diff --git a/Chapter05/Stack_using_array.py b/Chapter05/Stack_using_array.py
index 20ad138..f1c7f94 100644
--- a/Chapter05/Stack_using_array.py
+++ b/Chapter05/Stack_using_array.py
@@ -1,41 +1,40 @@
 size = 3
-data = [0]*(size)   #Initialize the stack
+data = [0] * (size)  # Initialize the stack
 top = -1
 
+
 def push(x):
-  global top
-  if top >= size-1:
-    print("Stack Overflow")
-  else:
-    top = top + 1
-    data[top] = x
+    global top
+    if top >= size - 1:
+        print("Stack Overflow")
+    else:
+        top = top + 1
+        data[top] = x
 
 
 def pop():
-  global top
-  if top == -1:
-    print("Stack Underflow")
-  else:
-    top = top-1
-    data[top] = 0
-    return data[top+1]
+    global top
+    if top == -1:
+        print("Stack Underflow")
+    else:
+        value = data[top]
+        data[top] = 0
+        top = top - 1
+        return value
 
 
 def peek():
-  global top
-  if top == -1:
-    print("Stack is empty")
-  else:
-    print(data[top])
-
-
+    if top == -1:
+        print("Stack is empty")
+    else:
+        print(data[top])
 
 
-push('egg')
-push('ham')
-push('spam')
-push('new')
-push('new2')
+push("egg")
+push("ham")
+push("spam")
+push("new")
+push("new2")
 
 print(data[0 : top + 1])
 
@@ -44,8 +43,8 @@ def peek():
 pop()
 pop()
 pop()
-print(data[0:top+1])
+print(data[0 : top + 1])
 
 peek()
 
-print(data[0:top+1])
+print(data[0 : top + 1])