UPDATE FUNCTION "my_func"
FROM FILE "1.py"
REPLACE WHOLE WITH CASE
WHEN REGEX r'''# Some comment''' THEN SUB
r'''# Some comment\n.*?something = find[search["col1"].isna()]'''
r'''# Some comment (and then some)
elements_type_2 = search[search["something"].isna()]
elements_type_1 = elements_type_2[elements_type_2["req"].isna()]'''
END;

instead,:

UPDATE FUNCTION "my_func"
FROM FILE "1.py"
REPLACE LINE REGEX r'''# Some comment''' WITH CONTENTS '''

elements_type_2 = search[search["something"].isna()]
elements_type_1 = elements_type_2[elements_type_2["req"].isna()]'''
''';