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.
These two languages are so similar that any strong preference will be mostly subjective. They are both the correct answer.
Ruby or Python instead of PHP?