in CSV format, then Python's "csv" module can come into play: http://www.python.org/doc/lib/module-csv.html Alternatively, you might be able to use the pxlib Python bindings directly. According to: http://pxlib.sourceforge.net/documentation.php?manpage=pxlib a Python binding exists somewhere out there, though I haven't been able to find it yet... ok, found it, but it appears you might need to check it out of CVS: http://cvs.sourceforge.net/viewcvs.py/pxlib/bindings/ so this might not be as easy to use right out of the box. ---Original Message--- ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor -- Victor Bouffier Finance Manager www.grupoandersons.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Paradox database files
That did the trick. Thanks Ewald. FYI, I used the '--nodeps' directive once I realized there were really no major issues. I still needed to keep the added symlink since the px libraries couldn't find the libbz2.so.1.0 file. Thanks again to all. That was great help. Victor Ewald Ertl wrote: Hi Victor on Tue, 08 Mar 2005 10:06:50 -0600 Victor Bouffier <[EMAIL PROTECTED]> wrote : ----- Victor Bouffier > Hi all, Victor Bouffier > I know this is OT from Python, but does anybody know how to fix my Victor Bouffier > library issues. I get some awkward dependencies issues from these pylib Victor Bouffier > libraries. Victor Bouffier > Victor Bouffier > # rpm -Uvh pxlib-0.4.3-1.i386.rpm Victor Bouffier > error: Failed dependencies: Victor Bouffier > libbz2.so.1.0 is needed by pxlib-0.4.3-1.i386 Victor Bouffier > Victor Bouffier > but when I look into my libraries I find the necessary ones under /usr/lib: Victor Bouffier > Victor Bouffier > # ll /usr/lib/libbz2* Victor Bouffier > -rwxr-xr-x 1 root root 67594 Jun 15 2004 /usr/lib/libbz2.a Victor Bouffier > lrwxrwxrwx 1 root root11 Feb 6 11:02 /usr/lib/libbz2.so -> libbz2.so.1 Victor Bouffier > lrwxrwxrwx 1 root root15 Feb 6 10:10 /usr/lib/libbz2.so.1 -> Victor Bouffier > libbz2.so.1.0.2 Victor Bouffier > lrwxrwxrwx 1 root root24 Mar 8 09:41 /usr/lib/libbz2.so.1.0 -> Victor Bouffier > /usr/lib/libbz2.so.1.0.2 Victor Bouffier > -rwxr-xr-x 1 root root 71724 Jun 15 2004 /usr/lib/libbz2.so.1.0.2 Victor Bouffier > Perhap's there is a problem with the RPM-Database. I don't know how rpm works internaly, but it controls somewhere in a "database", which packages are installed on the system. On an old SuSE-System I can search, to which package a file belongs rpm -q -f /usr/lib/libbz2.so bzip2-1.0.2-103 Here I see, that libbz2.so belongs to the bzip2-Package. The other way is to list the files belonging to a package: rpm -q -l bzip2-1.0.2-103 /usr/bin/bunzip2 /usr/bin/bzcat /usr/bin/bzip2 /usr/bin/bzip2recover /usr/include/bzlib.h /usr/lib/libbz2.a /usr/lib/libbz2.la /usr/lib/libbz2.so /usr/lib/libbz2.so.1 /usr/lib/libbz2.so.1.0.0 During the installation/update-Process, I think, rpm looks up, all dependencys mentioned in the rpm if they are installed on the system via the "database" where it logs, what is installed. Try if you can get a package to which your /usr/lib/libbz2.so.1 belongs. The other way is, to install the rpm-Package without depdency-check's, but this could result in the availability of the pxlib-Package, but it perhaps does not work. You've to test this, before you keep the package. "rpm -Uvh --nodeps" This should ignore the dependencies and install the package. --- end -- HTH Ewald ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor -- Victor Bouffier Finance Manager www.grupoandersons.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] visibility of variables
Hello all of you, I have problems with the visibility of variables in python. I am used to the idea of Javascript and other languages where one can define global variables if they are defined outside a function. It seems Python is not doing that, but how can I make it work? I think it needs some twist in my mind to get used to it, but I still don't grasp it. Can you help? I have attached a program that is not functioning as I would like to have it functioning. It seems that the 'gementenkleur' in funct1 and funct2 are the value of gemetenkleur at the start of the program, but they don't chance after the definition of gemetenkleur=bmifrao1.bmp I 'know' this is something particular to Python, by how can I work around this? I could add gemetenkleur in the argument list of the funct1 and funct2 functions, but in my case I don't want this (funct1 will be a function to be used in scipy.fmin, and I have the idea that only the simplex can be as an argument). Is there a good page on the web that described this visibility issue (or does it have a different name?) of Python? The delveintopython.pdf does not help me and also a tutorial of hetland.org (Instant python: instant-python.php.htm ) seems not to speak the right language for me;-). Hope someone can help me. I have the idea this is essential to understand before continuing more in Python. All the best, Victor bmifrao1bmp=[(41, 37, 33), (63, 56, 53), (107, 97, 92), (228, 226, 222), (81, 64, 107), (107, 131, 82), (236, 207, 71), (158, 58, 42)] print 'original bmifrao1bmp ',bmifrao1bmp #gemetenkleur=[(41, 37, 33), (63, 56, 53), (107, 97, 92), (228, 226, 222), (81, 64, 107), (107, 131, 82), (236, 207, 71), (158, 58, 42)] gemetenkleur=[[47,46,47],[62,65,61],[116,114,114],[238,233,232],[65,62,116],[0,144,75],[245,211,0],[207,65,60]] endkleur=[[47,46,47],[62,65,61],[116,114,114],[238,233,232],[65,62,116],[0,144,75],[245,211,0],[207,65,60]] def funct1(): print 'gemetenkleur in func1: ',gemetenkleur a=funct2(gemetenkleur) def funct2(kleuren): print 'kleuren in funct2 (should be same as gemetenkleur): ',kleuren return 1 def Do(): gemetenkleur=bmifrao1bmp[:] print 'gemetenkleur has to be from now bmifrao1bmp: ',gemetenkleur funct1() Do() ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] visibility of variables
THANKS Kent. It seems I used the wrong keywords to find answer to my question. This page is very very helpfull! I now works indeed. THANKS for your fast help. All the best, Victor Kent Johnson wrote: >>I have problems with the visibility of variables in python. I am >>used to the idea of Javascript and other languages where one can define >>global variables if they are defined outside a function. It seems Python >>is not doing that, but how can I make it work? >> >>I think it needs some twist in my mind to get used to it, but I still >>don't grasp it. Can you help? > > In function Do() you must add the declaration > global gemetenkleur > > See > http://www.python.org/doc/faq/programming.html#how-do-you-set-a-global-variable-in-a-function > and the entry that follows it for some explanation. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] print a line in IDLE as bold, italics or a color
