hi mike,
welcome to python. :-) your query is quite common amongst beginners,
and i have actually spend some time on this topic in my courses.
On 2/17/06, Michael Broe <[EMAIL PROTECTED]> wrote:
> I think I understand this sorting-a-list 'in place' stuff, and things
> of that kind (reversing for example); but I am finding it very
> difficult to get used to, since sorting a list doesn't return the
> sorted list as a value, but simply does the work as a side effect.
>
> def sort_print(L):
> print L.sort()
>
> def upper_print(s):
> print s.upper()
>
> (The fact that the second works and the first doesn't really does bug
> me as a newbie.)
as i hinted to above, this confusion happens quite regularly.
> Anyway, first question: is the fact that the first doesn't work
> purely a function of the fact that lists are mutable?
this is the primary reason. the side effect is also a reason why the
sorted() BIF (built-in function) was added to Python.
> Second question. Do I really have to write the sort_print() function
> like this:
if using sorted() doesn't work for you, then yes.
> Third question: is this in-place behavior of methods in effect
> restricted to lists, or are there other places I should be on the
> lookout for it?
since most all other Python types are immutable, no in-place
operations can occur, so this is not an issue.
and altho dictionaries are Python's other mutable type (ignoring sets
at the moment), ordering isn't a feature of hashes/mapping types, so
no one gets bitten there either.
hope this helps... a little!
-- wesley
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Core Python Programming", Prentice Hall, (c)2006,2001
http://corepython.com
wesley.j.chun :: wescpy-at-gmail.com
cyberweb.consulting : silicon valley, ca
http://cyberwebconsulting.com
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
