Re: [Tutor] Reading and Manipulating XML Data
"Luis Galvan" wrote little foggy to me, which is where I need help. The 'net always gives me an exaggerated technical answer that is simply way over my head, so I'm asking, does parsing mean to read and manipulate data? If not, can someone provide an answer in lay man's terms? Others are better qualified than me to answer this but I'll have a go anyway... Parsing is about taking raw datya and making sense of it.. To try to turn a stream of data into meaningful tokens or values. The stream needs to be in a clearly defined structure (such as XML or a programming language grammar). The parser reads the stream and breaks it into meaningful values, such as tags etc for XML. It will usually build these up as a tree structure so that you can navigate the tree to locate sopecific bits of information. Thats as simple as I can describe it. If that's too basic come back with more specific questions. The last part of my question brings me back to the first part of this message. I can't seem to find any documentation on the internet that is ideal to the beginning programmer regarding XML parsing. Have you read the ElementTree tutorial by Fred Lundh? Its fairly comprehensive and etree comes as opart of the standard Python library. I'd certainly recommend etree over minidom! http://effbot.org/zone/element-index.htm ...what are some decent python xml parsing guides out there? Any help is much appreciated! You could try reading Text Processing in Python which is a book but also available online at: http://gnosis.cx/TPiP/ HTH, -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Need to be pointed in the right direction for fileorganisation.
"Mac Ryan" wrote While I am working my way up to a more pythonic and cleaner style in the code, one thing that I have very confused ideas about is how I should organise my code, in terms of classes and files. I don't think there is any definitive answer. - Put reusable components into modules. - Don't necessarily create a module per class, but rather gather related classes into a single module. - Build modules "bottom up" so that depenedencies tend to go one way, with higher level modules importing lower level ones. Beyond that there are many different approaches to organisation. They all have strengths and weaknesses. The good news is that Python is such a high level language that you rarely have projects with so many modules that you need to create sophisticated directory structures. Usually everything can fit in one project folder. (Zope, Django etc being good examples of exceptions! :-) -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] What kind of number is this
Emad Nawfal (9E'/ FHAD) wrote: Hi Tutors, I have a bunch of text files that have many occurrences like the following which I believe, given the context, are numbers: ١٨٧٢ ٥٧ ٢٠٠٨ etc. So, can somebody please explain what kind of numbers these are, and how I can get the original numbers back. The files are in Arabic and were downloaded from an Arabic website. I'm running python2.6 on Ubuntu 9.04 Those are standard html encodings for some Unicode characters. Skipper has identified one of them as the digit '1' written in Arabic. I presume the others will also be recognizable to you, since you apparently know Arabic. The following text should be copied to a flie with extension .html Then you run that in a browser, to see the characters. DaveA Test Arabic Characters Table of characters 1632 - ٠ 1633 - ١ 1634 - ٢ 1635 - ٣ 1636 - ٤ 1637 - ٥ 1638 - ٦ 1639 - ٧ 1640 - ٨ 1641 - ٩ ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Syntax Problem
Jesse Harris wrote:
for d in Decks.all(): #loop thru all available decks
self.response.out.write(''+d.name)
self.response.out.write(''+d.description)
self.response.out.write('')
self.response.out.write('')
: invalid syntax (main.py, line 206)
args =
('invalid syntax', (r'C:\Program Files\Google\google_appengine\bangagears2\main.py', 206, 78,
"
\t\tself.response.out.write(''+d.description)\n"))
filename =
r'C:\Program Files\Google\google_appengine\bangagears2\main.py'
lineno =
206
message =
''
msg =
'invalid syntax'
offset =
78
print_file_and_line =
None
text =
"
\t\tself.response.out.write(''+d.description)\n"
There are so many things wrong I'm not sure where to begin.
This excerpt of code isn't nearly enough to compile, since it references
lots of symbols not defined. And it's not formatted the same as your
original. Your original definitely had tabs in it, as well as the
normal spaces for indenting, which is asking for trouble. You shouldn't
use the name 'self' when you're not inside a method definition (it's not
an error, but it is sure confusing).
