Simple Queue in Linked list

Author: saarikabhasi

queue/linked-list-implementation/simpleQ-in-LL.py

@@ -0,0 +1,90 @@
+"""
+Implementing queue in linked list 
+
+self.front points to node which is next in line to be removed
+self.rear points to most recently entered node
+self.size counts queue entries
+self.maxSize is the maximum possible entries in queue
+
+
+"""
+
+class Node:
+    def __init__(self,item) -> None:
+        self.item = item
+        self.next = None
+        
+class Queue:
+    def __init__(self,maxSize) -> None:
+        self.front = None
+        self.rear = None
+        self.size = 0
+        self.maxSize = maxSize
+
+    def isEmpty(self):
+        return self.front == self.rear == None
+    def isFull(self):
+        return self.size == self.maxSize
+
+    def enqueue(self,data):
+        newNode = Node(data)
+        if not self.isFull():
+            #Q is not Full yet
+            if self.isEmpty():
+                # First entry 
+                self.front  = newNode
+            else:
+                # other entry exist
+                lastNode = self.front
+                while lastNode.next:
+                    lastNode = lastNode.next
+
+                lastNode.next = newNode
+                
+
+            self.rear = newNode
+            self.size+=1
+        else:
+            print('Enqueue failed as Queue is full') 
+        return        
+    
+    def dequeue(self):
+        if not self.isEmpty():
+            #last node
+  
+            self.front = self.front.next
+            self.size -=1
+            if self.front == None and self.size == 0:
+                #removed last node, list empty
+                self.rear = None 
+        else:
+            print("Dequeue fail, Queue is empty")
+        return  
+
+    def print(self):
+        size = self.size
+        p = self.front
+        flag = True
+        while size>=0 and p:
+            if flag:
+                print("to be removed is:",p.item)
+                flag=False
+            else:
+                print(p.item)    
+            p = p.next
+        print("__________")
+        return
+        
+
+        
+
+q = Queue(3)
+q.enqueue(1)
+q.enqueue(2)
+q.enqueue(3)
+q.print()
+q.dequeue()
+q.dequeue()
+q.dequeue()
+q.dequeue()
+q.print()