Richie Hindle schrieb: > [Stephen] > >>[...] compare 2 lists and generate a new list that does not copy similar >>entries. An example below >> >>list= ["apple", "banana", "grape"] >>list2=["orange","banana", "pear"] >> >>now I want to compare these lits and generate a third list after >>comparison >> >>list3 would be ["apple", "banana","grape","orange", "pear"] > > > Use sets: > > >>>>from sets import Set as set # For compatibility with Python 2.3 >>>>one = ["apple", "banana", "grape"] >>>>two = ["orange","banana", "pear"] >>>>print list(set(one) | set(two)) > > ['grape', 'apple', 'orange', 'pear', 'banana'] >
Why using Set two times, when you can do it with one call? >>> list(set(one + two)) According to my benchmarks, this was five times faster than calling it twice and use |. There are also a few more good approaches uniquifying lists at http://www.peterbe.com/plog/uniqifiers-benchmark Regards, Stargaming -- http://mail.python.org/mailman/listinfo/python-list
