[python] How to join two sets in one line without using "|"

Assume that S and T are assigned sets. Without using the join operator |, how can I find the union of the two sets? This, for example, finds the intersection:

S = {1, 2, 3, 4}
T = {3, 4, 5, 6}
S_intersect_T = { i for i in S if i in T }

So how can I find the union of two sets in one line without using |?

You can use union method for sets: set.union(other_set)

Note that it returns a new set i.e it doesn't modify itself.