Regarding the first question, the ipynb
notebook format is not executable, so you have to export your code as Python. For this, click on FIle
then Download as
then Python (.py)
.
Regarding the second quiestion (foldable cells), you have to install and configure some extensions. From a terminal, type
sage -pip install jupyter_contrib_nbextensions
sage -jupyter contrib nbextension install --user
sage -pip install jupyter_nbextensions_configurator
sage -jupyter nbextensions_configurator enable --user
Then run a jupyter, click on Edit
then nbextensions config
at the bottom, then click to select Collapsible Headings
, and select the way you want it to work down the page.