[Tutor] What has Editor X got that PyWin32 hasn't?
On Wed, 2008-08-13 at 16:59 +0200, [EMAIL PROTECTED] wrote: Message: 5 Date: Wed, 13 Aug 2008 09:58:52 -0500 From: W W [EMAIL PROTECTED] Subject: Re: [Tutor] What has Editor X got that PyWin32 hasn't? To: Dick Moores [EMAIL PROTECTED] Cc: Python Tutor List tutor@python.org Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=iso-8859-1 On Wed, Aug 13, 2008 at 9:42 AM, Dick Moores [EMAIL PROTECTED] wrote: Since downloading vim 7.2 yesterday, I've had some trouble distinguishing vim and gvim (both were included). Can you help me out? gvim is GUI-vim, I think. Isn't that what I want to learn? Is gvim a cut-down version of vim, but enables you to use your mouse ( :set mouse=a)? You can subscribe to vim mailing list by sending a blank email to [EMAIL PROTECTED] It is very friendly even for beginners, Bram Moolenaar, also gets to answer your questions sometimes! ;) As far as I know/have used, gvim is simply vim, but for lack of a better comparison, in its own terminal. The same thing you would have if you were to type vim at the command line. Honestly, the only thing I know how to do with the mouse in gvim is paste (middle click in linux). Or access the menus. That's one of the main reasons I /use/ vim - so I don't have to touch the mouse :) As far as any keyboard commands that I use, I've not seen any difference between vim, vi, and gvim. The main difference is syntax highlighting. -Wayne ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 53, Issue 110
Message: 5
Date: Thu, 31 Jul 2008 09:07:22 -0400
From: S Python [EMAIL PROTECTED]
Subject: [Tutor] Reading List from File
To: tutor@python.org
Message-ID:
[EMAIL PROTECTED]
Content-Type: text/plain; charset=iso-8859-1
Hi Everyone,
I am trying to read a comma-delimitted list (aaa,bbb,ccc) from a
text
file and assign those values to a list, x, such that:
x = [aaa, bbb, ccc]
The code that I have come up with looks like this:
x = []
f = open(r'c:\test.txt', 'r')
x.extend(f.readlines())
x
['aaa,bbb,ccc']
If you look closely, there is an extra pair of single quotes (') that
encapsulates the string. Therefore, len(x) returns 1, instead of 3.
Is
there a function to separate this list out? I hope my question
makes
sense.
I think you are better off using the csv module. If you have a comma
separated file you could...
import csv
reader = csv.reader(open(some.csv, rb))
for row in reader:
print row
I yanked this straight out of the Python Reference Library :)
Thanks in advance.
Samir
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Re: [Tutor] Tutor Digest, Vol 53, Issue 99
On Tue, 2008-07-29 at 01:12 +0200, [EMAIL PROTECTED] wrote:
Message: 3
Date: Mon, 28 Jul 2008 13:26:13 -0500
From: Daniel Sarmiento [EMAIL PROTECTED]
Subject: Re: [Tutor] Memory error - how to manage large data sets?
To: tutor@python.org
Message-ID:
[EMAIL PROTECTED]
Content-Type: text/plain; charset=ISO-8859-1
Hi
I tried to run your code and checked (with top) the memory ussage and
it uses more than 2 Gb of memory.
I tried to modify the code a little bit to use less memory and came up
with this:
fib = {0:0,1:1}
even = []
def fibonacci(x,y):
return x+y
for j in xrange (2,100):
i = fib[j-1] + fib[j-2]
if i % 2 == 0:
even.append(i)
fib = {j-1:fib[j-1], j:i}
total = reduce(fibonacci,even)
print total
First, I replaced range with xrange.
I figured that you only need the last two values in the fibonnaci
series to calculate the next value, so I replaced the fib list with a
dictionary to only store the last two values instead of the whole
series.
It looks like the progam still hangs and I did not notice any memory
imrovements when running it with 1 000 000
Am I wrong thinking that the modifications I made help use less
memory?