If I take my best guess at some class and method definitions, and paste
this fragment into a method of a class, and fix the indenting to what I
might guess you were planning, it compiles and runs without problems.
But I expected that, since the error is supposed to be in column 78, and
you didn't have that many columns in your posting. Even if I add back
in the two tabs you omitted, and count them as eight characters each,
we're still ten characters short.
Finally the error line displayed is not included in your excerpt. Since
the error message used ellipses in its quoting of the line, we can't see
it all. But if I had to guess, I'd say it was a case of mismatched
quotation marks. Or two lines combined together (note the two
occurrences of self.response.out.write() )
DaveA
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Re: [Tutor] Reading Data From File
Chris Castillo wrote: Okay I really need help with the program I am writing. I've can't seem to figure out what I need to do and have tried several different methods. I need to read in a text file in python that contains the following: Student Name ( could be unknown amount in file ) Numeric Grade ( could be unknown amount in file also ) Numeric Grade Numeric Grade 0 (zero value to terminate and move on to next student and their grades) I need to print the following to the screen: Student NameNumeric Grade, Numeric Grade, Numeric grade, etc.. - ( then A, B C, D, or F average ) PLEASE HELP ME. I need to put the grades into a list and process each student's grades before processing the next student's grades so that I can print each Name, their grades, and average on the same line ( like above ). Thanks Generally, when I help someone with his homework, I expect him to have put some visible effort into solving the problem. So you've tried several different methods. Post the code from the most likely one of them, with a description of why it isn't doing what you needed, and one of us will probably be able to give you a hint to get past the trouble spot. Don't post generalities, but actual code. The whole thing should be less than a dozen lines. DaveA ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] What kind of number is this
On 7/25/09, Dave Angel wrote: > Emad Nawfal (9E'/ FHAD) wrote: >> Hi Tutors, >> I have a bunch of text files that have many occurrences like the following >> which I believe, given the context, are numbers: >> >> ١٨٧٢ >> >> ٥٧ >> >> ٢٠٠٨ >> >> etc. >> >> So, can somebody please explain what kind of numbers these are, and how I >> can get the original numbers back. The files are in Arabic and were >> downloaded from an Arabic website. >> I'm running python2.6 on Ubuntu 9.04 >> >> > Those are standard html encodings for some Unicode characters. Skipper > has identified one of them as the digit '1' written in Arabic. I > presume the others will also be recognizable to you, since you > apparently know Arabic. The following text should be copied to a flie > with extension .html Then you run that in a browser, to see the > characters. > > DaveA > > > > > > Test Arabic Characters > > > > Table of characters > 1632 - ٠ > 1633 - ١ > 1634 - ٢ > 1635 - ٣ > 1636 - ٤ > 1637 - ٥ > 1638 - ٦ > 1639 - ٧ > 1640 - ٨ > 1641 - ٩ > > > > > Thank you very much Skipper and Dave. Your replies have been very useful. -- لا أعرف مظلوما تواطأ الناس علي هضمه ولا زهدوا في إنصافه كالحقيقة.محمد الغزالي "No victim has ever been more repressed and alienated than the truth" Emad Soliman Nawfal Indiana University, Bloomington ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] import rsvg
Hello, I have searched high and low but for the life of me I am unable to locate this module. >>> import cairo >>> import rsvg Traceback (most recent call last): File "", line 1, in ImportError: No module named rsvg >>> Basically from my previous post I would like to now manipulate the SVG files and export them as PNG. I am following the http://guillaume.segu.in/blog/code/43/svg-to-png/ post. Is there an up to date method of doing this? Dave ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] import rsvg
maybe because you need to install Gnome-Python On Sat, Jul 25, 2009 at 1:36 PM, wrote: > Hello, > I have searched high and low but for the life of me I am unable to locate > this module. > import cairo import rsvg > Traceback (most recent call last): > File "", line 1, in > ImportError: No module named rsvg > > > Basically from my previous post I would like to now manipulate the SVG files > and export them as PNG. I am following the > http://guillaume.segu.in/blog/code/43/svg-to-png/ post. > > Is there an up to date method of doing this? > > Dave > ___ > Tutor maillist - tu...@python.org > http://mail.python.org/mailman/listinfo/tutor > ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Reading Data From File
I concur with wesley and dave re homework. Some questions to consider: do you know how to open a file? do you know how to read a line from an opened file? do you know how to incorporate reading lines in a loop? do you know how to determine whether a character is "numeric"? do you know how to print a line? what is the criteria for determining A, B C, D, or F average? -- Bob Gailer Chapel Hill NC 919-636-4239 ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] how to get blank value
Hi,
I have a file having lines:-
48 ALA H = 8.33 N = 120.77 CA = 55.18 HA = 4.12 C = 181.50
104 ALA H = 7.70 N = 121.21 CA = 54.32 HA = 4.21 C =
85 ALA H = 8.60 N = CA = HA = 4.65 C =
Now i want to make two another file in which i want to put those lines for
which C is missing and another one for which N,CA and C all are missing,
With these commands:-
import re
f = open('chem.txt')
for line in f:
if re.search('C = ',line):
print line
I am getting those lines for which C value is there but how to get those
one for which it doesn't have any value, i did google search but still i
am not getting.
