non-stretch solution

python/queue.py

@@ -12,6 +12,8 @@ def enqueue(self, data):
 
   def dequeue(self):
     # write your code to removes the data to the Queue following FIFO and return the Queue
+    if not self.queue:
+      return 'Nothing to dequeue'
     self.queue.pop(0)
     self.total -= 1
     return self.queue

python/stack.py

@@ -1,14 +1,23 @@
 class Stack:
   # write your __init__ method here that should store a 'total' value which is the total number of elements in the Stack and a 'stack' value which is an array of stored values in the Stack
+  def __init__(self):
+    self.total = 0
+    self.stack = []
 
-  def push(self):
+  def push(self, data):
     # write your code to add data following LIFO and return the Stack
-    pass
+    self.stack.append(data)
+    self.total += 1
+    return self.stack
 
-  def pop(self, data):
+  def pop(self):
     # write your code to removes the data following LIFO and return the Stack
-    pass
+    if not self.stack:
+      return 'Nothing to pop'
+    self.stack.pop()
+    self.total -= 1
+    return self.stack
 
   def size(self):
     # write your code that returns the size of the Stack
-    pass
+    return self.total