python classmethod

class MyClass(object):
  def __init__(self, x):
    self.x = x

class Person:
  def __init__(self, name, age):
    self.name = name
    self.age = age

p1 = Person("John", 36)

p1.age = 40

print(p1.age)
---------------------------------------------------------------
40

class Person:#set name of class to call it 
  def __init__(self, name, age):#func set ver
    self.name = name#set name
    self.age = age#set age
   

    def myfunc(self):#func inside of class 
      print("Hello my name is " + self.name)# code that the func dose

p1 = Person("barry", 50)# setting a ver fo rthe class 
p1.myfunc() #call the func and whitch ver you want it to be with 

class Dog(object):
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def speak(self):
        print("Hi I'm ", self.name, 'and I am', self.age, 'Years Old')

JUB0T = Dog('JUB0T', 55)
Friend = Dog('Doge', 10)
JUB0T.speak()
Friend.speak()

# Python program to 
# demonstrate instantiating 
# a class 
  
  
class Dog:  
      
    # A simple class 
    # attribute 
    attr1 = "mamal"
    attr2 = "dog"
  
    # A sample method   
    def fun(self):  
        print("I'm a", self.attr1) 
        print("I'm a", self.attr2) 
  
# Driver code 
# Object instantiation 
Rodger = Dog() 
  
# Accessing class attributes 
# and method through objects 
print(Rodger.attr1) 
Rodger.fun() 

class Animal(object): # Doesn't need params but put it there anyways.
    def __init__(self, species, price):
        self.species = species # Sets species name
        self.price = price # Sets price of it
    
    def overview(self): # A function that uses the params of the __init__ function
        print(f"This species is called a {self.species} and the price for it is {self.price}")

class Fish(Animal): # Inherits from Animal
    pass # Don't need to add anything because it's inherited everything from Animal
 
salmon = Fish("Salmon", "$20") # Make a object from class Fish
salmon.overview() # Run a function with it
dog = Animal("Golden retriever", "$400") # Make a object from class Animal
dog.overview() # Run a function with it

class Float:
    def __init__(self, amount):
        self.amount = amount

    def __repr__(self):
        return f'<Float {self.amount:.3f}>'

    @classmethod
    def from_sum(cls, value_1, value_2):
        return cls(value_1 + value_2)


class Dollar(Float):
    def __init__(self, amount):
        super().__init__(amount)
        self.symbol = '€'

    def __repr__(self):
        return f'<Euro {self.symbol}{self.amount:.2f}>'


print(Dollar.from_sum(1.34653, 2.49573)) 

# Python CLASSMETHOD 
  
class Subject: 
      
    # create a variable 
    favorite_subject = "Networking"
      
    # create a function 
    def favorite_subject_name(obj): 
        print("My favorite_subject_name is : ", 
                           obj.favorite_subject) 
          
# create favorite_subject_name classmethod 
# before creating this line favorite_subject_name() 
# It can be called only with object not with class 
Subject.favorite_subject_name = classmethod(Subject.favorite_subject_name) 
  
# now this method can be called as classmethod 
# favorite_subject_name() method is called as class method 
Subject.favorite_subject_name() 

>>> class Snake:
...     pass
... 
>>> snake = Snake()
>>> print(snake)
<__main__.Snake object at 0x7f315c573550>

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)