Removed spaces from top-level directory names.

Spaces tend to cause annoyances in a Unix-style shell environment.
This change fixes that.

03_Animal/python/animal.py

@@ -0,0 +1,192 @@
+########################################################
+#
+# Animal
+#
+# From: Basic computer Games(1978)
+#
+#    Unlike other computer games in which the computer
+#   picks a number or letter and you must guess what it is,
+#   in this game you think of an animal and the computer asks
+#   you questions and tries to guess the name of your animal.
+#   If the computer guesses incorrectly, it will ask you for a
+#   question that differentiates the animal it guessed
+#   from the one you were thinking of. In this way the
+#   computer "learns" new animals. Questions to differentiate
+#   new animals should be input without a question mark.
+#    This version of the game does not have a SAVE feature.
+#   If your sistem allows, you may modify the program to
+#   save array A$, then reload the array  when you want
+#   to play the game again. This way you can save what the
+#   computer learns over a series of games.
+#    At any time if you reply 'LIST' to the question "ARE YOU
+#   THINKING OF AN ANIMAL", the computer will tell you all the
+#   animals it knows so far.
+#    The program starts originally by knowing only FISH and BIRD.
+#   As you build up a file of animals you should use broad,
+#   general questions first and then narrow down to more specific
+#   ones with later animals. For example, If an elephant was to be
+#   your first animal, the computer would ask for a question to distinguish
+#   an elephant from a bird. Naturally there are hundreds of possibilities,
+#   however, if you plan to build a large file of animals a good question
+#   would be "IS IT A MAMAL".
+#    This program can be easily modified to deal with categories of
+#   things other than animals by simply modifying the initial data
+#   in Line 530 and the dialogue references to animal in Lines 10,
+#   40, 50, 130, 230, 240 and 600. In an educational environment, this
+#   would be a valuable program to teach the distinguishing chacteristics
+#   of many classes of objects -- rock formations, geography, marine life,
+#   cell structures, etc.
+#    Originally developed by Arthur Luehrmann at Dartmouth College,
+#   Animal was subsequently shortened and modified by Nathan Teichholtz at
+#   DEC and Steve North at Creative Computing
+#
+########################################################
+
+
+class Node:
+    """
+    Node 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 list_known_animals(root_node):
+    # Traversing the tree by recursion until we reach the leafs
+    if root_node == None:
+        return
+
+    if root_node.is_leaf():
+        print(root_node.text, end=' '*11)
+        return
+
+    if root_node.yes_node:
+        list_known_animals(root_node.yes_node)
+
+    if root_node.no_node:
+        list_known_animals(root_node.no_node)
+
+
+def parse_input(message, check_list, root_node):
+    # only accepts yes or no inputs and recognizes list operation
+    correct_input = False
+    while not correct_input:
+        try:
+            inp = input(message)
+
+            if check_list and inp.lower() == 'list':
+                print('Animals I already know are:')
+                list_known_animals(root_node)
+                print('\n')
+
+            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
+
+
+def initial_message():
+    print(' '*32 + 'Animal')
+    print(' '*15 + 'Creative Computing Morristown, New Jersey\n')
+    print('Play ´Guess the Animal´')
+    print('Think of an animal and the computer will try to guess it.\n')
+
+
+# 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
+initial_message()
+keep_playing = parse_input(
+    'Are you thinking of an animal? ', True, root) == '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, False, None)
+
+            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), False, None)
+            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), False, None)
+
+                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? ', True, root) == 'y'
+
+
+########################################################
+# Porting Notes
+#
+#   The data structure used for storing questions and
+#   animals is a binary tree where each non-leaf node
+#   has a question, while the leafs store the animals.
+#
+#   As the original program, this program doesn't store
+#   old questions and animals. A good modification would
+#   be to add a database to store the tree.
+#    Also as the original program, this one can be easily
+#   modified to not only make guesses about animals, by
+#   modyfing the initial data of the tree, the questions
+#   that are asked to the user and the initial message
+#   function  (Lines 120 to 130, 135, 158, 160, 168, 173)
+
+########################################################