$ sudo apt-get update
$ sudo apt-get install python-itsdangerous 

python-itsdangerous is installed in your system.

Make ensure the python-itsdangerous package were installed using the commands given below,

$ sudo dpkg-query -l | grep python-itsdangerous *

You will get with python-itsdangerous package name, version, architecture and description in a table

python-itsdangerous package basic information: