ahmet / Python-for-Data-Science

def ft_filter(function, iterable) -> list:
    """filter(function or None, iterable) --> filter object

Return an iterator yielding those items of iterable for which function(item)
is true. If function is None, return the items that are true."""
    if function is None:
        return [item for item in iterable if item]
    return [item for item in iterable if function(item)]


def main() -> None:
    """Demonstrate ft_filter behaving like the built-in filter."""
    numbers = [1, 2, 3, 4, 5, 6, 7, 8]
    print(ft_filter(lambda n: n % 2 == 0, numbers))
    print(ft_filter(None, [0, 1, 2, "", "ok", None, "x"]))


if __name__ == "__main__":
    main()