Sorting list based on values from another list Sorting list based on values from another list python python

# Sorting list based on values from another list

Shortest Code

``[x for _, x in sorted(zip(Y, X))]``

Example:

``X = ["a", "b", "c", "d", "e", "f", "g", "h", "i"]Y = [ 0,   1,   1,    0,   1,   2,   2,   0,   1]Z = [x for _,x in sorted(zip(Y,X))]print(Z)  # ["a", "d", "h", "b", "c", "e", "i", "f", "g"]``

Generally Speaking

``[x for _, x in sorted(zip(Y, X), key=lambda pair: pair[0])]``

Explained:

1. `zip` the two `list`s.
2. create a new, sorted `list` based on the `zip` using `sorted()`.
3. using a list comprehension extract the first elements of each pair from the sorted, zipped `list`.

For more information on how to set\use the `key` parameter as well as the `sorted` function in general, take a look at this.

Zip the two lists together, sort it, then take the parts you want:

``>>> yx = zip(Y, X)>>> yx[(0, 'a'), (1, 'b'), (1, 'c'), (0, 'd'), (1, 'e'), (2, 'f'), (2, 'g'), (0, 'h'), (1, 'i')]>>> yx.sort()>>> yx[(0, 'a'), (0, 'd'), (0, 'h'), (1, 'b'), (1, 'c'), (1, 'e'), (1, 'i'), (2, 'f'), (2, 'g')]>>> x_sorted = [x for y, x in yx]>>> x_sorted['a', 'd', 'h', 'b', 'c', 'e', 'i', 'f', 'g']``

Combine these together to get:

``[x for y, x in sorted(zip(Y, X))]``

Also, if you don't mind using numpy arrays (or in fact already are dealing with numpy arrays...), here is another nice solution:

``people = ['Jim', 'Pam', 'Micheal', 'Dwight']ages = [27, 25, 4, 9]import numpypeople = numpy.array(people)ages = numpy.array(ages)inds = ages.argsort()sortedPeople = people[inds]``

I found it here:http://scienceoss.com/sort-one-list-by-another-list/