classes_staticandclassmethods.py

# -*- coding: utf-8 -*-
"""
Simply study related to  static and class methods

"""
import datetime


# First Example

class Warrior(object):

    # delta position - class variable
    delta_position = 10
    #number of warriors
    num_of_warriors = 0

    def __init__(self,posx,posy):
        self.posx = posx
        self.posy = posy

        Warrior.num_of_warriors+=1

    def move(self, posx,posy):
        self.posx = posx+ self.delta_position
        self.posy = posy +self.delta_position

    def position(self):
        return '{} , {}' .format(self.posx, self.posy)

# Second Example

class Monster(object):

    # delta position - class variable
    delta_position = 10
    #number of monters
    num_of_monsters = 0

    def __init__(self, posx, posy):
        self.posx = posx
        self.posy = posy

        Monster.num_of_monsters+= 1

    def move(self, posx,posy):
        self.posx = posx + self.delta_position
        self.posy = posy + self.delta_position

    def position(self):
        return '{} , {}' .format(self.posx,self.posy)

    # used to change the value of class variable
    # same as Monster.delta_position = new_value
    @classmethod
    def set_move(cls,inc):
        cls.delta_position = inc

    #using classmethod as alternatives consctructor
    @classmethod
    def from_str(cls, pos_str):
        posx, posy = pos_str.split("-")
        return cls(posx, posy)

        #static methods
    #behaves like a regular function
    @staticmethod
    def is_gameday(day):
        if day.weekday == 5 or day.weekday == 6:
            return False
        return True

if __name__ == "__main__":

    # First Example

    # declare an instance of Warrior Class
    Savage = Warrior(20, 10)
    Savage.move(10, 25)
    print(Savage.position())

    # print namespace of instance
    print(Savage.__dict__)

    # print namespace of class Warrior
    print(Warrior.__dict__)
    # print number of objects
    print(Warrior.num_of_warriors)

    # Second Example

    monster = Monster(30, 20)
    print(monster.position())
    # change value of class variable
    Monster.set_move(5)
    monster.move(10, 10)
    print(monster.position())

    # using the "alternative constructor"
    second_monster = Monster.from_str("10-30")
    print(second_monster.__dict__)

    # to test staticmethod
    now = datetime.datetime.now()
    print(Monster.is_gameday(now))