I need a list in the form of adjacency list that contains all zip codes in the United States that each has a list of adjacent zip codes. I tried searching for it on the internet. Many of them only provide a list, but none of them had a list showing the adjacent list of zip codes. How do I find something like that?
The closest thing I found is a list of counties and their adjacent counties. There are several websites that I believe that they have the information but they are using it for applets like this website, http://www.freemaptools.com/find-zip-codes-inside-radius.htm
If no data is available, could I use the counties list to generate the said list?
EDIT: OP here, I was new to the whole GIS system. I don't know which software to use. I decided to try ArcGIS trial. I downloaded ArcGIS and that .lpk file. But I have no idea how to properly load .lpk in a python script and run PolygonNeighbors_analysis function. ArcPy Documentation and Google are not giving me a clear answer. Can anyone show me how to load .lpk package and use the function? Thanks
EDIT2: I think I should have mentioned that I want that list in a simple .txt file. I think I could do this with ArcPY to collect all zip codes and their neighbors, then store it in the .txt file. My current obstacle to this is that I have no idea how to load .lpk file to ArcPY.
EDIT3: I got it to work! By following what Barrett described, I got a raw .txt file of zip codes and their neighbors. I cleaned it up with my small program. It looks good. Thanks for help!