Amrita Kumari
Research Fellow
IISER Mohali
Chandigarh
INDIA
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Re: [Tutor] how to get blank value
wrote
With these commands:-
import re
f = open('chem.txt')
for line in f:
if re.search('C = ',line):
print line
I am getting those lines for which C value is there but how to get those
one for which it doesn't have any value, i did google search but still i
am not getting.
Don;t do a Google search, just read the re documentation,
including the HowTo, looking for how to detect the
end of a line.
Alan G.
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Re: [Tutor] What kind of number is this
"Emad Nawfal (عماد نوفل)" wrote in message news:652641e90907250514m1566287aq75f675fd63360...@mail.gmail.com... On 7/25/09, Dave Angel wrote: Emad Nawfal (9E'/ FHAD) wrote: Hi Tutors, I have a bunch of text files that have many occurrences like the following which I believe, given the context, are numbers: ١٨٧٢ ٥٧ ٢٠٠٨ etc. So, can somebody please explain what kind of numbers these are, and how I can get the original numbers back. The files are in Arabic and were downloaded from an Arabic website. I'm running python2.6 on Ubuntu 9.04 Those are standard html encodings for some Unicode characters. [snip] You might find re.sub() useful to process your text files. It will replace the HTML encodings with the actual Unicode character. import re data = u"١٨٧٢٥٧٢٠٠٨" s = re.sub(r'&#(\d+);',lambda m: unichr(int(m.group(1))),data) s u'\u0661\u0668\u0667\u0662\u0665\u0667\u0662\u0660\u0660\u0668' print s 1872572008 And this can be helpful for identifying Unicode characters: import unicodedata for c in s: ... print unicodedata.name(c) ... ARABIC-INDIC DIGIT ONE ARABIC-INDIC DIGIT EIGHT ARABIC-INDIC DIGIT SEVEN ARABIC-INDIC DIGIT TWO ARABIC-INDIC DIGIT FIVE ARABIC-INDIC DIGIT SEVEN ARABIC-INDIC DIGIT TWO ARABIC-INDIC DIGIT ZERO ARABIC-INDIC DIGIT ZERO ARABIC-INDIC DIGIT EIGHT -Mark ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] sqlite: don't understand a code snippet
Dear tutors,
I am trying to teach myself the way Python's works with databases.
I decided to start with SQLite, and am looking at Summerfield's
'Programming in Python 3'.
I got a code snippet that I don't fully understand (the comments are mine):
def get_and_set_director(db, director):
# try to fetch existing director ID from db
director_id = get_director_id(db, director)
# if director ID was found in db, return ID
if director_id is not None:
return director_id
cursor = db.cursor()
# insert new director record
cursor.execute("INSERT INTO directors (name) VALUES (?)",
(director,))
db.commit()
# retrieve and return new director ID from db
return get_director_id(db, director)
Here is what I think is going on:
The function get_and_set_director() gets the director ID from the db
by calling the function get_director-id() and returns its value.
If the director ID is not in the db then, from outside the
get_and_set_director() function, the ID gets inserted to the db via
the commit() method. Finally, the director ID is returned (from the db)
by once again calling the get_director_id() function.
