Why the output of this code is 4 ? Please explain

Question

Nums= set ([1,1,2,3,3,3,4])
Print (Len(nums))

Answer 1

"set” does not set the same item more than once. so for example:
items = set([“once”, “once”])
if I print “items” it will only show:
{“once”}.
So your set is setting 1:1, 1:2, 1:3 and 1:4. the length of 4 is 4 so you are seeing it print 4.

Answer 2

A set has no duplicate element.