def swap_fragment(self, seed):
"""Substitutes a random fragment with another with the same symbol"""
if seed.has_structure:
n_nodes = self.count_nodes(seed.structure)
self.to_swap = random.randint(2, n_nodes)
new_structure = self.recursive_swap(seed.structure)
new_seed = Seed(tree_to_string(new_structure))
new_seed.has_structure = True
new_seed.structure = new_structure
return new_seed
return seed
def delete_fragment(self, seed):
"""Deletes a random fragment"""
if seed.has_structure:
n_nodes = self.count_nodes(seed.structure)
self.to_delete = random.randint(2, n_nodes)
new_structure = self.recursive_delete(seed.structure)
new_seed = Seed(tree_to_string(new_structure))
new_seed.has_structure = True
new_seed.structure = new_structure
# do not return an empty new_seed
if not new_seed.data: return seed
else: return new_seed
return seed