How can I create a sequence of tuples?

Question

I want to create a sequence of tuples of varying lengths. For example sometimes I might want a sequence with 3 tuples:

((0.0, 100.0), (0.0, 100.0), (0.0,100.0))

other times I might want a sequence with 4 tuples:

((0.0, 100.0), (0.0, 100.0), (0.0, 100.0), (0.0, 100.0))

I'm using Python 2.7. What is the quickest way to do this?

Answer 1

Just use an ordinary generator with range :

>>> tuple((0., 100.) for _ in range(3))
((0.0, 100.0), (0.0, 100.0), (0.0, 100.0))
>>> tuple((0., 100.) for _ in range(4))
((0.0, 100.0), (0.0, 100.0), (0.0, 100.0), (0.0, 100.0))

You could also use multiplication, but this can have unintended effects if you decide to include mutable objects, as they are duplicated by reference:

>>> ((0., 100.),) * 3
((0.0, 100.0), (0.0, 100.0), (0.0, 100.0))
>>> ((0., 100.),) * 4
((0.0, 100.0), (0.0, 100.0), (0.0, 100.0), (0.0, 100.0))
>>> a = ((0., 100., []),) * 3
>>> a
((0.0, 100.0, []), (0.0, 100.0, []), (0.0, 100.0, []))
>>> a[0][-1].append(1)
>>> a
((0.0, 100.0, [1]), (0.0, 100.0, [1]), (0.0, 100.0, [1]))