How do I change elements in a list?

[kyosohma at gmail.com]

On Nov 6, 3:11 pm, "Just Another Victim of the Ambient Morality"
<ihates... at hotmail.com> wrote:
>     How do you change certain elements in a list?  I'm looking to do the
> Python equivalent of this Ruby code:
>
> ->  first = [1, 2]
> =>  [1, 2]
> ->  second = first
> =>  [1, 2]
> ->  first.map! {|i| i + 1}
> =>  [2, 3]
> ->  first
> =>  [2, 3]
> ->  second
> =>  [2, 3]
>
>     I need to change a list, in place, so other variables referencing that
> list also see the change.
>     Thank you...

You can "point" one variable name at another so that they both
reference the same list:

second = first

To change a list "in place", I usually do something like this:

first[someElement] = something-else

or

# change the first element in the list
first[0] = 55

See also

http://docs.python.org/tut/node7.html
http://www.diveintopython.org/native_data_types/lists.html
http://docs.python.org/lib/built-in-funcs.html

Mike