CODEWITHSUNDEEP
pythonsorting
Harry
Harry

Reputation: 13329

Python sort a list by two values

I'm trying to sort this list first by name in reverse. Then, after the first set of results (where flag = "ZAR"), I want to sort the remaining elements by time not in reverse:

import operator
list = [
    {"flag":"ZAR", "time":"17:45"},
    {"flag":"AUS", "time":"17:30"},
    {"flag":"AUS", "time":"17:15"},
    {"flag":"USA", "time":"17:00"},
    {"flag":"GBP", "time":"16:55"},
    {"flag":"ZAR", "time":"16:45"},
    {"flag":"USA", "time":"16:35"},
    {"flag":"GBP", "time":"16:25"},
    {"flag":"ZAR", "time":"16:15"},
]

list.sort(key=operator.itemgetter("time"))
list.sort(key=operator.itemgetter("flag"),reverse=True)


print list

[{'flag': 'ZAR', 'time': '16:15'}, {'flag': 'ZAR', 'time': '16:45'}, {'flag': 'ZAR', 'time': '17:45'}, {'flag': 'USA', 'time': '16:35'}, {'flag': 'USA', 'time': '17:00'}, {'flag': 'GBP', 'time': '16:25'}, {'flag': 'GBP', 'time': '16:55'}, {'flag': 'AUS', 'time': '17:15'}, {'flag': 'AUS', 'time': '17:30'}]

As you can see the flag sort was done correctly, but the other elements are only sorted by time within the sorted country.

What I want is to always have the ZAR first and after that it does not matter what the flag name is, only the time. So it should give this result:

[{'flag': 'ZAR', 'time': '16:15'}, {'flag': 'ZAR', 'time': '16:45'}, {'flag': 'ZAR', 'time': '17:45'}, {'flag': 'GBP', 'time': '16:25'}, {'flag': 'USA', 'time': '16:35'}, {'flag': 'GBP', 'time': '16:55'}, {'flag': 'USA', 'time': '17:00'}, {'flag': 'AUS', 'time': '17:15'}, {'flag': 'AUS', 'time': '17:30'}]

How would this be done?

Upvotes: 3

Views: 281

Answers (1)

Jon Clements
Jon Clements

Reputation: 142256

Amend your code to:

import operator
data = [
    {"flag":"ZAR", "time":"17:45"},
    {"flag":"AUS", "time":"17:15"},
    {"flag":"USA", "time":"17:00"},
    {"flag":"GBP", "time":"16:55"},
    {"flag":"ZAR", "time":"16:45"},
    {"flag":"USA", "time":"16:35"},
    {"flag":"GBP", "time":"16:25"},
    {"flag":"ZAR", "time":"16:15"},
]

data.sort(key=operator.itemgetter("time"))
data.sort(key=lambda L: L['flag'] == 'ZAR', reverse=True)

# [{'flag': 'ZAR', 'time': '16:15'}, {'flag': 'ZAR', 'time': '16:45'}, {'flag': 'ZAR', 'time': '17:45'}, {'flag': 'GBP', 'time': '16:25'}, {'flag': 'USA', 'time': '16:35'}, {'flag': 'GBP', 'time': '16:55'}, {'flag': 'USA', 'time': '17:00'}, {'flag': 'AUS', 'time': '17:15'}, {'flag': 'AUS', 'time': '17:30'}]

Upvotes: 5

Related Questions