Hello all of you, I am trying to simply(?) print some text in a print statement as bold (or itlaics or an certain color). How do I do this in python? Browsing the web gives we all kind of soluation, but non seem to work (a lot are related when printing on the web). Say I want to print the text (in the mentioned format): This is bold, red, blue, italics How do I do this in python 2.2 and using IDLE? Thanks for your help. All the best, Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] print a line in IDLE as bold, italics or a color
Hello Danny, Danny Yoo wrote: >>This is in a seperate text box, but I want to have the colors >>(bold/italics) in the default IDLE window. > > This will probably be more difficult. I don't believe IDLE itself allows > a user's program to set its own fonts and colors within the running IDLE > window. > > I'm sure it's technically possible, but not without some significant > hacking at the IDLE interface. Error messages in IDLE also get a color (red), so it loooks to be standard 'IDLE'/python;-) Also IDEL recognize keywords while typing and changes the color (to orange), so it is quite normal in IDLE... But now; how can user's python program use it? All the best, Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] print a line in IDLE as bold, italics or a color
Hello Alan, Thanks for your feedback. I managed to get some color in my print in IDLE (or the Paint Shop Pro Script Output window): ### import sys print >> sys.stderr,'Hello world' ### All the best, Victor Alan G wrote: > Is there any reason why you want to change the ouput only in IDLE? > Or do you really want to be able to control the output of your > program wherever it runs? If the latter then you will need to > create your own Text window and display the output there. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] print a line in IDLE as bold, italics or a color
Hello Alan, Alan G wrote: >> Thanks for your feedback. I managed to get some color in my print in >> IDLE (or the Paint Shop Pro Script Output window): > > I'm intrigued. Does PSP now support scripting in Python? > Is that a standard feature? (I'm a Photoshop Elements user > myself...) It is python (I wonder even if the system itself is not python;-), because the calls to PSP routines are kind of Python calls... I am working on this: http://www.iol.ie/~geniet/eng/pspscripthelp.htm All the best, Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] dialog boxes
Hello all of you, I want to use yes/no-, text-, info-, checklist- dialog boxes in my image manipulation program (on a Windows XP Pro system using python 2.2 and 2.3). What is the best way to do this? Thanks for your feedback. All the best, Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] dialog boxes for Windows
Hello all of you, I want to use yes/no-, text-, info-, checklist- dialog boxes in my image manipulation program (on a Windows XP Pro system using python 2.2 and 2.3). What is the best way to do this? Do peopel have some examples or links? I want to know which python modules are needed and where to get. Thanks for your feedback. All the best, Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Python debugger bummer
Hi to all, I tried to look for a reference to this issue in the ASPN archive, but I can't seem to find an answer. I currently work under Linux and have never been able to properly use the Python debugger. Coming from a Perl background, I fail to find a similar simple way to step through my code the way I am able to do it through the -d flag using Perl on the command line. It is so painless. I have used Python on Windows, usually writing my programs using Vim, and entering the PythonWin environment to debug my programs. It is a good environment to do that, although I prefer my independent editor for writing my programs. I once paid for ActiveState's Komodo for Linux to use as an IDE, but I find it bloated and slow, not to mention the need to constantly upgrade if you want to keep up with versions (have not done it yet). Does anyone have any suggestions as to an alternative to PythonWin, or even better still, a reference to a good tutorial on how to use my current tools: how to use the python debugger as the way Perl debugger works? I am certain the Python interpreter (being better that Perl in that sense) must have a way to use the debugger. I work under Linux using vi/gvim and ipython (I have never really tried IDLE). Thanks in advance for any help. Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Python debugger bummer
Hi again, I was going through the Python library documentation and I found something I never saw before. $ python -m pdb myscript.py This is what I was looking for! Great help. Any further reference could of course help a lot. I never was able to get the hang of it until now. Victor On Mon, 2006-01-16 at 13:12 -0600, Victor Bouffier wrote: > Hi to all, > > I tried to look for a reference to this issue in the ASPN archive, but I > can't seem to find an answer. > > I currently work under Linux and have never been able to properly use > the Python debugger. Coming from a Perl background, I fail to find a > similar simple way to step through my code the way I am able to do it > through the -d flag using Perl on the command line. It is so painless. > > I have used Python on Windows, usually writing my programs using Vim, > and entering the PythonWin environment to debug my programs. It is a > good environment to do that, although I prefer my independent editor for > writing my programs. > > I once paid for ActiveState's Komodo for Linux to use as an IDE, but I find it > bloated and slow, not to mention the need to constantly upgrade if you > want to keep up with versions (have not done it yet). > > Does anyone have any suggestions as to an alternative to PythonWin, or > even better still, a reference to a good tutorial on how to use my > current tools: how to use the python debugger as the way Perl debugger > works? I am certain the Python interpreter (being better that Perl in > that sense) must have a way to use the debugger. > > I work under Linux using vi/gvim and ipython (I have never really tried > IDLE). > > Thanks in advance for any help. > Victor > > > ___ > 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] Python debugger bummer
Thanks Alan. As always, you are very helpful. Victor On Mon, 2006-01-16 at 23:35 +, Alan Gauld wrote: > > I was going through the Python library documentation and I found > > something I never saw before. > > > > $ python -m pdb myscript.py > > I was just about to suggest loading pdb... > > And of course there is also a graphical debugger in IDLE as > well as PythonWin. > > The paper version of my book contains a chapter > (not on the web site) on how to use pdb to debug a script. > pdb has its limitations but if you are used to gdb then its > not too bad. > > (pdb) help > > is your friend. > > Alan G > Author of the learn to program web tutor > http://www.freenetpages.co.uk/hp/alan.gauld > > ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] string object into reference
