UPDATE: Thanks to @icews for helping me figure this out.  It turns out that the CAMEO Code field is saved as a string, but Pandas interprets that column as integers and drops the leading zero.  To read that column correctly, use the following line: data = pd.read_csv(/Data/ICEWS/events.2010.20150313084533.tab’, sep = ‘\t’, dtype={‘CAMEO Code’: object}) —————————————————————————————————————————————————— Wanting […]