Calling all python gurus!

[Teh_Yodels]

Hello, fellow python scripters of which I am not really yet one of, I was unable to find a good totally python oriented forum, so I decided to post these questions here. I downloaded python about a week ago, and understand the basic loops, conditionals, functions etc. that make up the basis of python. I have decided, however, to try something a little more advanced than what I am capable of; I have gotten myself stuck in a number of places.

First- When using dictionaries, is it possible to change one value in the dictionary without changing the other (eg: in a list of people and their phone numbers, changing somebody's number)?

Second- can a string be divided up into substrings by spaces, so that a 'for' loop could do something for each word in a sentence, or to check and see if the same word was used twice?

So yeah, those are my questions. thanks in advance for any answers I might get,

Yodelz

[Redcore]

1) I'm not sure. I'm not a Python guru really (PHP, yes - Python, no) but I couldn't imagine that it's not possible in Python if it's possible with PHP.
2) http://docs.python.org/library/string.html#string.split