Language selection for new projects

[Limey Drink]

Hi

I have used recently for the odd shell scrit hear and there but nothing
really serious.
Software I have previously written has been in VB(urgh) and C++.

I have been thinking of changing my primary development landguage for some
time, this is partly because my software ideally needs to be cross platform
and partly because I feel there must be better cleaner/programmer friendly
languages out there so i have decided to bite the bullit and go for the
switch.

I was going to choose Java, but I like Python.

What are your thoughts on the viability of using Python on a fairly large
projects, I'm talking GUI, RDBMS access, COMMS.

Basically how does the language scale up in terms of portability,
performance, programmr friendliness(in terms of real sized programs not
small scripts) to Java.
My last concern is source code, is there any way to protect it from prying
eyes, obviously Java does have these issues but at least you can byte code
compile it.

Thanks in advance