I love Python.
You can quickly hack anything in a matter of minute and very efficiently.
There are libraries for everything, so you don't have to 're-invent the weel'
And code is so clean, it is just awesome.
I've learned it by myself mostly, it wasn't very hard since I already knew a few scripting languages.
Now I use it for the profesional projects where the language choice is mine, or my personnal projects.
I'm also member of a hacker team
http://big-daddy.fr/ and whenever I need to code an exploit I use python because of it's effectiveness and awesome network libraries (read "Twisted")
I'm still using python 2.7 though, because of some libraries not having been yet ported on python 3.
But anyway, you can't go wrong with python, it's definitively a great language.