Question

I can't figure out how to define a list as part of a program. The best I can do is create the empty list prior to making the program. Can anyone tell me how to do that? Here's what I mean: http://dpaste.com/hold/605253/
(it's assignment 2 problem 3)

Answer 1

that's how you do it.

Answer 2

yeah, you got it, there's nothing wrong or odd about creating an empty list. in fact if you call the list.append(x) method before you have a list, Python will raise an exception I think.

you can also create a non empty list if you know what's going to go into it ahead of time:
listName = [x, y, 'a', 'b', variableName, etc]

also, it's not a good habit to capitalize the first letter of a variable or object, in some languages that will cause unwanted effects. lowercaseThenUpperCaseIfMoreThanOneWord

enough rambling. enjoy!

Answer 3

jesse.bo- what version of python are you using? When I use the "list.append(x) " function, I get an error in Python 2.7.2 saying that "append isn't valid.

Answer 4

are you typing in 'list.append(x)' exactly, without substituting the 'list' part for the identifier of an actual list you need to use?

a = ['hello']
a.append('mom')
is totally valid

Answer 5

yeah, sorry, when I said list.append, i meant to substitute 'list' for your list name. probably should have written listName.append(value or expression)

I am using 2.7 and 3.1, but from what I hear, they have put most of the 3.x improvements into the 2.7 build, so you can use 3 syntax even if you are using 2.7, but not necessarily visa versa, i.e. you can't type:
print 'hello World' #you can't type this in build 3.x
print('hello world') would work in both 3 and 2.7. It was converted to a function in 3

but I digress.

Answer 6

Doh! My problem was not with syntax. It turns out that Python doesn't know how to append a list with a non-existent value! Oops- I guess I need to figure out how to generate a value before I try to stick it into a list.