best way to compare contents of 2 lists?

[Esmail]

What is the best way to compare the *contents* of two different
lists regardless of their respective order? The lists will have
the same number of items, and be of the same type.

E.g. a trivial example (my lists will be larger),

a=[1, 2, 3]

b=[2, 3, 1]

should yield true if a==b

I suppose I could sort them and then compare them. I.e.,

sorted(a)==sorted(b)


I am wondering if there is a more efficient/preferred way to do so.

Thanks,
Esmail