Pujo, I think your solution does not address Kirk's problem. You don't mention the addition of surface areas. If for any reason he had more than two types of amino acids, then he would need to use a dictionary for the totals, with each key being a specific amino acid. The actual steps to follow are: 1. open the file to read 2. initialize the dictionary to empty 3. for each line in the file 4. see if the key for that amino acid already \ exists in the dictionary 5. if it does not exist, create a new dictionary \ key for that new amino acid, and initialize it \ to zero 6. add the surface area of the current line to the \ corresponding dictionary key 7. print the totals dictionary Kirk, I would write the program (would take me less time), but the idea is for yo uto learn to program in Python ;-) Post your code for review. Regards. Victor On Tue, 2006-01-17 at 22:08 +0100, Pujo Aji wrote: > Hello Kirk, > > If I'm not mistaken your idea is referencing two columns: first column > is your acid name and the later is your surface area. > Later you want to connect the surface area if you name the acid name. > If that what you want another question arises... is your acid name is > unique. > If it is you can make dictionary types. > > A csb > B dsk > C dsk > > you can create > mydic = [] > mydic['A'] = 'csb' > mydic['B'] = 'dsk' > mydic['C'] = 'dsk' > > you have to transform the file into a list and after that start > building the dictionary variable. > > After this dictionary variable is filled. you can get the surface area > by typing the acid name such as: > print mydic['A'] # will result 'csb' > > Cheers, > pujo > > On 1/17/06, Kirk Vander Meulen <[EMAIL PROTECTED]> wrote: > Hi, just joined. I've got a question that I'm guessing > there's a ridiculously easy answer to, but I'm having trouble > (no excuses, I'm just dumb!)... > > My problem is I want to make a string object into a reference > to another object. To be more specific, I'm reading through a > text file of amino acids. The first item on each line is the > amino acid name, and a later item is its exposed surface area. > For each amino acid, I want to add up the surface area as I go > through the text file. So what I'm doing is, for each line, > assigning the reference 'residue' to the amino acid name. I'd > like to then make the string referred to by 'residue' (eg, > 'CYS' or 'TRP') a reference to an object that I will > subsquently increment by the surface area value. > > Thanks for any help. Perhaps I just need to be pointed to a > relevent thread or given the correct words to search for in > the archives or manual. > > Kirk > > ___ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor > > > > ___ > 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] string object into reference
Ooops. Did not respond to the mailing list.
Here is my replied-to post.
--
Hi Kirk,
There is nothing as a dumb question.
I am assuming your source file will have a amino acid residue ('CYS' or
'TRP'), followed by a space, and then the corresponding surface area.
You have to define a variable for adding the surface areas of each
residue type.
As you only have one of two options, the easiest way is to define a
variable for each (e.g. cys, trp) and then open the file and process
each line, adding the surface area to the corresponding amino acid.
As for reference, look for working with files (I/O), string variable
splitting (split function), and basic operations to add each new surface
area.
Try writing some code and posting it back. Would be glad to review it.
Victor
On Tue, 2006-01-17 at 11:50 -0600, Kirk Vander Meulen wrote:
> Hi, just joined. I've got a question that I'm guessing there's a
> ridiculously easy answer to, but I'm having trouble (no excuses, I'm
> just dumb!)...
>
> My problem is I want to make a string object into a reference to
> another object. To be more specific, I'm reading through a text file
> of amino acids. The first item on each line is the amino acid name,
> and a later item is its exposed surface area. For each amino acid, I
> want to add up the surface area as I go through the text file. So
> what I'm doing is, for each line, assigning the reference 'residue' to
> the amino acid name. I'd like to then make the string referred to by
> 'residue' (eg, 'CYS' or 'TRP') a reference to an object that I will
> subsquently increment by the surface area value.
>
> Thanks for any help. Perhaps I just need to be pointed to a relevent
> thread or given the correct words to search for in the archives or
> manual.
>
> Kirk
> ___
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Re: [Tutor] Dictionaries [Was: Re: string object into reference]
Hi Danny,
On Tue, 2006-01-17 at 16:03 -0800, Danny Yoo wrote:
> > > My problem is I want to make a string object into a reference to
> > > another object. To be more specific, I'm reading through a text file
> > > of amino acids. The first item on each line is the amino acid name,
> > > and a later item is its exposed surface area.
>
> These kind of "bulk" questions are fairly easy to answer if we collect all
> the key-value pairs in a single dictionary container, because we're just
> asking that one container.
>
> But it's much harder to answer this if we use individual variables for
> each key-value pair, since we don't tell the system that those variables
> are somehow related as a group --- as far as Python knows, they're just
> disconnected variables.
>
I couldn't agree more. I love using dictionaries. I don't know why I
suggested individual variables instead of the usage of a dictionary in
the first place.
>
> The terminology that the original poster uses ("references to another
> object") sounds a lot like the original usage of symbolic "soft"
> references in Perl.
> (http://www.perl.com/doc/manual/html/pod/perlref.html)
>
> Perl programmers, for the most part, avoid them now because they're so
> error prone. So if the original poster is thinking about symbolic
> references, then we should encourage the poster to look into dictionaries,
> since dictionaries are a fairly direct replacement for that usage.
>
I did not know Perl programmers were moving away from references. That's
new to me, and an interesting point.
On the other hand, Kirk's comment about "references to another object"
takes us into a discussion over references, when we actually should be
focusing on Perl's hashes (or references to hashes for that matter).
Or better still, get away from Perl and start programming in Python and
use dictionaries instead! ;-)
> Best of wishes!
>
Thanks a lot.
Victor
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Re: [Tutor] References and list aliasing in Perl and Python [Was: Re: Dictionaries]
On Tue, 2006-01-17 at 22:57 -0800, Danny Yoo wrote:
> > > The terminology that the original poster uses ("references to another
> > > object") sounds a lot like the original usage of symbolic "soft"
> > > references in Perl.
