def parse_ranges_v1(range_string):
    """This version causes a memory error for huge ranges..."""
    ranges = [tuple(map(int, r.split("-"))) for r in range_string.split(",")]
    result = []
    for start, stop in ranges:
        result = [*result, *list(range(start, stop + 1))]
    for number in result:
        yield number


def parse_ranges_v2(range_string):
    """This version seems more memory efficient."""
    ranges = [tuple(map(int, r.split("-"))) for r in range_string.split(",")]
    for start, stop in ranges:
        for number in range(start, stop + 1):
            yield number


def parse_ranges_v3(range_string):
    """This version handles single digits, Bonus2."""
    ranges = [tuple(map(int, r.split("-"))) for r in range_string.split(",")]
    for limits in ranges:
        if len(limits) == 1:
            yield limits[0]
        else:
            start, stop = limits
            for number in range(start, stop + 1):
                yield number


def parse_ranges_v4(range_string):
    """My take at Bonus3."""
    # We prepare the data
    range_string = range_string.replace("->", "-")

    # We extract integer tuples from the data
    ranges = []
    for subrange in range_string.split(","):
        splited = subrange.split("-")
        try:
            item = tuple(map(int, splited))
        except ValueError:
            # This item shall then contains text in the 2nd part
            item = (int(splited[0]),)
        ranges.append(item)

    # We procede as before
    for limits in ranges:
        if len(limits) == 1:
            yield limits[0]
        else:
            start, stop = limits
            for number in range(start, stop + 1):
                yield number


parse_ranges = parse_ranges_v4