>>> from datetime import datetime
>>> ts = int("1284101485")

# if you encounter a "year is out of range" error the timestamp
# may be in milliseconds, try `ts /= 1000` in that case
>>> print(datetime.utcfromtimestamp(ts).strftime('%Y-%m-%d %H:%M:%S'))
#'%Y' will be replaced by the year '%m' by the month '%d; by the day and so on 
#You move these how you want in the string, other characters will be ignored!
... '2010-09-10 06:51:25'