IPython cell magic with the %%mmd command allows to include python expressions (and other things) in a markdown text.
The cells can be edited as markdown, python expression are indicated by the double mustaches.
pip install magic-markown
in your notebook:
%load_ext magic_markdown
then you can create magic markdown cells by beginning a cell like this:
%%mmd
Write markdown and insert python code whereever you need: {{"hello".upper()}}. You can also access variables and functions you defined or imported before. Checkout the full example.