Add classes_and_objects_exercise2.py: demonstrate mypy type checking

- Create Person class with type-annotated __init__ method
- Add name (str), age (int), and preferred_operating_system (str) attributes
- Implement is_adult() function that correctly accesses Person.age attribute
- Add is_adult_wrong_attribute() function that intentionally accesses non-existent Person.address
- Demonstrate mypy error detection for invalid attribute access
- Show how mypy validates correct vs incorrect property references

Author: Iswanna

prep/classes_and_objects_exercise2.py

@@ -0,0 +1,22 @@
+class Person:
+    def __init__(self, name: str, age: int, preferred_operating_system: str):
+        self.name = name
+        self.age = age
+        self.preferred_operating_system = preferred_operating_system
+
+imran = Person("Imran", 22, "Ubuntu")
+print(imran.name)
+
+
+eliza = Person("Eliza", 34, "Arch Linux")
+print(eliza.name)
+
+def is_adult(person: Person) -> bool:
+    return person.age >= 18
+
+print(is_adult(imran))
+
+def is_adult_wrong_attribute(person: Person) -> bool:
+    return person.address
+
+print(is_adult_wrong_attribute(imran))