> > > (http://www.perl.com/doc/manual/html/pod/perlref.html)
> > >
> > > Perl programmers, for the most part, avoid them now because they're so
> > > error prone. So if the original poster is thinking about symbolic
> > > references, then we should encourage the poster to look into
> > > dictionaries, since dictionaries are a fairly direct replacement for
> > > that usage.
> > >
> > I did not know Perl programmers were moving away from references. That's
> > new to me, and an interesting point.
>
> [Note: I'll write some Perl code below. Probably bad, nonidiomatic Perl
> code. I also have a high chance of saying something wrong. If I do so,
> someone please correct me. *grin*
>
> Also, whenever I say "Perl", I'll mean Perl 5 --- I understand that Perl 6
> has a model that's similar to Python now.]
>
>
> Hi Victor,
>
> No, no, I'd better clarify this to try to avoid someone getting angry at
> me. Maybe I'll dig myself into a deeper hole, but oh well.
>
> Perl has a distinction between "soft" symbolic references and "hard"
> references. I think symbolic references may have been a language mistake;
> I think good Perl style these days has been to phase them out of usage.
>
> Perl programmers seem to be perfectly happy with "hard" references:
> (http://search.cpan.org/~nwclark/perl-5.8.7/pod/perlreftut.pod)
>
>
> Python programmers like myself struggle a little when we talk about this
> because, truthfully, we don't think about this much. In Python, we pass
> references around without with abandon: we might not even realize it!
> Values in Python are all references. For example:
>
> ### Python ###
> >>> msg = list("hello world");
> >>> greeting = msg
> >>> id(msg)
> 466880
> >>> id(greeting)
> 466880
> ##
>
> In Python, both 'msg' and 'greeting' are names that refer to the same list
> value. We see this because they have the same id(). And if we apply
> mutation on the list value, we'll see this from both names:
>
> ### Python ###
> >>> msg[1] = 'a'
> >>> msg
> ['h', 'a', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd']
> >>> greeting
> ['h', 'a', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd']
> ##
>
>
>
> Perl makes a distinction between values and references to those values, so
> the following shows different results:
>
> ### Perl #
> mumak:~ dyoo$ cat > test.pl
> my @msg = split //, "hello world";
> my @greeting = @msg;
> print [EMAIL PROTECTED], "\n";
> print [EMAIL PROTECTED], "\n";
> $msg[1] = 'a';
> print "@msg\n";
> print "@greeting\n";
>
> mumak:~ dyoo$ perl -w test.pl
> ARRAY(0x180b560)
> ARRAY(0x180b5b4)
> h a l l o w o r l d
> h e l l o w o r l d
> ##
>
> Here, we see that @msg and @greeting are really separate things in Perl:
> the values are in different memory locations, and assignment copies the
> data structures around.
>
>
> To get the same aliasing effect as in Python, we'd have to explicitely ask
> Perl to reference and dereference:
>
> ### Perl ###
> my $msg = [split //, "hello world"];
> my $greeting = $msg;
> print $msg, "\n";
> print $greeting, "\n";
> $msg->[1] = 'a';
> print "@$msg\n";
> print "@$greeting\n";
> #
>
> So Perl folks have a slightly more complex conceptual model: they make a
> distinction bewteen values and references. Python just has references.
>
> There are tradeoffs here. On the one hand, Python folks get caught off
> guard when they first encounter list aliasing. On the other, Perl folks
> get caught off guard when they first try to make a hash whose values are
> themselves lists. *grin*
>
WOW. Great explanation. Don't worry about a deeper hole.
Your examples once again reminded me of one of reasons I started looking
into Python instead of continuing with Perl. It is not the
functionality, but the convoluted scripts can get. One can hardly
understand the code.
Thanks again.
Victor
>
> Hope this helps!
>
>
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Re: [Tutor] [Re] Fwd: Strings backwards
This was just posted by John Fouhy (snipped part of it):
Basically, the syntax is [start:stop:step].
If step is negative, you work backwards. eg:
>>> string.lowercase[20:10:-2] # letters 20, 18, 16, 14, 12
'usqom'
And if you omit the start or stop parameters, and step is
negative,
then start defaults to the end of the list and stop to the
beginning.
So string.lowercase[::-1] will step backwards, starting at the
end and finishing at the start.
So to reverse a string, you would only need to do the following:
>>> print 'hello world'[::-1]
dlrow olleh
I had to do the string-to-list-then-reverse-string-then-back-to-string
process myself before knowing about this marvelous operand.
It works on tuples (all immutable objects) too:
>>> digits = (0,1,2,3,4,5,6,7,8,9)
>>> print digits[::-1]
(9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
Best of Luck
Victor
On Thu, 2006-01-19 at 08:26 +0100, János Juhász wrote:
> Hi Ryan,
>
> I just extended Adam's code with a speech-to-text recepi from
> http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/114216.
>
> On 18/01/06, ryan luna <[EMAIL PROTECTED]> wrote:
> >
> > Hello, what i need to do is get user input and then
> > print the string backwards ^^ i have no idea how to do
> > that,
> >
> > print "Enter a word and i well tell you how to say it
> > backwards"
> >
> > word = raw_input("Your word: ")
> >
> > print word
> >
> > all that is simple enough im sure printing it out
> > backwards is to, just dont know how ^^, thanks for any help.
>
> import sys
> from win32com.client import constants
> import win32com.client
> import string
>
> speaker = win32com.client.Dispatch("SAPI.SpVoice")
> print "Type word or phrase, then enter."
> print "Ctrl+Z then enter to exit."
