I have a simple record structure consisting of a header (H) and a list of the data lines (D) 1:N. All header lines must start with a digit. All data lines have a leading whitespace. There also might be some empty lines (E) in between that must be ignored. L = [H, D, D, E, H, D, E, H, D, D, D]. I would like to create a list of records: -record(posting,{header,data}). using list comprehension. Whats the best way to do it?