Sets aren't something you import, you just use them. I can't tell if you're trying to use a set with a single value of the data type list or you want the first set to contain the values 20, 21, 22, etc. This covers how to declare sets https://www.w3schools.com/python/python_sets.asp
On the Maximo imports, you almost guaranteed can remove MboRemote, MboSetRemote, & MboConstants. The data types of java objects don't need to be imported unless you need to use their constructor explicitly (IE you have a line like myvariable=MboSetRemote()). If you use something like myvariable=mbo.getMboSet("RELATIONSHIP").getMbo(0), the fact that it is a MboRemote doesn't matter and doesn't require an import.
MboConstants is something that you can import to use MboConstants.NOACCESSCHECK for example. But what most people aren't aware is that each Mbo has this implemented so you can call mbo.NOACCESSCHECK for example without needing the additional import.