I'm considering learning a new language as an alternative to PHP. I'm considering Python and Ruby. Which one is a better language based on the following four criteria, and any other qualifiers you may have?

Which is more stable?
Which is more scaleable?
Which is more secure?
Which is easier to learn?

EDIT:
Keeping the original question intact, I'd like to add one more pair of questions.

Which is quicker to code with?
Which is quicker to learn? (Based on personal experience only please - to avoid holywars.)

EDIT2:
Sorry for not clarifying - mostly web development, some desktop programming would be a nice bonus.
I personally would prefer Ruby, as it goes wonderfully with the Rails framework and is a blast to learn and to work with.
I have only used Python a few times. While I know it is powerful, I have never really fallen in love with it the way I have with Ruby (and specifically the Rails framework)
Ruby or Python instead of PHP?