import re


def valid_sql_in_clause_str(input_str):
    """Validates if input is comma separated, single quoted strings.

    Returns:
        True: valid
        False: Invalid

        For example:
        True: 
            "'1', '2345'"
            "'1'"
        False: 
            "1, 2345"
            "'abc', 'xyz'"
            ""
    """

    if not input_str:
        return False

    if re.search(r"^'(\d+)'(\s)*((\s)*(,)(\s)*('(\d+)'))*$", input_str):
        return True
    
    return False