I have realised that when you need to work with large numbers, lists are
slow and tend to gobble up bytes. Another thing try to be as simple as
possible :). This is how I would approach the problem, without using
lists. It produces the result instantly, even for large numbers like a
100, 000, 000.
def fibonacci()
a = 0
b = 1
evenTotal = 0
while a 1:
a,b = b,a+b
if a%2 == 0:
evenTotal += a
print evenTotal
Does this help?
Kinuthia...
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Re: [Tutor] Memroy Error - how to manage large data sets?
On Tue, 2008-07-29 at 12:00 +0200, [EMAIL PROTECTED] wrote: Message: 2 Date: Tue, 29 Jul 2008 08:44:40 +0100 From: Alan Gauld [EMAIL PROTECTED] Subject: Re: [Tutor] Tutor Digest, Vol 53, Issue 99 To: tutor@python.org Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; format=flowed; charset=iso-8859-1; reply-type=original kinuthiA muchanE [EMAIL PROTECTED] wrote I have realised that when you need to work with large numbers, lists are slow and tend to gobble up bytes. The lists are not particularly slow (obviously if you want to traverse them they take longer for more members) and they don't take up much more memory that the sum of the sizes of whats in them. The problem here is that the data items themselves are huge. Around 20K per item. Thus a million times 20K is 20G! This is how I would approach the problem, without using lists. Yep, we all seem to be pretty much in agreement :-) It produces the result instantly, even for large numbers like a 100, 000, 000. Umm, not instantly on my PC... 1 million took 5 minutes, I've no idea how long 100 million would take! I think the question is to calculate the sum of all even numbers in the Fibonacci series which do not exceed a million, not the millionth term. Number 25 on Project Euler which asks for first term in the Fibonacci series to contain 1000 digits, is the term-wise question ;) def fibonacci() a = 0 b = 1 evenTotal = 0 while a 1: a,b = b,a+b if a%2 == 0: evenTotal += a print evenTotal Alan G ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Newbie
On Fri, 2008-07-25 at 03:47 +0200, [EMAIL PROTECTED] wrote: Message: 9 Date: Thu, 24 Jul 2008 18:47:32 -0700 (PDT) From: Sam Last Name [EMAIL PROTECTED] Subject: [Tutor] Newbie To: tutor@python.org Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=us-ascii mmmkay its me again Iv'e been learning alot and have found so much joy in making programs that solve equations using the input function. I need Help on this though. Im trying to make a program where it solves the quadratic formula when you put in the variables. Here wats i got so far. :) and also, is there a function for square root? a = input(What is the variable a?) b = input(What is the variable b?) c = input(What is the variable c?) # this is where i need help :( print -b + /sqrt (b*b - 4*a*c)/(2*a) # this of course doesn't work i believe because i don't have the square root function and don know how to make one import math print math.sqrt(6) 2.44948974278 print math.sqrt(8) 2.82842712475 math is a module which contains most of the mathematical functions that you need most of the time. Here we used just one of them, sqrt, to find the square root of an integer. The Python Library Reference lists all of them and their usage. Does this help? Kinuthia... Feedback appreciated :) ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 53, Issue 18
On Sat, 2008-07-05 at 20:23 +0200, [EMAIL PROTECTED] wrote: Message: 7 Date: Sat, 05 Jul 2008 12:23:36 -0600 From: Nathan Farrar [EMAIL PROTECTED] Subject: [Tutor] Exploring the Standard Library To: Python Tutor tutor@python.org Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=us-ascii I'd like to spend some time exploring the standard library. I'm running python on Ubuntu. How would I find the location of the modules (find / -name os.py does not yield results)? In Ubuntu, you can find all the documentation in the /usr/share/doc directory. Therefore, for python you will find it in /usr/share/doc/python. Furthermore, to find the location of some documentation, in the terminal enter dpkg -L package-name, in your case, just type dpkg -L python and you will be rewarded with paths for all python related documentation. Does this help? Kinuthia... Thanks! Nathan ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 52, Issue 87
