Is it possible to sort this kind of dictionaries:

1. First by rank
2. If rank is the same then sort by first element in other_ranks list
3. If first element in other_ranks is the same - go deeper until last element in list.

If this is a trouble, I can make this dictionary structurized in different way.

{'rank': 6, 'other_ranks': [7, 5]}
{'rank': 1, 'other_ranks': [7, 11, 6, 2]}
{'rank': 0, 'other_ranks': [12]}
{'rank': 1, 'other_ranks': [13, 11, 4, 3]}
{'rank': 1, 'other_ranks': [14, 12, 6, 5]}
{'rank': 4, 'other_ranks': [5, 4, 3, 2]}
{'rank': 0, 'other_ranks': [12]}

CodePudding user response：

Assuming a list, you can use operator.itemgetter in conjunction with the key argument of sorted:

from operator import itemgetter

lst = [{'rank': 6, 'other_ranks': [7, 5]},
       {'rank': 1, 'other_ranks': [7, 11, 6, 2]},
       {'rank': 0, 'other_ranks': [12]},
       {'rank': 1, 'other_ranks': [13, 11, 4, 3]},
       {'rank': 1, 'other_ranks': [14, 12, 6, 5]},
       {'rank': 4, 'other_ranks': [5, 4, 3, 2]},
       {'rank': 0, 'other_ranks': [12]}]


res = sorted(lst, key=itemgetter("rank", "other_ranks"))
print(res)

Output

[{'other_ranks': [12], 'rank': 0},
 {'other_ranks': [12], 'rank': 0},
 {'other_ranks': [7, 11, 6, 2], 'rank': 1},
 {'other_ranks': [13, 11, 4, 3], 'rank': 1},
 {'other_ranks': [14, 12, 6, 5], 'rank': 1},
 {'other_ranks': [5, 4, 3, 2], 'rank': 4},
 {'other_ranks': [7, 5], 'rank': 6}]

The key here is that list and tuples are compared lexicographically, from the documentation:

Sequences of the same type also support comparisons. In particular, tuples and lists are compared lexicographically by comparing corresponding elements.

Therefore just compare them as is.

CodePudding user response：

That's called lexigraphical comparison. Python's tuples implement that.

dictionaries = [
    {'rank': 6, 'other_ranks': [7, 5]},
    {'rank': 1, 'other_ranks': [7, 11, 6, 2]},
    {'rank': 0, 'other_ranks': [12]},
    {'rank': 1, 'other_ranks': [13, 11, 4, 3]},
    {'rank': 1, 'other_ranks': [14, 12, 6, 5]},
    {'rank': 4, 'other_ranks': [5, 4, 3, 2]},
    {'rank': 0, 'other_ranks': [12]},
]
dictionaries.sort(key=lambda dict_: (dict_['rank'], )   tuple(dict_['other_ranks']))