I stumbled across Pyspread the other day, a more recent attempt at a spreadsheet using Python at the cell-level. See http://manns.github.io/pyspread/.

  Pyspread expects Python expressions in its grid cells, which makes a spreadsheet
  specific language obsolete. Each cell returns a Python object that can be accessed
  from other cells. These objects can represent anything including lists or matrices.

I haven't used it yet, most of my personal spreadsheets are in Google Sheets and I'm not too keen to pull them out of Google Drive.