add link to the new revision of my book, organize the folders to add further examples

src/examples_book/adt/queues/queue.py

@@ -0,0 +1,39 @@
+#!/usr/bin/python3
+# mari von steinkirch @2013
+# steinkirch at gmail
+
+
+class Queue(object):
+    ''' a class for a queue '''
+    def __init__(self):
+        self.items = []
+
+    def isEmpty(self):
+        return self.items == []
+
+    def enqueue(self, item):
+        self.items.insert(0, item)
+
+    def dequeue(self):
+        return self.items.pop()
+
+    def size(self):
+        return len(self.items)
+        
+    def peek(self):
+        return self.items[-1]
+
+
+def main():
+    queue = Queue()
+    queue.enqueue(1)
+    queue.enqueue(2)
+    queue.enqueue(3)
+    print(queue.size())    
+    print(queue.peek())   
+    print(queue.dequeue())  
+    print(queue.peek())    
+
+
+if __name__ == '__main__':
+    main()