added circular queue code for python

circularQueue

@@ -1 +1,31 @@
+class Node(object):
+    def __init__(self, item = None):
+        self.item = [None] * 4
+        self.next = None
+        self.previous = None
 
+class CircularQueue(object):
+    def __init__(self):
+        self.length = 0
+        self.head = None
+        self.tail = None
+    def enqueue(self, x):
+        newNode = Node(x)
+        newNode.next = None
+        if self.head == None:
+            self.head = newNode
+            self.tail = newNode
+        elif self.length < 4:
+            self.tail.next = newNode
+            newNode.previous = self.tail
+            self.tail = newNode
+        else:
+            self.tail = (self.tail + 1) % 4
+        self.length += 1
+    def dequeue(self):
+        if self.count == 0:
+            print ("The Queue is empty!")
+        self.count -= 1
+        return self.item.pop()
+    def size(self):
+        return self.length