Question: where does a new the director ID come from?
Thanks for your directions!
David
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Re: [Tutor] Need to be pointed in the right direction for file organisation.
Thank you Alan for the prompt reply, > - Put reusable components into modules. OK: the use of files as "libraries" is quite clear to me and indeed I am already doing that. What is not clear is if I should _only_ put in modules stuff that is reusable, or if there are other widely accepted ways to user files. For example, in the GTK application I am currently developing I have a notebook widget (sort of tabbed windows which are visible only one at a time). I was therefore thinking about separating the classes for each "tabbed window" in different files, under the impression that this would make the program faster / with a smaller memory footprint, as only the needed file will be loaded into memory [In PHP you can reach quite a gain in terms of speed if yo do so]. Would this be considered a proper way to code in python? Another concern of mine was the readability of the source code, and I was wondering indeed if there was a "pythonic style" that was commonly understood as "the right one" [I'm thinking to those kind of guidelines like "put the import directive at the top of the file", but for file organisation] > - Build modules "bottom up" so that depenedencies tend to > go one way, with higher level modules importing lower level ones. I'm not sure I got it completely, does this mean that the file structure should be a hint of how dependency works, with ancestors nested in the subfolders of the children classes or something similar? Anyhow, thanks a lot for having answered so promptly! :) Mac. > > While I am working my way up to a more pythonic and cleaner style in > > the code, one thing that I have very confused ideas about is how I > > should organise my code, in terms of classes and files. > > I don't think there is any definitive answer. > > - Put reusable components into modules. > > - Don't necessarily create a module per class, but rather gather > related classes into a single module. > > - Build modules "bottom up" so that depenedencies tend to > go one way, with higher level modules importing lower level ones. > ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Reading Data From File
grades = []
names = []
gradeTotal = 0
numStudents = 0
inputFile = open("input.txt", "r"
for line in inputFile:
if line.strip().isdigit():
grade = float(line)
if grade != 0.0:
gradeTotal += grade
grade = grades.append(grade)
else:
name = line.strip()
name = names.append(name)
This just loops over the entire file basically and just continually adds
the grades to the grades list and names to the names list. How do I just
process each student's set of grades before moving on to the next one
(since there is a zero terminating value telling the loop that a new
student and his or her grades are about to follow)
By the way I'm not worrying about determining the letter grade average
right now, i'm importing a module I wrote after I figure this part out.
On Jul 25, 2009 8:34am, bob gailer wrote:
I concur with wesley and dave re homework.
Some questions to consider:
do you know how to open a file?
do you know how to read a line from an opened file?
do you know how to incorporate reading lines in a loop?
do you know how to determine whether a character is "numeric"?
do you know how to print a line?
what is the criteria for determining A, BC, D, or F average?
--
Bob Gailer
Chapel Hill NC
919-636-4239
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Re: [Tutor] sqlite: don't understand a code snippet
2009/7/25 David :
> Dear tutors,
>
> I am trying to teach myself the way Python's works with databases.
> I decided to start with SQLite, and am looking at Summerfield's
> 'Programming in Python 3'.
> I got a code snippet that I don't fully understand (the comments are mine):
>
>
> def get_and_set_director(db, director):
> # try to fetch existing director ID from db
> director_id = get_director_id(db, director)
> # if director ID was found in db, return ID
> if director_id is not None:
> return director_id
> cursor = db.cursor()
> # insert new director record
> cursor.execute("INSERT INTO directors (name) VALUES (?)",
> (director,))
> db.commit()
> # retrieve and return new director ID from db
> return get_director_id(db, director)
>
> Here is what I think is going on:
>
> The function get_and_set_director() gets the director ID from the db
> by calling the function get_director-id() and returns its value.
>
> If the director ID is not in the db then, from outside the
> get_and_set_director() function, the ID gets inserted to the db via
> the commit() method. Finally, the director ID is returned (from the db)
> by once again calling the get_director_id() function.
>
> Question: where does a new the director ID come from?
>
> Thanks for your directions!
