Files
basic-computer-games/03 Animal/python/animal.py
2021-03-01 19:25:25 -03:00

96 lines
2.9 KiB
Python

class Node:
"""
Nodes of the binary tree of questions.
"""
def __init__(self, text, yes_node, no_node):
# the nodes that are leafs have as text the animal's name, otherwise
# a yes/no question
self.text = text
self.yes_node = yes_node
self.no_node = no_node
def update_node(self, new_question, answer_new_ques, new_animal):
# update the leaf with a question
old_animal = self.text
# we replace the animal with a new question
self.text = new_question
if answer_new_ques == 'y':
self.yes_node = Node(new_animal, None, None)
self.no_node = Node(old_animal, None, None)
else:
self.yes_node = Node(old_animal, None, None)
self.no_node = Node(new_animal, None, None)
# the leafs have as children None
def is_leaf(self):
return self.yes_node == None and self.no_node == None
def parse_input(message):
# only accepts yes or no inputs
correct_input = False
while not correct_input:
try:
inp = input(message)
token = inp[0].lower()
if token == 'y' or token == 'n':
correct_input = True
except IndexError:
pass
return token
def avoid_void_input(message):
answer = ''
while answer == '':
answer = input(message)
return answer
# Initial tree
yes_child = Node('Fish', None, None)
no_child = Node('Bird', None, None)
root = Node('Does it swim?', yes_child, no_child)
# Main loop of game
keep_playing = parse_input('Are you thinking of an animal?') == 'y'
while keep_playing:
keep_asking = True
# Start traversing the tree by the root
actual_node = root
while keep_asking:
if not actual_node.is_leaf():
# we have to keep asking i.e. traversing nodes
answer = parse_input(actual_node.text)
if answer == 'y':
actual_node = actual_node.yes_node
else:
actual_node = actual_node.no_node
else:
# we have reached a possible answer
answer = parse_input('Is it a {}?'.format(actual_node.text))
if answer == 'n':
# add the new animal to the tree
new_animal = avoid_void_input(
'The animal you were thinking of was a ?')
new_question = avoid_void_input(
'Please type in a question that would distinguish a {} from a {}:'.format(new_animal, actual_node.text))
answer_new_question = parse_input(
'for a {} the answer would be:'.format(new_animal))
actual_node.update_node(
new_question+'?', answer_new_question, new_animal)
else:
print("Why not try another animal?")
keep_asking = False
keep_playing = parse_input('Are you thinking of an animal?') == 'y'