def find_difference(left: dict, right: dict) -> dict:
    """Accepts two dicts with list values. Check which items are present in left
    but not in right, similar to set difference.

    Args:
        left (dict): Dict with list values
        right (dict): Dict with list values

    Returns:
        dict: Dict with list values. Contains items in left but not in right
    """
    diff = {} # Empty dict to store differences
    for key, values in left.items():
        if key in right.keys():
            right_values = [v for v in right[key]]
            diff[key] = set(values).difference(
                set(right_values)
            )
        else:
            # If key doesn't exist in right, all values are new
            diff[key] = left[key]
    
    diff = {k:v for k,v in diff.items() if len(v) > 0} # Remove empty
    return diff