# Making a collection of functions

I have a somewhat large collection of functions that I wrote myself to make some computations. They are all very much dependent on each other so if I ever want to use some subset of them, say when I'm working in some Jupyter notebook, I have to copy paste the whole bunch of them into a cell and evaluate it. This makes the notebook really bulky and ugly. Is there anyway I can make these functions into a package so that I can just import it in any jupyter notebook that's in the same folder to use those functions?