Nictk consist only of the two files __init__.py and constants.py in the folder /Nictk. If you want to try it without installing you can:

create your own folder
copy in it (as subfolders) the /Nictk and /Examples folders
create your own files in your folder (files in /Example folder import a _setup module which sets the path for import)

For installing it you can download the wheel or tar.gz files from the /dist folder and istall them with pip. Enter the folder in which the file have been downloaded and type (for mac/linux users):

python3 -m pip install nictk_pkg_python_gui-2.0.0-py3-none-any.whl

or

python3 -m pip install nictk-pkg-python-gui-2.0.0.tar.gz

the two methods are equivalent, but (according to Python documentation) installing from .whl file should be preferred.

Windows users should open a cmd console and substitute python3 with python.

Moreover you can also unzip the tar.gz file and experiment with the example files (in the /Examples folder).