Cannot install openslide-python on google datalabs Jupyter notebook

I am trying to install openslide-python on google datalabs Jupyter notebook using: !apt-get install python-openslide

It runs, until it prints out:

   Need to get 13.0 MB of archives.
   After this operation, 44.7 MB of additional disk space will be used.
   Do you want to continue? [Y/n]

I type in Y in the next cell, and hit run. It says running... but nothing seems to happen. How do it get to install python-openslide here ?

Please can you try the following which includes the -y option?

!apt-get install -y python-openslide

Here is the definition of the -y option for apt-get from http://manpages.ubuntu.com/manpages/wily/man8/apt-get.8.html.

   -y, --yes, --assume-yes
       Automatic yes to prompts; assume "yes" as answer to all prompts and
       run non-interactively. If an undesirable situation, such as
       changing a held package, trying to install a unauthenticated
       package or removing an essential package occurs then apt-get will
       abort. Configuration Item: APT::Get::Assume-Yes.