reorganize dir

Signed-off-by: Mia Steinkirch <mia.steinkirch@gmail.com>

ebook_src/abstract_structures/queues/animal_shelter.py

@@ -0,0 +1,109 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+""" A class for an animal shelter with two queues"""
+
+
+class Node(object):
+    def __init__(self, animalName=None, animalKind=None, pointer=None):
+        self.animalName = animalName
+        self.animalKind = animalKind
+        self.pointer = pointer
+        self.timestamp = 0
+
+
+
+class AnimalShelter(object):
+    def __init__(self):
+        self.headCat = None
+        self.headDog = None
+        self.tailCat = None
+        self.tailDog = None
+        self.animalNumber = 0
+
+
+    # Queue any animal
+
+    def enqueue(self, animalName, animalKind):
+        self.animalNumber += 1
+        newAnimal = Node(animalName, animalKind)
+        newAnimal.timestamp = self.animalNumber
+
+        if animalKind == 'cat':
+            if not self.headCat:
+                self.headCat = newAnimal
+            if self.tailCat:
+                self.tailCat.pointer = newAnimal
+            self.tailCat = newAnimal
+
+        elif animalKind == 'dog':
+            if not self.headDog:
+                self.headDog = newAnimal
+            if self.tailDog:
+                self.tailDog.pointer = newAnimal
+            self.tailDog = newAnimal
+
+
+    # Dequeue methods
+
+    def dequeueDog(self):
+        if self.headDog:
+            newAnimal = self.headDog
+            self.headDog = newAnimal.pointer
+            return str(newAnimal.animalName)
+        else:
+            return 'No Dogs!'
+
+
+    def dequeueCat(self):
+        if self.headCat:
+            newAnimal = self.headCat
+            self.headCat = newAnimal.pointer
+            return str(newAnimal.animalName)
+        else:
+            return 'No Cats!'
+
+
+    def dequeueAny(self):
+        if self.headCat and not self.headDog:
+            return self.dequeueCat()
+        elif self.headDog and not self.headCat:
+            return self.dequeueDog()
+        elif self.headDog and self.headCat:
+            if self.headDog.timestamp < self.headCat.timestamp:
+                return self.dequeueDog()
+            else:
+                return self.dequeueCat()
+        else:
+            return ('No Animals!')
+
+
+
+    def _print(self):
+        print("Cats:")
+        cats = self.headCat
+        while cats:
+            print(cats.animalName, cats.animalKind)
+            cats = cats.pointer
+        print("Dogs:")
+        dogs = self.headDog
+        while dogs:
+            print(dogs.animalName, dogs.animalKind)
+            dogs = dogs.pointer
+
+
+if __name__ == '__main__':
+
+    qs = AnimalShelter()
+    qs.enqueue('bob', 'cat')
+    qs.enqueue('mia', 'cat')
+    qs.enqueue('yoda', 'dog')
+    qs.enqueue('wolf', 'dog')
+    qs._print()
+
+    print("Deque one dog and one cat...")
+    qs.dequeueDog()
+    qs.dequeueCat()
+    qs._print()