I'm using python 2.7.3, and I'm trying to sort a list of dictionaries based on the order of values of another list.
IE:
listOne = ['hazel', 'blue', 'green', 'brown']
listTwo = [{'name': 'Steve', 'eyecolor': 'hazel', 'height': '5 ft. 11 inches'},
{'name': 'Mark', 'eyecolor': 'brown', 'height': '6 ft. 2 inches'},
{'name': 'Mike', 'eyecolor': 'blue', 'height': '6 ft. 0 inches'},
{'name': 'Ryan', 'eyecolor': 'brown', 'height': '6 ft, 0 inches'},
{'name': 'Amy', 'eyecolor': 'green', 'height': '5 ft, 6 inches'}]
Sorting listTwo based off of the order of values in listOne, we would end up with the following:
print listTwo
[{'name': 'Steve', 'eyecolor': 'hazel', 'height': '5 ft. 11 inches'},
{'name': 'Mike', 'eyecolor': 'blue', 'height': '6 ft. 0 inches'},
{'name': 'Amy', 'eyecolor': 'green', 'height': '5 ft, 6 inches'},
{'name': 'Mark', 'eyecolor': 'brown', 'height': '6 ft. 2 inches'},
{'name': 'Ryan', 'eyecolor': 'brown', 'height': '6 ft, 0 inches'}]
I eventually need to output this text, so what I've done to display it correctly (in the correct order) is the following:
for x in xrange(len(listOne)):
for y in xrange(len(listTwo)):
if listOne[x] == listTwo[y]["eyecolor"]:
print "Name: " + str(listTwo[y]["name"]),
print "Eye Color: " + str(listTwo[y]["eyecolor"]),
print "Height: " + str(listTwo[y]["height"])
Is there some sort of lambda expression that can be used to make this happen? There has to be a more compact, less complex way of getting it in the order I want.
The simplest way would be to use list.index
to generate a sort value for your list of dictionaries:
listTwo.sort(key=lambda x: listOne.index(x["eyecolor"]))
This is a little bit inefficient though, since list.index
does a linear search through the eye-color list. If you had many eye colors to check against, it would be slow. A somewhat better approach would build an index dictionary instead:
order_dict = {color: index for index, color in enumerate(listOne)}
listTwo.sort(key=lambda x: order_dict[x["eyecolor"]])
If you don't want to modify listTwo
, you can use the built-in sorted
function instead of the list.sort
method. It returns a sorted copy of the list, rather than sorting in-place.
listOne = ['hazel', 'blue', 'green', 'brown']
listTwo = [{'name': 'Steve', 'eyecolor': 'hazel', 'height': '5 ft. 11 inches'},{'name': 'Mark', 'eyecolor': 'brown', 'height': '6 ft. 2 inches'},{'name': 'Mike', 'eyecolor': 'blue', 'height': '6 ft. 0 inches'},{'name': 'Ryan', 'eyecolor': 'brown', 'height': '6 ft, 0 inches'},{'name': 'Amy', 'eyecolor': 'green', 'height': '5 ft, 6 inches'}]
order_list_dict = {color: index for index, color in enumerate(listOne)}
print(order_list_dict)
print(sorted(listTwo, key=lambda i: order_list_dict[i["eyecolor"]]))
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.