updated with new project structure.

app.py

+from scripts.services.main import shape
+
+shape()
\ No newline at end of file

scripts/constants/values.py

+PI = 3.14

shape/circle.py → scripts/core/handlers/circle.py

+from scripts.constants.values import PI
 # inherited Exception class
 class TestException(Exception):
     pass
@@ -9,7 +10,7 @@ class Circle:
 
     def area_circle(self):
         try:
-            area = 3.14 * self.radius * self.radius
+            area = PI * self.radius * self.radius
             return area
         except TestException:
             print("\nException Occurred\n")
@@ -18,7 +19,7 @@ class Circle:
 
     def perimeter_circle(self):
         try:
-            perimeter = 2 * 3.14 * self.radius
+            perimeter = 2 * PI * self.radius
             return perimeter
         except TestException:
             print("\nException Occurred\n")

main.py → scripts/services/main.py

 """import shapes from package 'shape'."""
-from shape.rectangle import Rect
-from shape.square import Square
-from shape.circle import Circle
+from scripts.core.handlers.rectangle import Rect
+from scripts.core.handlers.square import Square
+from scripts.core.handlers.circle import Circle
 
-# iterating variable
-i = 1
-while i == 1:
+def shape():
+    # iterating variable
+    i = 1
+    while i == 1:
         print("----------Area & Perimeter----------\n"
               "1.Rectangle\n"
               "2.Circle\n"
               "3.Square\n"
-          "4.Enter 0 to exit\n")
+              "4.Exit\n")
         choice = int(input("Enter the choice: "))
         if choice == 1:
             rect_length = float(input(
@@ -41,6 +42,6 @@ while i == 1:
                   square_inst.area_square())
             print("Perimeter of Square: ",
                   square_inst.perimeter_square())
-    elif choice == 0:
+        elif choice == 4:
             i = 0
-        # Exit if ch
+            # Exit if choice is 4