Esmail <ebo...@hotmail.com> writes: > Hello all, > > I wonder if someone could help me with sorting two corresponding lists. > > For instance the first list contains some items, and the second list > contains their value (higher is better) > > items = [apple, car, town, phone] > values = [5, 2, 7, 1] > > I would like to sort the 'items' list based on the 'values' list so > that I end up with the following two list: > > items = [town, apple, car, phone] > values = [7, 5, 2, 1] > > So I would like to keep the corresponding value still corresponding > after the sorting. > > Is there an easy/nice/Pythonic way to do this?
One way I have not seen in any reply is to sort the indices first. >>> values = [5, 2, 7, 1] >>> items = ['apple', 'car', 'town', 'phone'] Create a list of all indices: >>> indices = range(len(values)) >>> indices [0, 1, 2, 3] Sort the indices according to the value at each index: >>> indices.sort(key=lambda i: values[i], reverse=True) >>> indices [2, 0, 1, 3] Now you can get the sorted values and items without further sorting: >>> [values[i] for i in indices] [7, 5, 2, 1] >>> [items[i] for i in indices] ['town', 'apple', 'car', 'phone'] This can be spelt: >>> map(values.__getitem__, indices) [7, 5, 2, 1] >>> map(items.__getitem__, indices) ['town', 'apple', 'car', 'phone'] >>> HTH -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