On Sun, 2008-06-29 at 10:20 +0200, [EMAIL PROTECTED] wrote: Message: 1 Date: Sat, 28 Jun 2008 21:53:44 -0400 From: Kirk Z Bailey [EMAIL PROTECTED] Subject: [Tutor] arrays in python To: tutor@python.org Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=ISO-8859-1; format=flowed Just wondering, if I can find a way to do a 2 dimensional array in python. 1 dimension would be a list it would seem; for 2, I could use a list of lists? Strange how I can't think of ever needing one since I discovered snake charming, but so many languages do foo dimensional arrays, it would seem like there ought to be a way to do it in python. -- from numpy import * # import the necessary module arry = array((1,2,3,4)) # create a rank-one array print arry [1 2 3 4] print arry.shape (4,) # this means it is a rank 1 array with a length of 4 (the trailing comma means it is a tuple) To get to the first element in the array: print arry[0] 1 To get to the last element: print arry[-1] 4 arry2 = array(([5,6,7,8],[9,10,11,12])) # create a a rank-two array, two-dimensional, if wish print arry2 [[ 5 6 7 8] [ 9 10 11 12]] print arry2.shape # (2, 4) # this means that it is a rank 2 (ie 2-dimensional) array, with each axis having a length of 4 To get to the first element in the first axis: print arry2[0,0] 5 To get to the last element in the second axis: print arry2[1,-1] 12 You can slice it, reshape it, literally you can contort in way you want! Does this help? Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Problem Euler 26
Hi, I am trying to solve Problem Number 26 (http://projecteuler.net/index.php?section=problemsid=26) on project Euler but apparently the answer I am submitting is wrong. Here is the problem: A unit fraction contains 1 in the numerator. The decimal representation of the unit fractions with denominators 2 to 10 are given: 1/2 = 0.5 1/3 = 0.(3) 1/4 = 0.25 1/5 = 0.2 1/6 = 0.1(6) 1/7 = 0.(142857) 1/8 = 0.125 1/9 = 0.(1) 1/10 = 0.1 Where 0.1(6) means 0.16..., and has a 1-digit recurring cycle. It can be seen that 1/7 has a 6-digit recurring cycle. Find the value of d 1000 for which 1/d contains the longest recurring cycle in its decimal fraction part. I am giving the answer 38, because 1/38 = 0.0263157894. It seems I have misunderstood the question or I cant solve it! Here is the code that I came up with: def aux(num): import re pattern = re.compile(r^0?1?2?3?4?5?6?7?8?9?$) frac =%.9f%(1.0/num) fracSlice = frac[2:]# get the decimal fractional part, ie remove '0.' fracList = list(fracSlice) #convert string to a list fracList.sort() # I need to sort , because I will be searching by increasing order testFrac = .join(fracList) # convert list back to a string, phew! if re.match(pattern,testFrac): # if the pattern matches, the number is our candidate print (num,fracSlice) for b in xrange(1,1000): aux(b) Er... er, that does not exactly work as expected but it narrows the search to only 3 candidates because of the inclusion of the zero: (28, '035714286') (38, '026315789') (81, '012345679') For 28, the digit, in the fractional part, after 8 is 5, so 5 is repeated and as for, 81 the next digit after 7 is 0, so again 0 occurs twice. But for 38, the next digit after 9 is 4, and because it has NOT occurred before, I assume 38 is the correct answer... and I am wrong! I suspect I have completely misunderstood the question. Any ideas? Thanks! Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Invoking Python
On Thu, 2008-06-26 at 12:00 +0200, [EMAIL PROTECTED] wrote: Or more commonly add a first line like: #! /path/to/python/executable Then you can simply make the file executable and run it by typing its name $ threeplusfour.py On my computer, running Linux Ubuntu, I always have to type ./threePlusFour.py to get it to run. Otherwise I get a not found command. or double clicking it in your favourite file manager GUI tool. See the topic Add a Little style in my tutorial, in the box Note for Unix users for more details. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 52, Issue 69
On Wed, 2008-06-25 at 01:49 +0200, [EMAIL PROTECTED] wrote: ... or you could start you fire up a text editor (something like Notepad in Windows, or nano in Linux and type 3+4(without the quotes!), Actually it would need to be print 3+4 otherwise Python would silently evaluate the expression but not display the result. Oh my, I was in the middle of something, something like http://projecteuler.net/index.php?section=problemsid=74 One of the indefatigable contributors to this mailing list, Alan Gauld (where do you get the time?), With increasing difficulty! :-) I can understand that. Check it out at http://www.freenetpages.co.uk/hp/alan.gauld (correct?) Correct, thanks for the plug! Sadly it will need to move soon since Freenet have announced that they will soon be decommissioning their free web site(*). I'm trying to decide whether to go to another free site or spend the money for a proper hosted site with dedicated domain name etc... Here (in Kenya) the cheapest unlimited internet access option costs you around 9600 Kenya Shillings, about $146 a month! I am already stumped! (*) They have already blocked ftp so I can't post updates anymore :-( Dommage, dommage... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Invoking Python
On Tue, 2008-06-24 at 11:11 -0700, Danny Laya wrote: ... or you could start you fire up a text editor (something like Notepad in Windows, or nano in Linux and type 3+4(without the quotes!), hmmm..., and save the file as anything you want, lets say for now you save the file as threePlusFour. Every time you invoke the python interpreter (do you know how to do that?) with threePlusFour, you will get the value seven! Well HE..HE i don't know. Let say I write the threePlusFour file in /home/danny/threePlusFour.py How I can invoke that file ??? From the forward slashes in the file path I assume you are using a Linux based OS, Ubuntu perhaps? Well, to use python you need to to start the terminal or the shell. In Ubuntu, go to Main Menu == Accessories and click on Terminal, you will now have a new window open with something like this --- [EMAIL PROTECTED]:~$ . Enter the name python followed by the name of your file. In this case you should enter python /home/danny/threePlusFour.py(without the quotes!). If you want to enter into the Python interactive prompt, simply type python and you should be rewarded with something like: Python 2.5.1 (r251:54863, Oct 5 2007, 13:36:32) [GCC 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2)] on linux2 Type help, copyright, credits or license for more information. The there means python is waiting for you to enter commands. Try 3+4, or 4/3 Does this help? Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 52, Issue 66
On Tue, 2008-06-24 at 15:26 +0200, [EMAIL PROTECTED] wrote: Message: 5 Date: Tue, 24 Jun 2008 05:47:29 -0700 (PDT) From: Danny Laya [EMAIL PROTECTED] Subject: [Tutor] fibonacci.py task ??? To: tutor@python.org Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=iso-8859-1 Hi all, can you explain me what this code mean : Fibonacci.py # This program calculates the Fibonacci sequence a = 0 b = 1 count = 0 max_count = 20 while count max_count: count = count + 1 # we need to keep track of a since we change it old_a = a old_b = b a = old_b b = old_a + old_b # Notice that the , at the end of a print statement keeps it # from switching to a new line print old_a, Output: 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 Do you understand it ??? Can you explain meahhh you know i'm a newbie so please explain it with a simple expalanation. And I got many tutorial with title *.py(e.g: Fibonacci.py and Password.py), can you explain me what *.py mean? Thank's for helping me. If you have an algorithm to calculate the sum of exactly two(!) numbers you could do it in the Python prompt by: 3+4 7 ... or you could start you fire up a text editor (something like Notepad in Windows, or nano in Linux and type 3+4(without the quotes!), hmmm..., and save the file as anything you want, lets say for now you save the file as threePlusFour. Every time you invoke the python interpreter (do you know how to do that?) with threePlusFour, you will get the value seven! Because there are many programming languages, such as C, java, perl, ruby, haskell(!), you might want to be more specific as to what programming language you save saved your code in. .c for C, .rb for Ruby, .java for java and, of course .py for python. ... or you could define a function... One of the indefatigable contributors to this mailing list, Alan Gauld (where do you get the time?), has an excellent tutorial for beginners. Check it out at http://www.freenetpages.co.uk/hp/alan.gauld (correct?) Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] RegEx to search for the '$' symbol
--
Message: 4
Date: Wed, 11 Jun 2008 10:35:30 +0100 (GMT+01:00)
From: [EMAIL PROTECTED] [EMAIL PROTECTED]
Subject: [Tutor] RegEx to search for the '$' symbol
To: tutor@python.org
Message-ID: [EMAIL PROTECTED]
Content-Type: text/plain;charset=UTF-8
Hi,
Silly question but how do you use python's re module to find
dictionary items that contain the '$' symbol.
