Python Vs Ruby On Rails : on Size
With disk space at the current price, size shouldn't matter. Give both a try and figure out which will be easier for you to learn and maintain. Despite the fact that people believe that when you know one language, you know all, that's only true as long as you write code on the "hello world" level.
I am planning to do a small web application that will be distributed as a single installable. I have plans to develop this application in either Python/Django or Ruby On Rails. (I am a Java/C++ programmer, hence both these languages are new to me). 
My main concern is about the size and simplicity of final installable (say setup.exe). I want it to be small in size and also should be able to pack all required components in it. 
Which one among Python/Django and Ruby On Rails is suitable for me?