** Python Support Thread **

[eterm]

Firstly, try raw_input(), secondly try forcing conversion to int, so actually use int(raw_input())

[Xhad]

Originally Posted by clowntable

I like that explaination a lot, thx.

You might also find this interesting: http://www.cs.utexas.edu/users/EWD/t...xx/EWD831.html

[sorrow]

Originally Posted by Neko

sorted(_dict, lamda x: (x["points"], x["percent"])) should do it.

*mutters about gmail spam filter*

Pretty close to what I ended up with:

ladder = sorted(ladder, key=lambda d: (-d['points'], -d['percent']))

Gotta love python.

[WeAreSamurai]

Hey guys. So sometimes I find that I want to use a function in a loop where it'll act on the arg only if it exists. Like for example do a loop on a list and keep going only until it finds out that the next index of that list doesn't exist. Or maybe the function operates on a list of various class objects, of which only some of those objects share a certain method. So if that object has that attribute, I want the function to be carried out, but if not, do nothing and move on to the next item in the list.

And the easiest way I can think of to do this is to use a try except. But I'm not sure if that's considered bad form, or if they're only supposed to be used to catch errors.

[Neko]

A lot of people in the python use try/catch for the type of situation you're describing. Personally I'm not a huge fan of it. I'd rather do something like:

for obj in objects:
    if hasattr(obj,"method_name"):
       obj.method_name()

That looks much nicer to me than

for obj in objects:
    try:
        obj.method_name()
    except AttributeError():
        pass

That said, in some cases (i.e. when the attribute almost always exists on the objects) there can be performance benefits to the latter method.

[tyler_cracker]

+1 neko's answer

two other techniques that seem applicable:

- design your class structure to get rid of this problem:

class Parent(object):
    def updateDatabse(self):
        pass

class HasADatabase(Parent):
    def updateDatabase(self):
        # do real database-y things

- for data

attribute = getattr(klass, 'attribute')
if attribute is not None:
    # do the things

[Mariogs37]

Trying to find the smallest number divisible by each of the numbers between 1 and 20. Here's my attempt:

x = 1

y = 1

while y < 21:

if x % y == 0:
y = y + 1
else:
x = x + 1
y = 1

print(str(x))

Issue is, when I run it, Python doesn't print anything...not sure why. Ideas?

[tyler_cracker]

use the [ code ] tags.

try putting a print inside your while loop so you can see what x and y are doing.

[myNameIsInga]

Originally Posted by Mariogs37

Trying to find the smallest number divisible by each of the numbers between 1 and 20. Here's my attempt:

x = 1

y = 1

while y < 21:

if x % y == 0:
y = y + 1
else:
x = x + 1
y = 1

print(str(x))

Issue is, when I run it, Python doesn't print anything...not sure why. Ideas?

Does the program exit? If it doesn't it means that y never reaches 21 and you have an infinite loop. I'm not a python developer but it looks to me like the print statement is not in the loop, given the indentation, so if you are stuck in the loop the print never executes.

[Mariogs37]

Should have used the code tags but have sorted out the issue, thanks guys.

On a dif not, why do the vowels below need quotes around them. I would have done it without...

secret = input("Type something amusing: ")

count_vowels = 0
count_vowel_pairs = 0

last_char_was_vowel = False


for each_letter in secret.lower():
    print(each_letter)
    if ( each_letter == "a"
         or each_letter == "e"
         or each_letter == "i"
         or each_letter == "o"
         or each_letter == "u" ) :

        count_vowels = count_vowels + 1

Midterm tomorrow so trying to iron these little things out.

Thanks again, you guys have been rly helpful!

-Mariogs

[Xhad]

a

This is a variable named "a".

"a"

This is a string comprising the letter "a".

[Colombo]

I am going to try to write a GUI program for my fantasy football leagues' live drafts this year.

My first though was to write it in javascript and run it on localhost, but I've never worked with python GUI stuff so I'd like to learn it.

Anyone have any experience/recommendations for which GUI package to use? It seems like there are many options - with TkInter being the stdlib one.

The program should be fairly simple and not very intensive. I'll simply have a form which holds all of the players and various information about them, a "DRAFT ME" button, and a second page/tab which lists the big board (where and to which team each player was drafted).

[Mariogs37]

OK, so you'd only do that when comparing strings. When comparing integers, you wouldn't use quotes...yeah?

[myNameIsInga]

Originally Posted by Mariogs37

OK, so you'd only do that when comparing strings. When comparing integers, you wouldn't use quotes...yeah?

Yes. with no quotes you are comparing something to a variable. that is you are comparing something to the content in the variable. With the quotes you are not comparing to a variable but rather to a string. If you want to compare something with a particular integer you could simply type the integer (like 45), although that might not be good coding practice

[Xhad]

a = 5
b = "a"

a == 5 #True
"a" == 5 #False
a == "5" #False
b == 5 #False
b == a #False
b == "a" #True