Remove second nested element in nested tuple in Python

Question

I have a list of tuples with coordinates:

((3.5, -0.5), (3.5, 0.5))
((3.5, 0.5), (4.5, 0.5))
((4.5, 0.5), (4.5, 1.5))
((4.5, 1.5), (5.5, 1.5))
((5.5, -0.5), (