🌐 Mailman 3 May 2000 - Tutor - python.org

Windons Task tray
by rhicks＠rma.edu July 4, 2001

July 4, 2001

Is it possible to minimize a python program to the task tray area of the taskbar in Windows95/98? Bob pop3.rma.edu

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remove me
by theecoop June 1, 2000

June 1, 2000

remove me

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Re: [Tutor] printing variable name and value?
by Emile van Sebille June 1, 2000

June 1, 2000

Just be careful about adding entries. It's not guaranteed to work right. >From the docs: locals () Return a dictionary representing the current local symbol table. Warning: the contents of this dictionary should not be modified; changes may not affect the values of local variables used by the interpreter. Even-though-it-may-look-like-it-ly y'rs, Emile van Sebille emile(a)fenx.com ------------------- ----- Original Message ----- From: Borgulya Gabor <borgulya(a)pons.sote.hu> To: Emile van Sebille <emile(a)fenx.com> Sent: Monday, May 29, 2000 10:12 AM Subject: Re: [Tutor] printing variable name and value? > On Sun, 28 May 2000, Emile van Sebille wrote: > > Does this do it? > > > > def show_vars(varlist, namespace): > > for var in varlist: > > print "%s = %s" % (var, namespace[var]) > Hello, thanks for the idea. I is not exactly what I wanted, but you have > tought me something: I was not aware of the possibility of retrieving the > namespaces az dictionaries. > Thanks, > Gabor > >

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best practice
by Timothy Wilson May 31, 2000

May 31, 2000

Hi everyone, Thanks for all of the suggestions with my little prime number program. As several people pointed out, the problem was that raw_input gets a string which sqrt() chokes on. In the interpreter, all it well because the function gets called directly with an integer. OK, problem solved. That brings up another very picky question though. Where should I handle these type difficulties? Here's another little program I was playing around with that takes an integer and returns a list of the integer's factors. The algorithm is crude, but effective. wilson@beethoven modules]$ cat factor.py # This function factors an integer and returns a list from math import * def factor(number): factors = [1, int(number)] for i in range(2, sqrt(number) + 1): if number % i == 0: factors.append(i) if i != number/i: # catch duplicates factors.append(int(number/i)) factors.sort() return factors if __name__ == '__main__': number = raw_input("Factor what? ") print factor(float(number)) As you can see, I convert the raw_input to a float before passing it to the function. Also, I have a couple of int() functions in my factor function to make sure that the list which is returned is a list of integers. **When run from the interpreter, those int()s aren't needed.** So here's the question (it's about time :-). Is it better python practice to make those type conversion outside the function or inside as I've done? Should the functions be made as "pure" as possible? It seems to me that for maximum efficiency, a rule of thumb should be that functions should be made to work in the interpreter with a minimum of fuss. The programmer who uses the function (or module) should be the one who concerns himself with the "types" of variables that are passed. Does this make any sense? (I've been grading 10-page research papers from 9th graders for the last couple hours. It can cause your head to swim.) -Tim -- Tim Wilson | Visit Sibley online: | Check out: Henry Sibley HS | http://www.isd197.k12.mn.us/ | http://www.zope.org/ W. St. Paul, MN | | http://slashdot.org/ wilson(a)visi.com | <dtml-var pithy_quote> | http://linux.com/

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String searching
by André Dahlqvist May 31, 2000

May 31, 2000

Hi everyone, I'm trying to find out if a certain word in a string is a hyperlink, in other words if it starts with http:// or ftp://. I've come up with a way that works, but I think there must be some less uglier way of doing this. Here's the solution I use now: for word in string.split(text): if "http://" == word[0:7] or "ftp://" == word[0:6] do stuff with word... The test itself is what I think is ugly, and I would have prefered to use something like: if "http://" or "ftp://" in string.split(text): get the whole word that matched... But I don't know how to get this whole match. I would be greatful for any advice. -- // André =================================================================== André Dahlqvist <andre(a)beta.telenordia.se> GnuPG Key ID: 0x70A2994A Fingerprint: E947 3297 331C CA30 5B88 EDF2 A830 3EBE 70A2 994A ===================================================================

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Re: [Tutor] String searching
by André Dahlqvist May 31, 2000

May 31, 2000

> In Python 1.6, you will be able to use if word.startswith("http://"): ... > That would look a bit nicer, but isn't available yet. That would be nice indeed. And even after Python 1.6 is out I can't really expect people to have the latest python interpreter installed. Or is it showhow backwards compatible? > There are actually a lot more types of URIs and they don't all use '://', > but this sort of thing is good enough for most purposes, I suppose :) Actually for my needs ftp:// and http:// will do, the rest of them are very unlikely to show up. Thanks for the tips! -- // André

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Remove me from your mailing list please
by tim May 30, 2000

May 30, 2000

Please remove me from your mailing list please. Thanks a lot. tim ____________________________________________________________________ Get your own FREE, personal Netscape WebMail account today at http://webmail.netscape.com.

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Re: [Tutor] why the error?
by Wesley J. Chun May 30, 2000

May 30, 2000

> Date: Tue, 30 May 2000 14:41:29 -0500 (CDT) > From: Timothy Wilson <wilson(a)visi.com> > > I wrote a little function that determines whether a given number is prime or > not. (I'm pretty sure the algorithm is correct.) > > --snip-- > from math import * > > def isPrime(number): > for j in range(2, sqrt(number)+1): > if number % j == 0: > return 0 > return 1 > > if __name__ == '__main__': > number = raw_input("Which number? ") > if isPrime(number): > print "%i is prime." % number > print "%i is not prime." % number > --snip-- > > This code seems to work perfectly when imported in the interpretor. When I > run it by typing 'python prime.py', I get: > > [wilsont@galileo python]$ python prime.py > Which number? 11 > Traceback (innermost last): > File "prime.py", line 15, in ? > if isPrime(number): > File "prime.py", line 8, in isPrime > for j in range(2, sqrt(number)+1): > TypeError: illegal argument type for built-in operation > > Any hints? Why the difference? well, guess what. it should *not* have worked in the interpreter either. the problem with the code is here: > for j in range(2, sqrt(number)+1): the reason why you get a TypeError is because the sqrt() function expects a floating point number. you passed in a string. the string comes from raw_input(): > number = raw_input("Which number? ") the raw_input() built-in function returns a raw string of what the user enters. to fix the bug, you have two choices: 1) leave it as a string input from the user using raw_input() and convert that value to a float, i.e. you can do it in different places, i.e. number = float(raw_input("Which number? ")) or if isPrime((float(number)): or even for j in range(2, sqrt(float(number))+1): note that if you are using an older version of python where strings are not accepted input for float(), you would have to use string.atof(). (2) use input() to evaluate the string expression input. input() is really the same as eval(raw_input()). so if you type in any object, they will be represented as such by eval() and returned, i.e. if the user enters an int, you can an int, if they enter a list, you get a list, etc. i would probably recommend option (1) because at least you are guaranteed you get a float out of it. finally, i am not familiar with the "%i" directive for the string format operator: > print "%i is prime." % number do you mean "%d" for integer? hope this helps!! -wesley "Core Python Programming", Prentice-Hall, TBP Summer 2000 wesley.j.chun :: wesc(a)alpha.ece.ucsb.edu cyberweb.consulting :: silicon.valley, ca http://www.roadkill.com/~wesc/cyberweb/

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Add me
by Jorge Eldis May 30, 2000

May 30, 2000

Add me

2 1

(no subject)
by Carsten Jensen May 30, 2000

May 30, 2000

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