How can I extend a set with a tuple?

Question

Unlike list.extend(L), there is no extend function in set. How can I extend a tuple to a set in pythonic way?

t1 = (1, 2, 3)
t2 = (3, 4, 5)
t3 = (5, 6, 7)

s = set()
s.add(t1)
s.add(t2)
s.add(t3)

print s
set([(3, 4, 5), (5, 6, 7), (1, 2, 3)])

My expected result is:

set([1, 2, 3, 4, 5, 6, 7])

My solutions is something like:

for item in t1 :
    s.add(item)

Answer 1

Try the union method -

t1 = (1, 2, 3)
t2 = (3, 4, 5)
t3 = (5, 6, 7)
s= set()
s = s.union(t1)
s = s.union(t2)
s = s.union(t3)
s
>>> set([1, 2, 3, 4, 5, 6, 7])

Or as indicated in the comments , cleaner method -

s = set().union(t1, t2, t3)

Answer 2

Either:

>>> newSet = s.union(t1, t2, t3)
set([1, 2, 3, 4, 5, 6, 7])

Or the following, which actually updates without any assignation needed

>>> s.update( t1, t2, t3)
>>> s
set([1, 2, 3, 4, 5, 6, 7])