>
> def backword(word):
>l = list(word)
>l.reverse()
>return ''.join(l)
>
> def backsentence(sentence):
>words = sentence.split(' ')
>words = [backword(word) for word in words]
>return ' '.join(words)
>
> while 1:
>try:
> s = raw_input()
> rev = backsentence(s)
> print 'I would say: ', rev
> speaker.Speak(rev)
>except:
> if sys.exc_type is EOFError:
> sys.exit()
>
> It works on my xp :)
>
>
> Yours sincerely,
> __
> János Juhász
>
> ___
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>
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Re: [Tutor] References and list aliasing in Perl and Python [Was: Re: Dictionaries]
On Wed, 2006-01-18 at 23:03 -0800, Danny Yoo wrote: > > > There are tradeoffs here. On the one hand, Python folks get caught > > > off guard when they first encounter list aliasing. On the other, Perl > > > folks get caught off guard when they first try to make a hash whose > > > values are themselves lists. *grin* > > > > > WOW. Great explanation. Don't worry about a deeper hole. > > > > Your examples once again reminded me of one of reasons I started looking > > into Python instead of continuing with Perl. It is not the > > functionality, but the convoluted scripts can get. One can hardly > > understand the code. > > Hi Victor, > > That might be an unfair judgement. > > One can write really convoluted and ugly programs in any programming > language. And although I do think that our choice in what programming > language we us can affect a program's clarity, I also believe that people > matter much more than the programming language. > > Otherwise, what would be the point of a mailing list like this? *grin* > > > Best of wishes! > > Yes, it is true. Take care. Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] [Re] Fwd: Strings backwards
On Thu, 2006-01-19 at 16:49 -0500, Orri Ganel wrote: > Victor Bouffier wrote: > > >I had to do the string-to-list-then-reverse-string-then-back-to-string > >process myself before knowing about this marvelous operand. > >It works on tuples (all immutable objects) too: > > > [SNIP] > > Not all immutable objects, just those that define __getslice__ > (basically, those that use indexes: sequences). Ints, for example, are > immutable and don't work: > > >>> 12[::-1] > > Traceback (most recent call last): > File "", line 1, in -toplevel- > 12[::-1] > TypeError: unsubscriptable object > > > - Orri > I see. Thanks for the correction Orri Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Linux Python install?
I highly recommend you have a look into ipython. It is a breeze to work with. I usually have a couple of terminal screens open, one with the ipython interpreter, which helps me a lot when testing code snipplets. You can install it using yumex, or just run 'yum install ipython' from the root command line. If you just started with Fedora, go into this site and follow the tips provided. It really improves your working environment. It will also provide you with extra repositories which allow you the installation of ipython among other packages. Fedora Core 4 Tips and Tricks http://home.gagme.com/greg/linux/fc4-tips.php On Mon, 2006-01-23 at 10:06 -0500, Python wrote: > On Mon, 2006-01-23 at 09:28 -0500, CPIM Ronin wrote: > > Sorry to bother the list with so simple a question but on moving to Linux > > from Windows XP, it's not clear to me how to accomplish a Python install > > on > > Linux. On XP it was mostly point and click on a ".msi" file (with msi > > standing for Microsoft install). I've loaded the latest Fedora/Redhat > > release on an old AMD machine. How do I install Python such that it shows > > up > > as a selection under the Programming task bar with EMACS? > > I assume you are using yum for package management. It should have been > installed by default. As root, you can issue the command > yum install python python-docs python-devel python-tools > > The package yumex provides a GUI interface to the yum package manager. > You can think of yumex as the Windows "Add/Remove Programs" application > on steroids. > yum install yumex > > The yumex install view with a filter of > python > will provide an extensive list of additional python packages. > > Finally, I do not know if this includes the best python integration with > EMACS. > > > I assume I have to do this under root, right? > > > > Step by step please. > > > > Thanks. > > > > _ > > Dont just search. Find. Check out the new MSN Search! > > http://search.msn.click-url.com/go/onm00200636ave/direct/01/ > > > > ___ > > 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] Dictionaries
Hi Alan and Ken, I think know the difference between using items() vs. iteritems() and their equivalent for keys and values. I notice Ken suggests iteritems(), while Alan suggests items() only. Does one approach have an advantage over the other? Should we use only one of them favorably? Thanks. Victor On Thu, 2006-01-26 at 13:43 +, Alan Gauld wrote: > > How would I modify this to just print either the values or keys? > > Just ask for the values or the keys! > > for value in pairs.values() > print value > > for key in pairs.keys() > print key > > for key,value in pairs.items() > print key > print value > ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Dictionaries
On Fri, 2006-01-27 at 13:20 -0500, Kent Johnson wrote: > It doesn't make much difference for small dictionaries. keys(), values() > and items() create new lists with the specified elements. iterkeys(), > itervalues() and iteritems() create iterators that return the specified > elements in sequence. So for the common case of iterating over dict > elements with a for loop, the 'iter' variants conserve memory and may be > faster (but always check!) because of the cost of creating the list. > > The iter variants are relatively new (since Python 2.2). I used to use > the older variants in examples here so I wouldn't have to explain the > difference :-) but ISTM that modern usage is heading to prefer the iter > versions and I am starting to use them myself. > > But I guess you will not notice any difference in performance until you > have dicts with many thousands of elements. > > Kent > Hi Kent and Alan, Thanks to both for your response. Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Splitting long string into same len parts
Hi to all, I'd like to split a long string into equally long strings (len(str) = 3). I did the following using regexes: >>> n = 'xb1jyzqnd1eenkokqnhep6vp692qi9tmag3owzqw0sdq3zjf' >>> o = re.split(r'(...)', n) >>> print o ['', 'xb1', '', 'jyz', '', 'qnd', '', '1ee', '', 'nko', '', 'kqn', '', 'hep', '', '6vp', '', '692', '', 'qi9', '', 'tma', '', 'g3o', '', 'wzq', '', 'w0s', '', 'dq3', '', 'zjf', ''] Which gives me empty strings between each value. So to actually have this working I ended up filtering through a list comprehension: >>> o = [ x for x in re.split(r'(...)', n) if x ] >>> print o ['xb1', 'jyz', 'qnd', '1ee', 'nko', 'kqn', 'hep', '6vp', '692', 'qi9', 'tma', 'g3o', 'wzq', 'w0s', 'dq3', 'zjf'] This is what I needed. Is there an easier or more straightforward way to do this? Thanks. Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Splitting long string into same len parts
