DDPT is an array of integers, as evidenced in this line:
DDPT = [int(round(pt*TCV)) for pt in [.3,.5,.2]]
DDPT[PT] is some integer, and you are trying to iterate through that. Hence the error.
I would recommend giving your variables more descriptive names so these issues are easier to debug.
for num_iters in DDPT:
for iteration in range(num_iters):