## Example: Create a abstract class and inherit it
# import the 'ABC' class and 'abstractmethod' function from 'abc' module
from abc import ABC, abstractmethod

# inherit the 'ABC' class to create a abstract class
class MyBase(ABC):
  # define abstract methods by using 'abstractmethod' as decorator
  @abstractmethod
  def get_vars():
      pass

  @abstractmethod
  def change_values(self, a, b):
      pass

  # defining combination of method types
  # Notice: 'abstractmethod' should always follow later
  @staticmethod
  @abstractmethod
  def some_info():
      print("this method is both static and abstract")

  def mydefault_fun():
      print("This is normal method")


# Create concrete classes using 'MyBase' as parent class
class MyConcrete1(MyBase):
  def __init__(self, a, b):
      self.a = a
      self.b = b

  def change_values(self, a, b):
      self.a = a
      self.b = b

  def get_vars(self):
      return self.a, self.b

  def some_info(self):
      print(f"This is MyConcrete1")


# Creating another concrete class
class MyConcrete2(MyBase):
  def __init__(self, a, b, c):
      self.a = a
      self.b = b
      self.c = c

  def get_vars(self):
      return self.a, self.b, self.c


# Creating a instance of concrete classes
my_concrete1 = MyConcrete1(10, 20)
print(my_concrete1.get_vars())  # (10, 20)
my_concrete1.some_info()  # This is MyConcrete1


## Remember a concrete class has to implement all abstract methods
# of the abstract class, also note that 'mydefault_fun()' is not a
# method abstract, so it is not required to be defined, 'MyConcrete2'
# will raise 'TypeError' due to not implementing all abstract methods,
my_concrete2 = MyConcrete2(10, 20, 30)  # TypeError: Can't instantiate \
                                      # abstract class MyConcrete2 ...

# You cannot instantiate a abstract class
my_base = MyBase()  # TypeError: Can't instantiate abstract class MyBase ...