Java > Python
I hate python's syntax yet I use it anyway. There's alot you can accomplish with Java than python but requires more work. Python is more so a scripting language and relies upon another language (C/C++). Python is flexible so that's why it's easier to understand / use and easier to get a project started, which is why pen-testing it 10x easier than java. but I personally think java is better than python. With java you can make apps cross platform, mac, linux, Windows even other machinery.
Java attracted me with creating android apps