class Rope:

  # Initializes the Rope to contain the provided string
  def __init__(self, data=""):
    self.data = data
    self.weight = len(data)
    self.right_child = None
    self.left_child = None

  # Adds the provided string to the end of this rope
  def __add__(self, other_rope):
    # Creates the new Rope that stores the new String
    new_rope = Rope()

    # Puts the two provided ropes as the children of the new rope
    new_rope.left_child = self
    new_rope.right_child = other_rope

    # Sets the weight of the new rope
    new_rope.weight = len(self)

    return new_rope

  # Finds the length of the current Rope
  def __len__(self):
    # Uses the fact that weight is the length of the left child
    # and adds it to the length of the right child recursively
    if (self.right_child):
      return self.weight + len(self.right_child)
    # Provides the base case for when there is no right child
    else:
      return self.weight

  # Returns the character at the given index
  def get(self, index):
    # If the weight of the current node is less than the index,
    # it is in the right subtree if it exists
    if (self.weight <= index and self.right_child):
      return self.right_child.get(index - self.weight)
    # Otherwise it is in the left subtree if it exists
    elif (self.left_child):
      return self.left_child.get(index)
    # If the node is a leaf node
    else:
      return self.data[index]

  # Returns the rope as a string
  def __str__(self):
    # Adds the left and right subtrees as strings recursively
    if (self.left_child and self.right_child):
      return self.left_child.__str__() + self.right_child.__str__()
    # The string representation of this subtree is equal to that of its left subtree
    elif (self.left_child):
      return self.left_child.__str__()
    # The string representation of this subtree is equal to that of its right subtree
    elif (self.right_child):
      return self.right_child.__str__()
    # It is a leaf node, so its string representation is just its data
    else:
      return self.data

  def lsplit(self, index):
    """
    returns only the left side of a split at $index
    """
    if index == 0:
      return Rope()  # Empty rope, nothing to the left of index 0
    if index == len(self):
      return self  # Entire rope, nothing to the right of the index
    if index == self.weight and self.left_child:
      return self.left_child  # the index is splitting at this weight, return just the left child
    if index > self.weight and self.right_child:
      if self.left_child:  # if index greater than weight,
        return self.left_child + self.right_child.lsplit(index - self.weight)  # split is to the right of weight
      else:  # so we call lsplit on right
        return self.right_child.lsplit(index - self.weight)  # child with our current weight
    if index < self.weight and self.left_child:  # removed
      return self.left_child.lsplit(index)
    else:
      return Rope(self.data[:index])

  def rsplit(self, index):
    """
    returns only the right side of a split at $index
    the entire function is the same as lsplit but for the right side
    """
    if index == 0:
      return self
    if index == len(self):
      return Rope()
    if index == self.weight and self.right_child:
      return self.right_child
    if index > self.weight and self.right_child:
      return self.right_child.rsplit(index - self.weight)
    if index < self.weight and self.left_child:
      if self.right_child:
        return self.left_child.rsplit(index) + self.right_child
      else:
        return self.left_child.rsplit(index)
    else:
      return Rope(self.data[index:])

  # Deletes the elements from index1 to index2
  def delete(self, index1, index2=None):
    if not index2:
      index2 = index1 + 1
    left = self.lsplit(index1)
    right = self.rsplit(index2)
    return left + right


# rope_1 = Rope("Davis MacDonald")
# rope_1.delete(5, 7)
# print(rope_1)

r2 = Rope("0123")
r3 = Rope("456")
r4 = r2 + r3
r5 = Rope("789")
r6 = Rope("0")
r7 = r5 + r6
r8 = r4 + r7
print(r8)
print(r8.delete(0))
print(r8.delete(1))
print(r8.delete(2))
print(r8.delete(3))
print(r8.delete(4))
print(r8.delete(5))
print(r8.delete(6))
print(r8.delete(7))
print(r8.delete(8))
print(r8.delete(0, 8))
print(r8.delete(1, 8))
print(r8.delete(3, 8))
print(r8.delete(2, 6))