def search(seq, key):
    """
    Takes a list of integers and searches if the `key` is contained within
    the list.

    :param seq: A list of integers
    :param key: The integer to be searched for
    :rtype: The index of where the `key` is located in the list. If `key` is
            not found then False is returned.
    """

    lo = 0
    hi = len(seq) - 1

    while hi >= lo:
        mid = lo + (hi - lo) // 2
        if seq[mid] < key:
            lo = mid + 1
        elif seq[mid] > key:
            hi = mid - 1
        else:
            # Returs the index
            return mid
    # Not found
    return None