A frozen list implementation.

list_04_frozen.py

from collections.abc import Iterable
from collections import UserList


def immutable_decorator(f):
    def wrapper(self, *args, **kwargs):
        raise TypeError("Object is frozen")
    return wrapper


class FrozenList(UserList):  # pylint: disable=too-many-ancestors
    """
    A List which is immutable.

    >>> fl: FrozenList = FrozenList("hello")
    >>> fl:FrozenList = FrozenList([1, 2, 4])
    >>> print(fl[1:2])
    [2]
    >>> print(fl)
    [1, 2, 4]
    >>> fl.append(1)
    Traceback (most recent call last):
     ...
    TypeError: Object is frozen
    >>> fl.extend(1)
    Traceback (most recent call last):
     ...
    TypeError: Object is frozen
    """
    @immutable_decorator
    def __setitem__(self, i: int, o) -> None:
        pass

    @immutable_decorator
    def __add__(self, other):
        pass

    @immutable_decorator
    def __iadd__(self, other):
        pass

    @immutable_decorator
    def __mul__(self, n: int):
        pass

    @immutable_decorator
    def __imul__(self, n: int):
        pass

    @immutable_decorator
    def append(self, item) -> None:
        pass

    @immutable_decorator
    def insert(self, i: int, item) -> None:
        pass

    @immutable_decorator
    def pop(self, i: int):
        pass

    @immutable_decorator
    def remove(self, item) -> None:
        pass

    @immutable_decorator
    def clear(self) -> None:
        pass

    @immutable_decorator
    def reverse(self) -> None:
        pass

    @immutable_decorator
    def extend(self, other) -> None:
        pass


l: list = [1, 2, 4]
fl: FrozenList = FrozenList(l)
assert fl[1:2] == [2]
fl: FrozenList = FrozenList("help")
assert fl[1::2] == ["e", "p"]