def compute_block_key(path, index, length=2):
    """
    Computes a block key from a file path and an index.
    Args:
        path(str): Path to the file related to the blocloggerk
        index(int): index of the block
        length(int, optional): Length of the index part of the key for zero filling (Defaults to 2)
    Returns:
        str: Block key
    """
    return path + "-" + str(index).zfill(length)