def _append_query_filter(filterList, operator, left, right):
    """Append a query condition to a filter list.

    Args:
        filterList (list): List with query filters
        operator (string): operator to use
        left (object): Left-Hand value
        right (object): Right-Hand value

    Returns:
        list
    """
    if operator == '!=' or operator == '<>':
        filterList.append(left != right)
    elif operator == '==':
        filterList.append(left == right)
    elif operator == '>':
        filterList.append(left > right)
    elif operator == '<':
        filterList.append(left < right)
    elif operator == '>=':
        filterList.append(left >= right)
    elif operator == '<=':
        filterList.append(left <= right)

    return filterList