added a code to reverse a strinf using stack

Author: manthansubhash01

Python/Reverse a String Using Stack.py

@@ -0,0 +1,18 @@
+class stack():
+    def __init__(self):
+        self.arr = []
+    def push(self,element):
+        self.arr.append(element)
+    def pop(self):
+        if self.size() != 0:
+            return self.arr.pop()
+    def size(self):
+        return len(self.arr)
+def reverse_string(s):
+    str_stack = stack()
+    reverse_str = ""
+    for i in s:
+        str_stack.push(i)
+    while str_stack.size() != 0:
+        reverse_str += str_stack.pop()
+    return reverse_str