## Example: Here 'MyClass' defines some magic methods
# to add functionality behaviour to its instance
class MyClass:
  def __init__(self, a, b, c, d):
      self.some_id = a
      self.some_name = b
      self.some_age = c
      self.some_values = d

  # Define '__str__' to enable print functionality
  def __str__(self):
      """Add doc string to describe their behaviour"""
      return f"id: {self.some_id}, name: {self.some_name}"

  # Define '__len__' to enable showing length of 'MyClass' using
  # the 'len()' function
  def __len__(self):
      """Returns length of some_values"""
      return len(self.some_values)

  # Define '__getitem__' for enabling iteration/indexing/slicing of items
  def __getitem__(self, index):
      """Iterate through some_values"""
      return self.some_values[index]

  # Define '__call__' for making the instance callable
  def __call__(self, new_value):
      self.some_values.append(new_value)
      print(f"{new_value} was added")


## Create a instance to check these functionalities
my_instance = MyClass(239034, "Bob", 23, [10, 45, 32, 67, 32, 65])

# Print functionality, '__str__()' is invoked automatically
# when 'print()' is called on 'my_instance'
print(my_instance)  # id: 239034, name: Bob

# similarly length functionality, '__len__()' is invoked automatically
print(len(my_instance))  # 6

# Indexing and Slicing, '__getitem__()' is invoked
print(my_instance[0])  # 10
print(my_instance[0:3])  # [10, 45, 32]
# get all values using empty slice
print(my_instance[:])  # [10, 45, 32, 67, 32, 65]

# Iterating through the instance
for a in my_instance:
  print(a)  # 10 45 32 67 32 65

# Calling a instance,
my_instance(20)  # 20 was added
my_instance(90)  # 90 was added