Hi,
I no expert but here is my dime's worth...
import re
d = {'k':'$',1:'2','p':'$','j':'$dollar','l': 'dol$lar'}
for i in d.values():
... re.findall(r'.*\$.*',i)
...
[]
['$']
['$dollar']
['dol$lar']
[]
NB:
Empty matches are included in the result unless they touch the beginning of
another match.
Kinuthia...
Thanks
David
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Re: [Tutor] Tutor Digest, Vol 51, Issue 51
[EMAIL PROTECTED] wrote:
Send Tutor mailing list submissions to
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than Re: Contents of Tutor digest...
Today's Topics:
1. Re: Equivalent 'case' statement (Alan Gauld)
2. Re: Equivalent 'case' statement (inhahe)
3. Reading only a few specific lines of a file (Jason Conner)
4. Re: Reading only a few specific lines of a file (John Fouhy)
5. Re: String Replacement question (Faheem)
--
Message: 1
Date: Fri, 23 May 2008 00:25:23 +0100
From: Alan Gauld [EMAIL PROTECTED]
Subject: Re: [Tutor] Equivalent 'case' statement
To: tutor@python.org
Message-ID: [EMAIL PROTECTED]
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
reply-type=original
Dinesh B Vadhia [EMAIL PROTECTED] wrote
Is there an equivalent to the C/C++ 'case' (or 'switch') statement
in Python?
No, just if/elif
However you can often achieve similar results with a dictionary:
def func1(v): return v
def func2(v): return v*2
switch = { 'val1': func1, # use a function for each value
'val2': func2,
'val3': lambda v: this is three! } # or use
lambda if preferred
val = raw_input(Value? (val1,val2,val3))
Something small here. This
print switch.[val](val)
should be: print switch[val](val)
### which is equivalent to:
if val == 'val1': print func1(val)
elif val == 'val2': print func2(val)
elif val == 'val3': print this is three
HTH,
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Re: [Tutor] Equivalent 'case' Statement
Hi,
I messed in earlier message, my apologies.
Message: 1
Date: Fri, 23 May 2008 00:25:23 +0100
From: Alan Gauld [EMAIL PROTECTED]
Subject: Re: [Tutor] Equivalent 'case' statement
To: tutor@python.org
Message-ID: [EMAIL PROTECTED]
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
reply-type=original
Dinesh B Vadhia [EMAIL PROTECTED] wrote
Is there an equivalent to the C/C++ 'case' (or 'switch') statement
in Python?
No, just if/elif
However you can often achieve similar results with a dictionary:
def func1(v): return v
def func2(v): return v*2
switch = { 'val1': func1, # use a function for each value
'val2': func2,
'val3': lambda v: this is three! } # or use
lambda if preferred
val = raw_input(Value? (val1,val2,val3))
This:
print switch.[val](val)
should be: print switch[val](val)
### which is equivalent to:
if val == 'val1': print func1(val)
elif val == 'val2': print func2(val)
elif val == 'val3': print this is three
HTH,
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Re: [Tutor] String Replacement Question
Moishy Gluck wrote: %s %st*3 'String String String ' ^ If you look closely at the end of the string there is an extra space. .join((st, )*3) 'String String String' ^ No extra space. Ah...Okay! On Wed, May 21, 2008 at 9:42 AM, Kinuthia Muchane [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: st = String print %s %st*3 String String String Does this help? Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Else Clause In A Loop
Hi, I learnt that a loop can have an else clause. And that this clause executes when the loop TERMINATES. In a while loop when the condition becomes false, and in a for loop when a sequence is exhausted. When I write the following code it seems to work: for n in [1,2,3,4,5]: print 'we are in the loop',n else: print 'we are now EXITING the loop',n which results in: we are in the loop 1 we are in the loop 2 we are in the loop 3 we are in the loop 4 we are in the loop 5 we are now EXITING the loop 5 Or: n = 1 while n = 5: print 'we are in the loop',n n += 1 else: print 'we are now EXITING the loop',n ...which gives: we are in the loop 1 we are in the loop 2 we are in the loop 3 we are in the loop 4 we are in the loop 5 we are now EXITING the loop 6 (it spills over here!) This has served to confuse me more. Would someone please kindly explain how all this fits into the code below which searches (and finds!) for prime numbers... def prime(): number = int(raw_input(Enter a number :)) for i in range(2,number): for j in range(2,i): if i%j == 0: break else: print is a prime number, i prime() ...especially in the instance when number is 2 in the first for statement, for then we will have for j range(2,2)! Or what is going on?? Thanks, Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Else Clause In A Loop