>
> David
>
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>
It sounds as if the directors table has an AUTO_INCREMENT column,
which will automatically assign itself the next value sequentially
when you insert an entry into the table. i.e. The first inserted
entry gets an ID of 1, the next 2, and so on. This is stored in a
column in the table. The get_director_id(...) function will do
something like the following query:
cursor.execute("SELECT id FROM directors WHERE name == \"%s\"", (name,))
I don't know how well I've explained it, but this is the normal
technique for generating unique ids for rows in a database.
--
Rich "Roadie Rich" Lovely
There are 10 types of people in the world: those who know binary,
those who do not, and those who are off by one.
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Re: [Tutor] Need to be pointed in the right direction for file organisation.
"Mac Ryan" wrote time). I was therefore thinking about separating the classes for each "tabbed window" in different files, under the impression that this would make the program faster / with a smaller memory footprint, as only the needed file will be loaded into memory The gains would be minimal, and its dcertainly not common practice. In fact having more modules loaded might even make performance worse! I'd certainly categorize that as premature optimisation! Another concern of mine was the readability of the source code, and I was wondering indeed if there was a "pythonic style" that was commonly understood as "the right one" Not for file organisation. There is the package concept so if you have a lot of related modules you could create a package structure, but most of Python's organisation guidelines tend to focus on maximising reuse rather than organizing the current project, in my experience at least. - Build modules "bottom up" so that depenedencies tend to go one way, with higher level modules importing lower level ones. I'm not sure I got it completely, does this mean that the file structure should be a hint of how dependency works, No, just that you should try to keep low level functuions etc in separate files and have the higher level, more abstract modules import them. Rather than mixing low level, implementation dependant coded with more abstract - and therefore more portable module code. -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] reading into a text file
Hi I am trying to read a html document into a text file to looks at it for the
purpose of spliting the data. I am not sure I am doing this right. I have my
html
document, my text file and a python script I called convt.py on the desktop in
a
folder. I opened up IDLE (python GUI) opened the folder on my desk top and then
went to run module. I keep getting an error saying "No such file or
directory: 'source.txt'
I am new to python so I really don't know if I am doing this right. Any
suggestions?
#!/usr/bin/python
u=open("source.txt").read()
lines = u.split("")
print lines[1]
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Re: [Tutor] reading into a text file
wrote
Hi I am trying to read a html document into a text file
Hi, welcome to the tutor list.
First thing to point out is that HTML files are just text files with
a particular structure. But so far as reading them in Python
goes they are no different to any other text file.
purpose of spliting the data.
Now this is where it gets interesting, it depends what
exactly you are trying to "split". What do you mean by
the "data"? If its the HTML elements there are specialised
Python tools that will make this a lot easier. But if it is
simply splitting into separate lines, read on...
I am not sure I am doing this right. I have my html
document, my text file and a python script I called
convt.py on the desktop
Its usually a bad idea in Windows to do anythiong on
the Desktop, keep that as a place for putting icons to
launch programs. Put working files into separate project
folders.
in a folder.
I assume this means a folder on your Desktop?
That's slightly better but still leaves problems because the
true path to your folder is:
C:\Documents and Settings\YourName\Desktop\YourFolder
Which Windows tries to hide most of the time!
Personally I'd recommend creating a "Projects" or "Work"
folder at the top level of one of your drives (if you have more than one)
and moving your folder under that. Then the full path becomes
D:\Work\MyFolder
Which is a lot easier to deal with and less likely to run into Windows
"cleverness" issues.
I opened up IDLE (python GUI) opened the folder on my desk top and then
went to run module.
OK, I'm still not 100% clear on what you are doing here but
this is probably a good time to get to know the Windows
command prompt. (Take a look at the box on the Getting Started
topic in my tutorial for a brief intro.) Thats a better way to run your
programs on real data IMHO.
I keep getting an error saying "No such file or directory: 'source.txt'
If you start a command prompt
Start->Run
Type CMD, Hit OK
At the prompt
C:\WINDOWS> or similar
type
python myscript.py
It should now find it.
I am new to python so I really don't know if I am doing this right.
#!/usr/bin/python
u=open("source.txt").read()
lines = u.split("")
print lines[1]
You are splitting by the sequence of .
