Completed "Methods" exercises.

Author: anosidium

prep exercises/Methods exercise 1

@@ -0,0 +1,4 @@
+The advantage of a method as a opposed to freestanding function is that it works on the instance of a type.
+The freestanding function knows nothing about the instance of the type because it doesn't belong to a type.
+On an instance, the method can influence the internal states.
+However freestanding function can only work on public APIs whereas instance methods have access to internal APIs.

prep exercises/Methods exercise 2.py

@@ -0,0 +1,19 @@
+from datetime import date
+
+class Person:
+    def __init__(self, name: str, date_of_birth: date, preferred_operating_system: str):
+        self.name = name
+        self.date_of_birth = date_of_birth
+        self.preferred_operating_system = preferred_operating_system
+
+    def is_adult(self):
+        today = date.today()
+        age = today.year - self.date_of_birth.year
+
+        if (today.month, today.day) < (self.date_of_birth.month, self.date_of_birth.day):
+            age -= 1
+
+        return age >= 18
+
+imran = Person("Imran", date(2004, 6, 28), "Ubuntu")
+print(imran.is_adult())