The best thing like this that I've found is DreamPie. The website is here, and you can get an idea of its look and feel there, but you are probably better off installing the version from Github. (I also have a fork on Bitbucket with some tweaks.)
DreamPie is a lightweight GUI wrapper around the interactive Python shell. It has a two-pane layout where you type code in one pane and the output (along with the executed code) appears in the other pane. It has some simple but handy features, such as autocompletion, the ability to display function/class documentation or source code in a tooltip, the ability to fold long output, etc.
However, there are a number of caveats. The main one is that to run it you have to use Python 2. DreamPie itself, as I said above, is a wrapper around Python, and it can wrap Python 3, so you can use DreamPie to use Python 3. But the wrapper itself only runs in Python 2, largely because it depends on pygtksourceview, which doesn't appear to be available for Python 3. So if you want to use Python 3 with it you need both Python 2 and Python 3 installed.
I've been using it for years and am pretty addicted to it. Unfortunately the original author doesn't seem to do much in the way of maintenance and the project is moribund. Nonetheless, it's an extremely useful tool. (More recently I've been working on creating something similar that can run on Python 3, but it's still a work in progrss.)