Chaining in Python a la LangChain LCEL

operator_chain.py

from abc import ABC, abstractmethod


class Operator(ABC):
    @abstractmethod
    def __call__(self, *args, **kwargs):
        ...

    def __or__(self, other):
        class ChainedOperator(Operator):
            def __call__(_self, *args, **kwargs):
                return other(self(*args, **kwargs))

        return ChainedOperator()


class Add(Operator): 
    def __init__(self, value):
        self.value = value

    def __call__(self, x: int):
        return x + self.value


class Multiply(Operator):
    def __init__(self, value):
        self.value = value

    def __call__(self, y: int):
        return y * self.value


chain = Add(5) | Multiply(2) | Multiply(3)
output = chain(3)  # should return 48
print(output)