39-method-overloading-3.py

#!/usr/bin/env python

# 39-method-overloading-3.py

# We've seen that inherited methods can be overloaded.
# This is possible using in-built functions as well.

# Let's see how we can overload methods from the `list` module.


class MyList(list):

    def __getitem__(self, index):
        if index == 0:
            raise IndexError
        if index > 0:
            index -= 1
        return list.__getitem__(self, index)

    def __setitem__(self, index, value):
        if index == 0:
            raise IndexError
        if index > 0:
            index -= 1
        list.__setitem__(self, index, value)

x = MyList(['a', 'b', 'c'])
print(x)
print("-" * 10)

x.append('d')
print(x)
print("-" * 10)

x.__setitem__(4, 'e')
print(x)
print("-" * 10)

print(x[1])
print(x.__getitem__(1))
print("-" * 10)

print(x[4])
print(x.__getitem__(4))