PyVi

So It's a Vim Clone

No, but it's like vim.

But It's an Editor, Right?

No, but you can use it to make an editor.

Uh, What?

PyVi is a library implementing vim-like keybindings, along with entities like (display-less) windows and buffers which can be embedded in other Python applications, including an editor, for one.

Rather than every application creating vim mode keybindings from scratch, you tell PyVi what a window corresponds to in your application, send PyVi your keyboard input, and inspect (and likely display) the contents of the window.