Update the sample code for the SOLID article (#709)

Co-authored-by: Bartosz Zaczyński <[email protected]>

Author: lpozo

solid-principles-python/README.md

@@ -1,3 +1,3 @@
-# SOLID Principles: Improve Object-Oriented Design in Python
+# SOLID Design Principles: Improve Object-Oriented Code in Python
 
-This folder provides the code examples for the Real Python tutorial [SOLID Principles: Improve Object-Oriented Design in Python](https://realpython.com/solid-principles-python/).
+This folder contains the code examples for the Real Python article [SOLID Design Principles: Improve Object-Oriented Code in Python](https://realpython.com/solid-principles-python/).

solid-principles-python/shapes_ocp.py

@@ -10,12 +10,16 @@
 #             self.height = kwargs["height"]
 #         elif self.shape_type == "circle":
 #             self.radius = kwargs["radius"]
+#         else:
+#             raise TypeError("Unsupported shape type")
 
 #     def calculate_area(self):
 #         if self.shape_type == "rectangle":
 #             return self.width * self.height
 #         elif self.shape_type == "circle":
 #             return pi * self.radius**2
+#         else:
+#             raise TypeError("Unsupported shape type")
 
 
 # Good example