That is each "line" starts with a paragraph tag followed immediately
by a bold tag, is that really what you want? If so it looks fine.
You could modify your program so that it takes the filename at the
command line, so you can process more than one file:
python myscript foo.html
or
python myscript.py bar.html
for example
HTH,
--
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/
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[Tutor] First code snipet
I'm starting to learn Python as it seems to be adopted by many companies that I've been looking to apply to. I used the book Learning Phython to get the basics of the language and many of the gotcha's. I think I know enough of the basic features of the language to start playing around and can understand most code I've seen so far by looking at some of the posts here. The one worry I have is not coding things the Phython way as I've been a Visual Basic programmer for so long and a C++ programmer before that. So would like to have people look at a simplistic class (shuffles lists of objects wrote it for shuffling cards but with Phython could be used for any "list" type object) I wrote to give me some feedback on the style of it. Any feedback is appreciated. Thanks, Brian import random class shuffler(object): def __init__(self): self.rgen = random.Random() def shuffle(self, inpile1, inpile2): """Function that shuffles two list of items.""" if self.rgen.randint(0,1): #randomly decide which pile is shuffled down first (pile1,pile2)=(inpile1,inpile2) else: (pile1,pile2)=(inpile2,inpile1) pile1c = len(pile1) pile2c = len(pile2) rpile = pile1[0:0] #get blank copy of the passed in object types. Should allow user defined list type objects to work as well while pile1c and pile2c:#while there are still items in both piles execute following logic i = self.rgen.randint(1,4) #to allow for human error get random offset of items to shuffle if i > pile1c: #ensure we don't go out of bounds for the pile i = pile1c for x in range(0,i):#append cards to the output pile and remove from shuffle pile rpile.append(pile1.pop(0)) pile1c -= 1 i = self.rgen.randint(1,4) #to allow for human error get random offset of items to shuffle if i > pile2c: #ensure we don't go out of bounds for the pile i = pile2c for x in range(0,i):#append cards to the output pile and remove from shuffle pile rpile.append(pile2.pop(0)) pile2c -= 1 #check for which pile has left over items if any do if pile1c: rpile.extend(pile1) elif pile2c: rpile.extend(pile2) return rpile def shuffledeck(self, deck): """Function that shuffles a list type object""" i = len(deck) #get length of the deck object to shuffle cut = (i // 2) + self.rgen.choice(range(-4,5)) #find half way point of deck +/- human error factor pile1 = deck[0:cut] pile2 = deck[cut:] return self.shuffle(pile1,pile2) if __name__ == '__main__': myshuffle = shuffler() deck = range(1,53) print deck for i in range(1,5): deck = myshuffle.shuffledeck(deck) print deck ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Reading Data From File
ctc...@gmail.com wrote:
grades = []
names = []
gradeTotal = 0
numStudents = 0
inputFile = open("input.txt", "r"
for line in inputFile:
if line.strip().isdigit():
grade = float(line)
if grade != 0.0:
gradeTotal += grade
grade = grades.append(grade)
else:
name = line.strip()
name = names.append(name)
This just loops over the entire file basically and just continually
adds the grades to the grades list and names to the names list. How do
I just process each student's set of grades before moving on to the
next one (since there is a zero terminating value telling the loop
that a new student and his or her grades are about to follow)
By the way I'm not worrying about determining the letter grade average
right now, i'm importing a module I wrote after I figure this part out.
On Jul 25, 2009 8:34am, bob gailer wrote:
I concur with wesley and dave re homework.
There are syntax errors of at least two kinds here. The first is you're
missing a trailing parenthesis. And the second is you lost all your
indentation when you retyped the code. It'd really be better if you
pasted the actual code instead. Not much of a problem in this case, at
least if I guess the same as you had, but in many cases the indentation
*is* the problem.
Next problem is that you're assuming that list.append() returns
something useful. It doesn't return anything, which is to say it returns
"None." So it's not useful to do:
grade = grades.append(grade)
just leave off the left half of that. And likewise leave off the name=
from the other call to append().
