I found some helpful stuff on this site but my input file is different from the examples already posted and I cannot make the leap in an efficient manner. My input file looks like this: sample_dude data1 data2 data3 data4 sample_lady data5 data6 data7 data8 sample_dude data9 data10 data11 data12 sample_child data13 data14 data15 data16 I want to create a separate file for each sample with all the data columns. For example, one file would be called sample_dude.txt and look like this: data1 data2 data3 data4 data9 data10 data11 data12 There is an unknown number of samples but always just four data columns. Any help greatly appreciated. Thank you. PS: I'm trying to do this in python.