for one frozenset can be used as key in a dict. it's a direct result of frozenset being immutable. if you want to prevent set being changed- e.g. think of tuple vs list.
If you can't explain it to a six year old, you don't understand it yourself, Albert Einstein
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs