Develop

I found a problem that if I use the command of "cat" for a txt file,then each row of the contents will be added one more blank line,which means if there are only five rows contents in the original text file,you will print ten rows contents containing five additional blank rows.I think the reason is each row contains a "\n" in the end and you also add another "\n" ,thus it will print  "\n" twice.
Therefore,I modify the utilities.py to judge if the line contains a '\n' in the end  and then process it in different way.