Hi Emile and John, Thanks a lot for your insight. There is always a better way, or at least a more pythonic one. Take care. Victor. On Wed, 2006-02-08 at 22:36 -0800, Emile van Sebille wrote: > "Andre Roberge" <[EMAIL PROTECTED]> wrote in message > > > There's a tongue-in-cheek quote that I really like: > > "Sometimes you have a programming problem and it seems like the best > > solution is to use regular expressions; now you have two problems." > > +1 -- There are some things re is good for, but mainly it's good > motivation to just do it in python... > > > n = 'xb1jyzqnd1eenkokqnhep6vp692qi9tmag3owzqw0sdq3zjf' > > length = len(n) > > o = [] > > for i in range(0, length, 3): > > o.append(n[i:i+3]) > > > > Or as a one-liner... > > o = [ n[ii:ii+3] for ii in range(0,len(n),3) ] > > Emile > > > > > ___ > 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] Splitting long string into same len parts
WOW!! This is really great. Thanks Ken. This first one is definitely going to my personal scripts directory ;-) Victor On Thu, 2006-02-09 at 05:56 -0500, Kent Johnson wrote: > Victor Bouffier wrote: > > Hi to all, > > > > I'd like to split a long string into equally long strings (len(str) = > > 3). > > This is a very popular topic in the Python Cookbook. See for example > http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/425044 > http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/439095 > > and the links in the comments for the first recipe above. > > Kent > > ___ > 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] Splitting long string into same len parts
Aha!!! I believe this is what I was looking for in the first place (not that I will use it anyway, given the alternatives provided by others). I guess that coming from a Perl background, which as you know includes regexes as part of the core language, you tend to look to all solutions through this lens. I faced this problem before and solved it using regexes but could not remember how. Your re.findall() suggestion is nice though. Very clean. Thanks Danny. On Wed, 2006-02-08 at 18:55 -0800, Danny Yoo wrote: > > On Wed, 8 Feb 2006, Victor Bouffier wrote: > > > Hi to all, > > > > I'd like to split a long string into equally long strings (len(str) = > > 3). I did the following using regexes: > > > > >>> n = 'xb1jyzqnd1eenkokqnhep6vp692qi9tmag3owzqw0sdq3zjf' > > >>> o = re.split(r'(...)', n) > > >>> print o > > ['', 'xb1', '', 'jyz', '', 'qnd', '', '1ee', '', 'nko', '', 'kqn', '', > > 'hep', '', '6vp', '', '692', '', 'qi9', '', 'tma', '', 'g3o', '', 'wzq', > > '', 'w0s', '', 'dq3', '', 'zjf', ''] > > > > Which gives me empty strings between each value. > > Hi Victor, > > Try using re.findall() instead of re.split(). The behavior you're seeing > with split is perfectly logical: each pair of empty strings is being split > by that three-character sequence. > > > Best of wishes! > > ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Splitting long string into same len parts
On Thu, 2006-02-09 at 09:45 +, Alan Gauld wrote: > > Define easier :-) > Right! > You could just use string slicing and a stepsize of 3 in range: > > lst = [mystring[index : index+3] for index in range(0,len(mystring),3)] > Ever since I found them, list comprehensions are my favorites. > ... and you still have problems where the > string is not exactly divisible by 3, should you add padding? > Alan, I understand where you are coming from. However, in this case I don't have a problem since the incoming string will always be divisible by 3, in this particular case. Thanks for pointing it out though. Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Iterating over a string: index and value
On Fri, 2006-02-10 at 12:42 -0800, Carroll, Barry wrote:
> I seem to recall reading somewhere that it is possible to concurrently
> generate the index and value of a string’s characters in a single for
> statement. Is this true or did imagine it?
>
>
>
> Here is the scenario:
>
>
>
> Given an ASCII string of arbitrary length and content, generate a
> sequence of tuples whose elements are:
>
> the index of each character in the string, and
>
> data based on the ordinal value of the character in the ASCII
> collating sequence.
>
Hi Barry,
Have a look at enumerate:
>>> list(enumerate('abcdefghijk'))
[(0, 'a'),
(1, 'b'),
(2, 'c'),
(3, 'd'),
(4, 'e'),
(5, 'f'),
(6, 'g'),
(7, 'h'),
(8, 'i'),
(9, 'j'),
(10, 'k')]
You need to work on each tuple in the iterable, but the function takes
you halfway.
Hope it helps.
Victor
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Re: [Tutor] Guessing a number with limited no. of tries game gone wrong.
Hi Ros,
Look what happens when the user tried for more than 5 times:
if tries > 5:
break
This just takes you out of the loop, but it does not handle the issue
that the user did not guess correctly. The next statement will be to
print the congratulations message.
You should instead tell the user they did not make it and exit the
program altogether, probably letting them know what the actual number
was. Something like:
if tries > 5:
print "Too bad. You tried one too many times."
print "The number was", the_number
sys.exit()
You have to 'import sys' first though.
Try it out and analyze the flow of the program. Use the debugger to try
your code one step at a time to see what is going wrong.
I would also change the initial guess to specify the range, like:
guess = int(raw_input("Take a guess between 1 and 100: "))
Best of luck.
Victor
On Tue, 2006-03-28 at 12:20 -0500, Ros Daniel wrote:
> I am a newbie at Python. Just bought Python Programming 2nd ed. by Michael
> Dawson. While I understand the concepts as the book is going through the
> code, and I am able get the same results, when it comes to applying what
> I've learned to the exercises at the end of each chapter, I seem to be
> stumped. I think my logic is off somehow. I am able to get the program to
> work if it's just a case of the user guessing the random number, and then
> being told they guessed correctly in a certain number of tries. It's when
> the user has a limited number of guesses that I am stumped. Either I get an
> infinite loop, or the program will say I guessed right in a certain number
> of tries, but the guess is not correct
>
> Can anyone explain to me what I'm missing and doing wrong? Thanks.
>
> # Modify the Guess My Number game so that the player has a limited number of
> guesses. If the player fails to guess in time, the program should display an
> appropriately chastising message.
>
>
>
> import random
>
> print "Welcome to the new and improved 'Guess My Number' game."
