Added three files .

DSA/circular linklist

@@ -0,0 +1,54 @@
+class Node:    
+  def __init__(self,data):    
+    self.data = data;    
+    self.next = None;    
+
+class CreateList:    
+  #Declaring head and tail pointer as null.    
+  def __init__(self):    
+    self.head = Node(None);    
+    self.tail = Node(None);    
+    self.head.next = self.tail;    
+    self.tail.next = self.head;    
+
+  #This function will add the new node at the end of the list.    
+  def add(self,data):    
+    newNode = Node(data);    
+    #Checks if the list is empty.    
+    if self.head.data is None:    
+      #If list is empty, both head and tail would point to new node.    
+      self.head = newNode;    
+      self.tail = newNode;    
+      newNode.next = self.head;    
+    else:    
+      #tail will point to new node.    
+      self.tail.next = newNode;    
+      #New node will become new tail.    
+      self.tail = newNode;    
+      #Since, it is circular linked list tail will point to head.    
+      self.tail.next = self.head;    
+
+  #Displays all the nodes in the list    
+  def display(self):    
+    current = self.head;    
+    if self.head is None:    
+      print("List is empty");    
+      return;    
+    else:    
+        print("Nodes of the circular linked list: ");    
+        #Prints each node by incrementing pointer.    
+        print(current.data),    
+        while(current.next != self.head):    
+            current = current.next;    
+            print(current.data),    
+
+
+class CircularLinkedList:    
+  cl = CreateList();    
+  #Adds data to the list    
+  cl.add(1);    
+  cl.add(2);    
+  cl.add(3);    
+  cl.add(4);    
+  #Displays all the nodes present in the list    
+  cl.display();    

Recursion/lucky_Numbers using recursion.py

@@ -0,0 +1,28 @@
+#User function Template for python3
+
+
+class Solution:
+    def lucky(self,n,i):
+        if(n%i==0):
+            return False
+        elif(n<i):
+            return True
+        p=n-(n//i)
+        return self.lucky(p,i+1)
+    def isLucky(self, n): 
+        #RETURN True OR False
+        return self.lucky(n,2)
+
+# Driver Code Starts
+if __name__ == '__main__':
+    t=int(input())
+
+    for tcs in range(t):
+        n=int(input())
+        obj = Solution()
+        if obj.isLucky(n):
+            print(1)
+        else:
+            print(0)
+
+# } Driver Code Ends

Recursion/subsequence_recursion.py

@@ -0,0 +1,16 @@
+def get_all_subsequence(n,output,i):       
+    if (i==len(n)):
+        if (len(output)!=0):
+            print(output)
+    else:
+        # exclude first character
+        get_all_subsequence(n,output,i+1)
+
+        # include first character
+        output+=n[i]
+        get_all_subsequence(n,output,i+1)
+    return
+
+n = input()
+get_all_subsequence(n,"",0)
+print(n[0])