How can parse these file pattern in php?
You should try to use the parse_ini_file function of PHP (https://www.php.net/manual/en/function.parse-ini-file.php), available since PHP 4.
In your case:
$data = parse_ini_file("my_file.ini", true); // true to decode sections
/*
Result:
$data === [
'title1' => [
'delete_date' => '0101,0211,1115'
...
*/