Anecdata: in Python I used to (and still do to some extent) practice TDD very conscientiously because I felt it really helped me structure my programs well and

Anecdata: in Python I used to (and still do to some extent) practice TDD very conscientiously because I felt it really helped me structure my programs well and get them "correct my construction". One of the reasons for moving to Haskell was that the type system has the same effect at a lower cost (once the barrier to entry of learning about the type system has been crossed).