Swap key and value of a dictionary - and sort it

[DeaD_EyE]

It was just the wrong index. Use index 0 if you want to sort by keys and if you use 1, you're sorting by values.

If you sort by keys, you should get this order:

In [45]: sorted("precise clever talented bright smart exact".split())
Out[45]: ['bright', 'clever', 'exact', 'precise', 'smart', 'talented']

For example, you can sort your str also by length:

In [46]: sorted("precise clever talented bright smart exact".split(), key=len)
Out[46]: ['smart', 'exact', 'clever', 'bright', 'precise', 'talented']

Now back to your code:

def reverse_dictionary(input_dict):
    my_dict= {}
    for key, value in input_dict.items():
        for string in value:
            my_dict.setdefault(string.lower(), []).append(key.lower())
    output_dict={k:v for k,v in sorted(my_dict.items(), key=lambda item:item[0])} # not index 1, index 0 is the key
    return output_dict


# first iteration
from operator import itemgetter


def reverse_dictionary(input_dict):
    result = {}
    by_key = itemgetter(0)
    for key, values in input_dict.items():
        for string in values:
            result.setdefault(string.lower(), []).append(key.lower())
    return dict(sorted(result.items(), key=by_key))


# second iteration
from collections import defaultdict
from operator import itemgetter


def reverse_dictionary(input_dict):
    result = defaultdict(list)
    by_key = itemgetter(0)
    for key, values in input_dict.items():
        for string in values:
            result[string.lower()].append(key.lower())
    return dict(sorted(result.items(), key=by_key))


# third iteration
from collections import defaultdict
from operator import itemgetter


def sort_dict_keys(mapping):
    return dict(sorted(result.items(), key=itemgetter(0)))


def reverse_dictionary(input_dict):
    result = defaultdict(list)
    for key, values in input_dict.items():
        for string in values:
            result[string.lower()].append(key.lower())
    return sort_dict_keys(result)

If you have a predefined order, you could use a mapping to int.
Predefined order:

def custom_order(key_value, default=0):
    key, _ = key_value
    key_order = {
        "bright": 1,
        "clever": 2,
        "exact": 100,
        "precise": 3,
        "smart": 4,
        "talented": 5,
    }
    return key_order.get(key, default)

It's not the best example because the dict was defined inside the function.
But I hope it helps to clarify that you can do also custom sort order.