importmath importpandasaspd importcsv fromtqdmimporttqdm defmask(x): ifnotx.cls1: returnx else: ifpd.isna(x.cls4): returnx else: ifx.cls4.find('')-1: x.cls1=x.cls4 returnx else: words=x.cls4.split() x.cls1=words[0] x.cls2=words[1] returnx df=pd.read_csv("./2000qV15.txt",sep='\t',encodin...