> print "This time you have a limited number of guesses, so guess wisely.\n"
>
>
> the_number = random.randrange(100) + 1
>
> guess = int(raw_input("Take a guess: "))
> tries = 1
>
> # guessing loop
> while (guess != the_number):
> if tries > 5:
> break
> elif guess > the_number:
> print "Lower..."
> elif guess < the_number:
> print "Higher..."
>
> guess = int(raw_input("Guess again:"))
> tries += 1
>
>
> # message of congratulations
> print "You guessed it! The number was", the_number
> print "And it only took you", tries, "tries!\n"
>
>
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Re: [Tutor] Bigrams and nested dictionaries
On Wed, 2006-03-29 at 00:15 -0500, Michael Broe wrote:
> Aha! John wrote:
>
> "Are you sure you haven't mistakenly assigned something other than a
> dict to D or D['d'] ?"
>
> Thanks for the tip! Yup that was it (and apologies for not reporting
> the problem more precisely). I hadn't initialized the nested
> dictionary before trying to assign to it. (I think Perl doesn't
> require initialization of dictionaries prior to assignment, which in
> this case, would be a nice thing...)
>
> >>> D['c']['a'] = 1 #ooops
> Traceback (most recent call last):
>File "", line 1, in ?
> KeyError: 'c'
> >>> D['c'] = {}
> >>> D['c']['a'] = 1
> >>> D
> {'a': {'a': 1, 'b': 2}, 'c': {'a': 1}}
>
You can check if the dictionary key exists prior to assigning to it:
>>> if not D.has_key('c'):
...D['c'] = {}
>>> D['c']['a'] = 1
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Re: [Tutor] Bigrams and nested dictionaries
On Mon, 2006-04-03 at 11:39 -0700, Danny Yoo wrote:
> > You can check if the dictionary key exists prior to assigning to it:
> >
> > >>> if not D.has_key('c'):
> > ...D['c'] = {}
> > >>> D['c']['a'] = 1
>
>
> Hi Victor,
>
> Another approach is to use the badly-named "setdefault()" method which is
> a close analogue to Perl's "autovivification" feature:
>
> ##
> >>> D = {}
> >>> D.setdefault('c', {})['a'] = 1
> >>> D
> {'c': {'a': 1}}
> ##
>
> Good luck!
>
Thanks to both Danny and Alan.
Great tips.
Victor
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[Tutor] Extending a list within a list comprehension
Hi all,
I have solved my problem, but would like to know if what I accomplished
can be done with different data using list comprehensions.
the list I want to sort has the following format:
elements = [
(codigo, [ cant, importe, porc]),
(codigo, [ cant, importe, porc]),
...
]
Actual data is:
In [129]: elements[0:5]
Out[129]:
[('2712', [22.0, 3618.80999, 0.0032389476163069883]),
('2713', [19.0, 6551.81004, 0.0058640739309320719]),
('2710', [21.0, 2553.57999, 0.0022855336019435113]),
('2716', [19.0, 8215.27004, 0.0073529224203034461]),
('4305', [4.0, 348.37, 0.00031180199598565978])]
And I want to sort descending on 'importe', which is x[1][1] for x in
elements.
What I did was the following, following the Schwarzian Transform:
temporal = []
temporal = [ [x[1][1], (x[0], description[x[0]],
x[1][0], x[1][1], x[1][2] ) ] for x in elements ]
temporal.sort()
temporal.reverse() # sort descending
elements = [ x[1] for x in temporal ]
If the second element in each array passed as x is of variable length
(that is, it has a different element count than three, in this case),
the program needs to extend the list instead. Without list
comprehensions, and the added capability to utilize and sized list as a
second element, my code ended up looking like the following:
temporal = []
for x in elements:
lst = [x[0], description[x[0]]]
lst.extend(x[1])
temporal.append([x[1][1], lst])
temporal.sort()
temporal.reverse() # sort descending
elements = [ x[1] for x in temporal ]
Is there a way to use list comprehensions to append or extend the array
as needed by the second code listing?
Thanks.
Victor
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[Tutor] [Fwd: Re: Extending a list within a list comprehension]
I sent this to John directly. Posting to the list. Forwarded Message From: Victor Bouffier <[EMAIL PROTECTED]> To: John Fouhy <[EMAIL PROTECTED]> Subject: Re: [Tutor] Extending a list within a list comprehension Date: Tue, 11 Apr 2006 18:03:41 -0500 On Wed, 2006-04-12 at 10:29 +1200, John Fouhy wrote: > On 12/04/06, Victor Bouffier <[EMAIL PROTECTED]> wrote: > > elements = [ > > (codigo, [ cant, importe, porc]), > > (codigo, [ cant, importe, porc]), > > ... > > ] > > > > And I want to sort descending on 'importe', which is x[1][1] for x in > > elements. > > In python 2.4, you could achieve this by saying: > > elements.sort(key=lambda x: x[1][1]) > > In earlier versions of python, you can do: > > elements.sort(lambda x, y: cmp(x[1][1], y[1][1])) > > (but this is less efficient than key= in 2.4) > > There's also the decorate-sort-undecorate idiom: > > dec = [(x[1][1], x) for x in elements] > dec.sort() > elements = [x[1] for x in dec] Hi John, Thanks for your help. This is very nice and I will definitely use it when sorting a fixed list. However, I forgot to point out I am including an extra element: item description from a dict, where its key=codigo (x[0]). This is why I write the whole list as a single element. Still I could follow your suggestion and do: dec = [(x[1][1], x, description[x[0]]) for x in elements] dec.sort() elements = [x[1], x[2] for x in dec] It is still better, but not quite there. Any feedback will be gladly taken. Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Extending a list within a list comprehension
On Tue, 2006-04-11 at 23:42 +0100, Alan Gauld wrote: > Hi Victor, > > I've gotta say that I much prefer the second version here. > > > temporal = [] > > temporal = [ [x[1][1], (x[0], description[x[0]], > >x[1][0], x[1][1], x[1][2] ) ] for x in elements ] > > temporal.sort() > > temporal.reverse() # sort descending > > elements = [ x[1] for x in temporal ] > > > > > > temporal = [] > > for x in elements: > >lst = [x[0], description[x[0]]] > >lst.extend(x[1]) > >temporal.append([x[1][1], lst]) > > temporal.sort() > > temporal.reverse() # sort descending > > elements = [ x[1] for x in temporal ] > > > > That looks a lot easier to rtead (and debug) and will I suspect be > easier to maintain. Copmprehensions are great but unfortunately > can rapidly become incomprehensible! > > > Is there a way to use list comprehensions to append or extend the array > > as needed by the second code listing? > > There may be but I wouldn't try. > I might however look at using a simple list or dictionary of objects based > on a class... It might be easier. > > Alan G > > Hi Alan, I believe you are right. The most pythonic way is not always the most "perlish" way ;-) (no offense intended to Perl-comers, but Perl does tend to promote nesting of expressions). It is much easier to read and maintain, which is what I will need to do eventually. Thanks for the feedback. Victor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Decorators
