Merge pull request #190 from jyotsana19/master

Added Dequeue in Python

data_structures/Queue/DeQueue.py

@@ -0,0 +1,39 @@
+# Python code to demonstrate working of 
+# extend(), extendleft(), rotate(), reverse()
+ 
+# importing "collections" for deque operations
+import collections
+ 
+# initializing deque
+de = collections.deque([1, 2, 3,])
+ 
+# using extend() to add numbers to right end 
+# adds 4,5,6 to right end
+de.extend([4,5,6])
+ 
+# printing modified deque
+print ("The deque after extending deque at end is : ")
+print (de)
+ 
+# using extendleft() to add numbers to left end 
+# adds 7,8,9 to right end
+de.extendleft([7,8,9])
+ 
+# printing modified deque
+print ("The deque after extending deque at beginning is : ")
+print (de)
+ 
+# using rotate() to rotate the deque
+# rotates by 3 to left
+de.rotate(-3)
+ 
+# printing modified deque
+print ("The deque after rotating deque is : ")
+print (de)
+ 
+# using reverse() to reverse the deque
+de.reverse()
+ 
+# printing modified deque
+print ("The deque after reversing deque is : ")
+print (de)