On Mon, 2008-05-12 at 14:08 -0400, Simón A. Ruiz wrote: I'll try my hand at this: The outside for loop is looking through every number up to the variable number. No quarrel here. For each of those numbers, it checks to see if any number between 2 and i is divisible into i. If it finds anything, we know it's not a prime, and so it breaks out of that second loop without completing it, which means the else block isn't executed. This is where I am getting lost. When the variable 'number' is 3, it means that in that instance the inner 'for' statement will be 'for j in range(2,3)', hmmm which means that we will be dividing each element by 2 in the first 'for' statement and checking whether it is true , no? But 2%2 is zero, so, in my warped logic, the inner 'for' loop should break and the else clause will not execute! If it can't find anything that i is divisible by, then that inside for loop finishes without breaking, we know that i is a prime number, and the else clause is executed. This is where it gets even more interesting for me. Wont 'i' in one instance be 8, so at that particular moment there will be a 7 in the inner 'for' loop which will be divisible by one of our 'prime' numbers ie 7?! I know I am wrong but for some reason I cannot see the light! :-) range(2,2) is is an empty list, so the loops ends uneventfully without doing anything and the else clause is executed. I'm not an expert, and this seems to me to be what's happening there. Simón All the same, thanks... kinuthia muchane wrote: Hi, I learnt that a loop can have an else clause. And that this clause executes when the loop TERMINATES. In a while loop when the condition becomes false, and in a for loop when a sequence is exhausted. When I write the following code it seems to work: for n in [1,2,3,4,5]: print 'we are in the loop',n else: print 'we are now EXITING the loop',n which results in: we are in the loop 1 we are in the loop 2 we are in the loop 3 we are in the loop 4 we are in the loop 5 we are now EXITING the loop 5 Or: n = 1 while n = 5: print 'we are in the loop',n n += 1 else: print 'we are now EXITING the loop',n ...which gives: we are in the loop 1 we are in the loop 2 we are in the loop 3 we are in the loop 4 we are in the loop 5 we are now EXITING the loop 6 (it spills over here!) This has served to confuse me more. Would someone please kindly explain how all this fits into the code below which searches (and finds!) for prime numbers... def prime(): number = int(raw_input(Enter a number :)) for i in range(2,number): for j in range(2,i): if i%j == 0: break else: print i, is a prime number prime() ...especially in the instance when number is 2 in the first for statement, for then we will have for j in range(2,2)! Or what is going on?? Thanks, Kinuthia... ___ 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] Project Euler Problem 6
Hi, I am trying to solve problem 6 on the Project Euler, but when I submit my answer, I am told that it is wrong. Here is the problem: The sum of the squares of the first ten natural numbers is, 1² + 2² + ... + 10² = 385 The square of the sum of the first ten natural numbers is, (1 + 2 + ... + 10)² = 55² = 3025 Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025 − 385 = 2640. Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum. And here is my code: def aux(): return sum([k*k for k in range(1,111)])# sum of the squares of the first one hundred numbers def aux1(): inter = sum([k for k in range(1,111))# square of the sum of the first one hundred numbers return inter**2 def aux2(): return aux1() - aux()# the difference of the two sums print aux2() ...which gives a result of 36821290. It worked fine with the example they have given but not with the hundred one... What am I missing? Thanks! Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Euler Problem 6
Hi, I think I need to be more careful in the future. This line return sum([k*k for k in range(1,111)]) should be: return sum([k*k for k in range(1,101)]). ... and this one sum([k for k in range(1,101)) also changes to: sum([k for k in range(1,101)) Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Computing factorial...
