Solved queue.get() effeciency problem

data_structures/queue/queue.py

@@ -6,27 +6,71 @@ class Queue:
     Queue follows First-In-First-Out methodology, i.e., the data item stored first will be accessed first.
 
     """
+    class __Node: # new addition part
+        """ used for double linked list logic of queue"""
+        """ should not available outside the class"""
+        def __init__(self,element,next = None,prev = None):
+            self.ele = element
+            self.next = next
 
-    def __init__(self):
-        self.entries = []
-        self.length = 0
-        self.front = 0
+    def __init__(self): # modified part
+
+        self.head = None # points to last pushed element (enqueue part)
+        self.length = 0 # number of elements in it
+        self.Tail = None # points to first pushed element (dequeue part)
+
+    def is_empty(self): # new addition part
+        """check is queue object is empty or not
+        return boolean
+        """
+        return self.length<=0
+
+    def put(self, item): # modified part
+        """add item to queue
 
-    def put(self, item):
-        self.entries.append(item)
-        self.length += 1
+        Args:
+            item (any): item to be  pushed
+        """
+        temp = self.__Node(item) # create new node
+
+        if self.is_empty():
+            # initialize the doubly linked list
+            self.head = temp
+            self.Tail = temp
+
+            self.length += 1 
+            return 
+        # already initialized so just add the item
 
-    def get(self):
-        if self.length <= 0:
-            return
+        self.head.next = temp # point to next element
+        self.head = self.head.next # move pointer to next element which is last pushed element
+
+        self.length += 1 
+        return 
+
+    def get(self): # modified part
+        """ pop the tail element and move the pointer one step ahead
+        """
+        if self.is_empty():
+            return 
+
         self.length -= 1
-        de_queued = self.entries[self.front]
-        self.entries = self.entries[1:]
-        return de_queued
+
+        temp = self.Tail
+        nex = self.Tail.next
+        self.Tail.next = None
+        self.Tail = nex
+
+        return temp.ele
+
+
 
     def rotate(self, rotation):
         for i in range(rotation):
             self.put(self.get())
 
     def size(self):
         return self.length
+
+    def __len__(self): # new addition part
+        return self.length