Completed "Classes and objects" exercises.

Author: anosidium

prep exercises/Classes and objects exercise 1.py

@@ -0,0 +1,24 @@
+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)
+# print(imran.address) # error: "Person" has no attribute "address"  [attr-defined]
+
+eliza = Person("Eliza", 34, "Arch Linux")
+print(eliza.name)
+# print(eliza.address) # error: "Person" has no attribute "address"  [attr-defined]
+
+def is_adult(person: Person) -> bool:
+    return person.age >= 18
+
+print(is_adult(imran))
+
+def no_attribute_exists(person: Person):
+    print(person.dob)
+
+# mypy detects that dob attribute doesn't exist.
+# error: "Person" has no attribute "dob"  [attr-defined]