Add queue data structure

Author: Bakhtiyor Ruziev

data_structures/queue/queue.py

@@ -0,0 +1,30 @@
+class Queue:
+    """
+    Queue is an abstract data structure, somewhat similar to Stacks.
+    Unlike stacks, a queue is open at both its ends. One end is always used to insert data (enqueue)
+    and the other is used to remove data (dequeue).
+    Queue follows First-In-First-Out methodology, i.e., the data item stored first will be accessed first.
+
+    """
+
+    def __init__(self):
+        self.entries = []
+        self.length = 0
+        self.front = 0
+
+    def put(self, item):
+        self.entries.append(item)
+        self.length += 1
+
+    def get(self):
+        self.length -= 1
+        de_queued = self.entries[self.front]
+        self.entries = self.entries[1:]
+        return de_queued
+
+    def rotate(self, rotation):
+        for i in range(rotation):
+            self.put(self.get())
+
+    def size(self):
+        return self.length