how to use a class python code example

Example 1: how to make a class in python

class Person:
  def __init__(self, _name, _age):
    self.name = _name
    self.age = _age
   
  def sayHi(self):
    print('Hello, my name is ' + self.name + ' and I am ' + self.age + ' years old!')
    
p1 = Person('Bob', 25)
p1.sayHi() # Prints: Hello, my name is Bob and I am 25 years old!

Example 2: class in python

class ComplexNumber:
    def __init__(self, r=0, i=0):
        self.real = r
        self.imag = i

    def get_data(self):
        print(f'{self.real}+{self.imag}j')


# Create a new ComplexNumber object
num1 = ComplexNumber(2, 3)

# Call get_data() method
# Output: 2+3j
num1.get_data()

# Create another ComplexNumber object
# and create a new attribute 'attr'
num2 = ComplexNumber(5)
num2.attr = 10

# Output: (5, 0, 10)
print((num2.real, num2.imag, num2.attr))

# but c1 object doesn't have attribute 'attr'
# AttributeError: 'ComplexNumber' object has no attribute 'attr'
print(num1.attr)