$re = '/class\s(\w+)|def\s(\w+)/m';
$str = 'class MyClass_1(...):
...
def method1_of_first_class(self):
...
def method2_of_first_class(self):
...
def method3_of_first_class(self):
...
class MyClass_2(...):
...
def method1_of_second_class(self):
...
def method2_of_second_class(self):
...
def method3_of_second_class(self):
...';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php