On Tue, 2006-04-11 at 21:08 +0100, Alan Gauld wrote: > What was an easy to learn and use, ideal language > for medium sized to fairly large scripting projects is trying to turn > into > an all encompassing general purpose language which will be > increasingly difficult to use without falling down some new syntax > hole. Alan, I could not agree more. Python's has both simplicity in its syntax and very powerful constructs like generators and object orientation included. I would hate to eventually need a Python reference book by my side for even the simplest of projects because I could not remember $#& meant a returned value from a function when the value was a particular type (I used to work with Perl and you can get into that pretty quickly). ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Extending a list within a list comprehension
On Tue, 2006-04-11 at 22:17 -0400, Kent Johnson wrote: > Victor Bouffier wrote: > > > If the second element in each array passed as x is of variable length > > (that is, it has a different element count than three, in this case), > > the program needs to extend the list instead. Without list > > comprehensions, and the added capability to utilize and sized list as a > > second element, my code ended up looking like the following: > > > > temporal = [] > > for x in elements: > > lst = [x[0], description[x[0]]] > > lst.extend(x[1]) > > temporal.append([x[1][1], lst]) > > temporal.sort() > > temporal.reverse() # sort descending > > elements = [ x[1] for x in temporal ] > > > > Is there a way to use list comprehensions to append or extend the array > > as needed by the second code listing? > > I think you are looking for > temporal = [ [x[0], description[x[0]]] + x[1] for x in elements ] > Hi Kent, I try this one and get the following error: TypeError: list objects are unhashable I figured it is because of the x[0] element being used as a dict key. Can you explain further where this error comes from? Are you getting it too? > but I would make two steps, one for the sort using just >[ (x[0], x) for x in elements ] > You are right. This is cleaner and not a big deal to do in two steps. However for the issue at hand, it still keeps x as a two element list: [codigo, [ cant, importe, porc]], which I would like to have extended: [codigo, cant, importe, porc] It is not a big deal. That is why I finally went with the longer version Alan suggested. Before the sort I get a two element list, the second element being the list I finally want as output. > then when you pick the data back out you can format it how you like. > Right. After the sort I just get that second element in another list comprehension lines = [ x[1] for x in temp ] Thanks for your help. Victor > > Kent > > PS to John: the original solution is using DSU, aka Schwarzian Transform > > ___ > 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] dictionary datatype
On Tue, 2006-04-11 at 22:37 -0500, Jason Massey wrote:
> Works for me:
>
> >>> dict1 = { 0x2018:u'k', 0x2019:u'd'}
> >>> n = 0x2018
> >>> print dict1[n]
> k
> >>>
>
> On 4/11/06, kakada <[EMAIL PROTECTED]> wrote:
> Hello all,
>
> For example, I have a dictionary:
> dict1 = { 0x2018:u'k', 0x2019:u'd'}
>
> I assign:
> n = 0x2018
> print dict1[n]
>
> Then:
> KeyError: '0x2018'
>
> But I can call directly:
> print dict1[0x2018]
>
> So, what is wrong with this? How can I solve it?
>
> Thx
>
> kakada
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Look into the value of n after assignment:
In [285]: n = 0x2018
In [286]: n
Out[286]: 8216
n is taken as an integer containing the decimal number 8216, which in
hex is represented as 0x2018.
Try again to see if you did not mistakenly typed dict1['0x2018'] or else
defined n as such.
If you try dict1[n], dict1[0x2018], or dict1[8216] you get a correct
result, since the integer variable 'n' contains that value. Trying
dict1['0x2016'] gives you the error because the key does not exist.
define dict1 as:
dict1 = { 0x2018:u'k', 0x2019:u'd'}
and then display it whole:
In [299]: print dict1
{8216: u'k', 8217: u'd'}
Can you see your '0x2018' key anywhere?
HTH
Victor
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[Tutor] Need Help in installing MySQLdb-Python
I have Python 2.6.3 I went to the following link http://pypi.python.org/pypi/ Found - file (MySQL-python 1.2.3) clicked on file - clicked on (MySQL-python-1.2.3.tar.gz) unzipped the file in a created folder clicked on the file called setup.py following ERROR: Traceback (most recent call last): File "C:\Users\victor\Desktop\mysql-python\MySQL-python-1.2.3\setup.py", line 15, in metadata, options = get_config() File "C:\Users\victor\Desktop\mysql-python\MySQL-python-1.2.3\setup_windows.py", line 7, in get_config serverKey = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, options['registry_key']) WindowsError: [Error 2] The system cannot find the file specified I read the READ ME file I do not understand it ... I need some step by step on how to install this. -- What I am trying to do is create a window in which I input data which is stored and updated on MySQL. MySQL is on a paid server (Yahoo). any books or documentation or help would be greatly appreciated. Victor___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Need help on Setup.py
I have been trying to add some of the extras with python such as pywin32 and others. when i click on setup.py it does not work. I need help on the problem. Victor___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] scripts search
Hello I am fairly new to python. I have a small business and I wanted to use python in my business. I have a need for an Employee Time and Attendance software. Is there any python scripts out there that can do the trick? Victor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
