Using generator expressions to directly create tuples is a not so good idea performance-wise. Use it only if you have memory issues because it is not very performant. Using tuple([list comprenension]) is at most twice as fast.

# -*- coding: utf-8; mode: yaml; indent-tabs-mode: nil; -*-

# A top-level duplicate

%YAML 1.1
---

top:
  subkey1: the value

other:
  key2: another value

top:
  subkey2: the value