Do Notation using Python's Yield Keyword

do_notation.py

from functools import wraps


def do(f):
    def partial_run(f, args, kwargs, values_so_far=()):
        # First, create a NEW instance of the coroutine.
        coroutine = f(*args, **kwargs)

        # Advance the coroutine to the first yield point.
        yielded_monad = next(coroutine)

        # For each value so far, send it into the coroutine.
        for v in values_so_far:
            try:
                yielded_monad = coroutine.send(v)
            except StopIteration as ret:
                # This means we've reached the end of the function;
                # lift the return value back into the monad.
                return yielded_monad.point(ret.value)

        def continue_with_value(value):
            """Continue the coroutine execution, pre-filling a given value."""
            return partial_run(f, args, kwargs, (*values_so_far, value))

        return yielded_monad >> continue_with_value

    @wraps
    def wrapped(*args, **kwargs):
        return partial_run(f, args, kwargs)

    return wrapped