クラスとオブジェクトを作成する

クラスとオブジェクトの作成

クラスとは

Pythonでのクラスの定義

class ClassName:
    def __init__(self, attribute1, attribute2):
        self.attribute1 = attribute1
        self.attribute2 = attribute2

    def method_name(self):
        # Code for the method
        pass

__init__ メソッド

# Defines the Person class with name and age attributes
class Person:
    def __init__(self, name, age):
        self.name = name  # Sets the name of the person
        self.age = age    # Sets the age of the person

クラスからのオブジェクトの作成

# Creates an object of the Person class
person1 = Person("Alice", 12)

# Accesses the object's attributes
print(person1.name)  # Output: Alice
print(person1.age)   # Output: 12

クラスへのメソッドの追加

# Defines the Person class with a greet method
class Person:
    def __init__(self, name, age):
        self.name = name  # Sets the name of the person
        self.age = age    # Sets the age of the person

    def greet(self):
        print("Hello, my name is " + self.name + "!")  # Prints a greeting message

# Creates an object of the Person class
person1 = Person("Bob", 15)

# Calls the greet method of the object
person1.greet()  # Output: Hello, my name is Bob!

プログラム例: シンプルなクラスの構築

# Defines the Car class
class Car:
    def __init__(self, make, model, color):
        self.make = make    # Sets the make of the car
        self.model = model  # Sets the model of the car
        self.color = color  # Sets the color of the car

    def display_info(self):
        print("Car Make:", self.make)    # Prints the make of the car
        print("Car Model:", self.model)  # Prints the model of the car
        print("Car Color:", self.color)  # Prints the color of the car

    def paint(self, new_color):
        self.color = new_color  # Changes the color of the car
        print("The car has been painted to", self.color)  # Confirms the color change

# Creates an object of the Car class
my_car = Car("Toyota", "Corolla", "Red")

# Calls the display_info method
my_car.display_info()
# Output:
# Car Make: Toyota
# Car Model: Corolla
# Car Color: Red

# Calls the paint method to change the car's color
my_car.paint("Blue")
# Output: The car has been painted to Blue

# Displays the updated car information
my_car.display_info()
# Output:
# Car Make: Toyota
# Car Model: Corolla
# Car Color: Blue

インスタンス変数とクラス変数

# Defines the Student class with a class variable
class Student:
    school = "XYZ High School"  # Class variable

    def __init__(self, name):
        self.name = name  # Instance variable

    def display_info(self):
        print(self.name + " attends " + Student.school)  # Prints student info

# Creates two objects of the Student class
student1 = Student("Alice")
student2 = Student("Bob")

# Calls the display_info method for both students
student1.display_info()
student2.display_info()

よくできました！