The next problem is that you have two independent lists, but no way to
correlate which elements of one correspond to which elements of the
other. So you have a choice to make. Do you need all the data for
post-processing, or is it enough that you print it out, and discard it
afterwards?
I'll assume that you'd answer that it's enough to just be able to print
it out. In that case, you just need some well placed print statements.
Each time you come to a line with a zero in it, you have enough
information to print out one student's information. And in this case,
you don't need a list of students, just the name of the current one.
Do you expect any numbers to be non-integers? I'd assume so because you
used the float() function instead of int(). But isdigit() is going to
be a problem if there's a decimal in there.
DaveA
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[Tutor] Need to start learning again
I started learning python, but then life got busy... I need some help finding good resources to start learning again. My main need for python at first would be to write small programs to perform system commands. Like moving files around, copying or deleting files, and perhaps some simple interface construction so I can create a window to show the status of the little programs i plan to write. Any help would be appreciated. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Need to start learning again
Check out thenewboston's video tutorials at Youtube: http://www.youtube.com/view_play_list?p=EA1FEF17E1E5C0DA They're fairly recent and they definitely got me started with learning the syntax. After you're through with those, he also has a series on wxPython. A couple ebooks you'd be interested in would be Dive into Python or A Byte of Python, both very thorough and descriptive, the latter being a bit easier to newer programmers. A great book might consider purchasing would be Wesley Chun's Core Python Programming. This is only a slice of the cake though, try Googling around for more resources. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] First code snipet
Some things: 1) It's Python, not Phython. 2) Slightly shorter solution to your problem: import random input = range(53) random.shuffle(input) print input 3) The important part here is that reimplementing something that is in the standard library does not make sense usually. 4) A more sensible implementation of shuffle comes directly out of random.py: def shuffle(self, x, random=None, int=int): """x, random=random.random -> shuffle list x in place; return None. Optional arg random is a 0-argument function returning a random float in [0.0, 1.0); by default, the standard random.random. """ if random is None: random = self.random for i in reversed(xrange(1, len(x))): # pick an element in x[:i+1] with which to exchange x[i] j = int(random() * (i+1)) x[i], x[j] = x[j], x[i] Notice that it is not exactly optimal, one could easily replace the reversed(xrange()) expression with a 3 parameter version of xrange: for i in xrange(len(x) - 1, 0, -1): Andreas Am Samstag, den 25.07.2009, 17:15 -0700 schrieb Darth Kaboda: > I'm starting to learn Python as it seems to be adopted by many > companies that I've been looking to apply to. I used the book Learning > Phython to get the basics of the language and many of the gotcha's. I > think I know enough of the basic features of the language to start > playing around and can understand most code I've seen so far by > looking at some of the posts here. > > The one worry I have is not coding things the Phython way as I've been > a Visual Basic programmer for so long and a C++ programmer before > that. So would like to have people look at a simplistic class > (shuffles lists of objects wrote it for shuffling cards but > with Phython could be used for any "list" type object) I wrote to give > me some feedback on the style of it. > > Any feedback is appreciated. > > Thanks, > Brian > ___ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor signature.asc Description: Dies ist ein digital signierter Nachrichtenteil ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] First code snipet
> Subject: Re: [Tutor] First code snipet > From: andr...@kostyrka.org > To: darthkab...@msn.com > CC: tutor@python.org > Date: Sun, 26 Jul 2009 03:02:27 +0200 > > Some things: > > 1) It's Python, not Phython. > 2) Slightly shorter solution to your problem: > > import random > > input = range(53) > random.shuffle(input) > print input > > 3) The important part here is that reimplementing something that is in > the standard library does not make sense usually. > > 4) A more sensible implementation of shuffle comes directly out of > random.py: > > def shuffle(self, x, random=None, int=int): > """x, random=random.random -> shuffle list x in place; return > None. > > Optional arg random is a 0-argument function returning a random > float in [0.0, 1.0); by default, the standard random.random. > """ > > if random is None: > random = self.random > for i in reversed(xrange(1, len(x))): > # pick an element in x[:i+1] with which to exchange x[i] > j = int(random() * (i+1)) > x[i], x[j] = x[j], x[i] > > Notice that it is not exactly optimal, one could easily replace the > reversed(xrange()) expression with a 3 parameter version of xrange: > for i in xrange(len(x) - 1, 0, -1): > > Andreas > > > > Am Samstag, den 25.07.2009, 17:15 -0700 schrieb Darth Kaboda: > > I'm starting to learn Python as it seems to be adopted by many > > companies that I've been looking to apply to. I used the book Learning > > Phython to get the basics of the language and many of the gotcha's. I > > think I know enough of the basic features of the language to start > > playing around and can understand most code I've seen so far by > > looking at some of the posts here. > > > > The one worry I have is not coding things the Phython way as I've been > > a Visual Basic programmer for so long and a C++ programmer before > > that. So would like to have people look at a simplistic class > > (shuffles lists of objects wrote it for shuffling cards but > > with Phython could be used for any "list" type object) I wrote to give > > me some feedback on the style of it. > > > > Any feedback is appreciated. > > > > Thanks, > > Brian > > ___ > > Tutor maillist - Tutor@python.org > > http://mail.python.org/mailman/listinfo/tutor Thanks for the correction not sure why I typed it that way after typing it correctly in the first sentence, must have wondered off somewhere in my mind I guess. Oops I guess I should have also mentioned what I was trying to accomplish with this class. I wanted to mimic how a deck of cards get's shuffled in the real world. i.e. split the deck and shuffle the two halves together. Brian ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Need to start learning again
On Sat, Jul 25, 2009 at 6:24 PM, Fred @ Mac wrote: > I started learning python, but then life got busy... I need some help > finding good resources to start learning again. > I learned everything I know from Google ;) or at least sources provided by Google. I'd also recommend Python for System Administrators by Noah Gift and Jeremy Jones. If it's available at your local public library, I'd check it out (and well worth the $15 price used). > > My main need for python at first would be to write small programs to > perform system commands. Like moving files around, copying or deleting > files, and perhaps some simple interface construction so I can create a > window to show the status of the little programs i plan to write. Python for Sys admins covers all of the above. If you want a very simple interface, I'd go with Tkinter. It's a lot easier to use than some of the bigger GUIs, like GTK, but it also sacrifices a lot of features to go with that simplicity. A couple of folks on this mailing list have python tutorials that are certainly worth a read. HTH, Wayne ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] First code snipet
On Sat, Jul 25, 2009 at 7:15 PM, Darth Kaboda wrote: > I'm starting to learn Python as it seems to be adopted by many companies > that I've been looking to apply to. I used the book Learning Phython to get > the basics of the language and many of the gotcha's. I think I know enough > of the basic features of the language to start playing around and can > understand most code I've seen so far by looking at some of the posts here. > > The one worry I have is not coding things the Phython way as I've been a > Visual Basic programmer for so long and a C++ programmer before that. So > would like to have people look at a simplistic class (shuffles lists of > objects wrote it for shuffling cards but with Phython could be used for any > "list" type object) I wrote to give me some feedback on the style of it. > > Any feedback is appreciated. > There's a spot in your code that could be turned into a function. I'm not sure what you'd call it, but where you "lay down" 1-4 cards. Since you're doing the same thing for each stack, you may as well turn it into a function and just call it for each stack. Pretty cool idea for something to do, though. -Wayne ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Need to start learning again
> From: fredp...@mac.com > To: tutor@python.org > Date: Sat, 25 Jul 2009 16:24:13 -0700 > Subject: [Tutor] Need to start learning again > > I started learning python, but then life got busy... I need some help > finding good resources to start learning again. > > My main need for python at first would be to write small programs to > perform system commands. Like moving files around, copying or > deleting files, and perhaps some simple interface construction so I > can create a window to show the status of the little programs i plan > to write. > > Any help would be appreciated. For file manipulation, take a look at this: http://effbot.org/librarybook/os.htm And yes, Tkinter probably would make things easier for a simple GUI. _ Windows Live™ Hotmail®: Celebrate the moment with your favorite sports pics. Check it out. http://www.windowslive.com/Online/Hotmail/Campaign/QuickAdd?ocid=TXT_TAGLM_WL_QA_HM_sports_photos_072009&cat=sports___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
