recursive tree-building in python

tree.py

# Creates a binary tree of depth `d`. Each node is represented as a python `dict`,
# with the value of the key "leaf" as a boolean indicating whether or not the node is a leaf node.
def make_tree(d):
  assert d > 0
  if d == 1: return {"leaf": True}
  else: return {"leaf": False, "left": make_tree(d-1), "right": make_tree(d-1)}

make_tree(1)
# {'leaf': True}

make_tree(2)
# {'leaf': False,
#  'left': {'leaf': True},
#  'right': {'leaf': True}}

make_tree(3)
# {'leaf': False,
#  'left': {'leaf': False,
#           'left': {'leaf': True},
#           'right': {'leaf': True}},
#  'right': {'leaf': False,
#            'left': {'leaf': True},
#            'right': {'leaf': True}}}