Hi,
I wanted to calculate the factorial of a given number without using
recursion. I came up with the following code, although it is not very
elegant it works.
def factorial(*args):
product = args[0]
for item in args[1:]:
product *= item
return product
number = int(raw_input('Enter value of number to compute factorial '))
seq = range(1,number + 1)
if number = 0:
print -1
else:
print factorial(*seq)
When I change that code a bit to (In fact, this is what I started with,
it almost drove me crazy trying to figure out what was wrong!) :
def factorial(*args):
temp = args[0]
for item in args[1:]:
product = temp * item
return product
number = int(raw_input('Enter value of number to compute factorial '))
seq = range(1,number + 1)
if number = 0:
print -1
else:
print factorial(*seq)
... it just echoes back the number you were prompted to enter.
My confusion is, aren't the variables 'temp' and 'product' storing the
same value ie args[0]. So why would they return different values, the
one with temp giving a wrong answer?
Thanks!
Kinuthia...
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Re: [Tutor] Executing from Python prompt
On Sat, 2008-04-19 at 16:06 -0400, bob gailer wrote: kinuthia muchane wrote: Hi, I do not know what I am doing wrong. When I run the following code from the Python prompt it executes without a murmur. But when I save it as a .py file and try to execute it from the shell, it just returns the prompt...actually it is all scripts that return a value which are behaving in this manner. def factorial(n): if n = 1: return 1 else: return n * factorial(n-1) factorial(some number here) print factorial(some number here) When you enter an expression at the interactive prompt you see the value. Not true when you run a program. Expression values must be printed. So you are doing nothing wrong. Thanks, Bob, it worked the first time. It was staring me in the face the whole time! Thanks once again. Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 50, Issue 63
kinuthia muchane [EMAIL PROTECTED] wrote I do not know what I am doing wrong. When I run the following code from the Python prompt it executes without a murmur. But when I save it as a .py file and try to execute it from the shell, it just returns the prompt...actually it is all scripts that return a value which are behaving in this manner. The prompt evaluates expressions and prionts the value. The interpreter on the other hand does not automatically print values you ghave to explicitly tell it to print using the print statement. So in your case just add the print command in front of the function call and all will be well. factorial(some number here) print factorial(n) HTH, -- Alan Gauld Thanks, that worked. Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Executing from Python prompt
Hi, I do not know what I am doing wrong. When I run the following code from the Python prompt it executes without a murmur. But when I save it as a .py file and try to execute it from the shell, it just returns the prompt...actually it is all scripts that return a value which are behaving in this manner. def factorial(n): if n = 1: return 1 else: return n * factorial(n-1) factorial(some number here) The same happens when I use IDLE. Thanks! Kinuthia... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 50, Issue 56
-- Message: 3 Date: Thu, 17 Apr 2008 10:58:00 -0700 From: Dick Moores [EMAIL PROTECTED] Subject: Re: [Tutor] python assignments To: Python Tutor List tutor@python.org Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=us-ascii; format=flowed At 04:42 AM 4/17/2008, you wrote: Dear friends, I covered few introductory books on python. B4 going for an advanced book, i want to take up small, small assignments and try to solve with python. Can someone please suggest me any url where i can have assignments and solutions. http://projecteuler.net/index.php?section=problems Hi, this link is not loading. Dick Moores ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 50, Issue 43
Message: 1
Date: Mon, 14 Apr 2008 01:31:41 -0700
From: Dinesh B Vadhia [EMAIL PROTECTED]
Subject: [Tutor] encode unicode strings from pysqlite
To: tutor@python.org
Message-ID: [EMAIL PROTECTED]
Content-Type: text/plain; charset=iso-8859-1
Here is a program that SELECT's from a pysqlite database table and encode's
the returned unicode strings:
import sys
import os
import sqlite3
con = sqlite3.connect(testDB.db)
cur = con.cursor()
a = u'99 Cycling Swords'
b = a.encode('utf-8')
print b
q = '%wor%'
limit = 25
query = SELECT fieldB FROM testDB WHERE fieldB LIKE '%s' LIMIT '%s' %(q,
limit)
for row in cur.execute(query):
r = str(row)
print r.encode('utf-8')
Why not change this to:
for row in cur.execute(query):
for item in row:
print item.encode('utf-8')
which will return a string ?
Kinuthia.
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