Sort a list of dictionaries…(Itemgetter)

I want to group a list of dictionaries by a key. The following code is working.

from itertools import groupby
from operator import itemgetter
user_dict = {123: [
                {'the_id': 1, 'title': 'Title1'},
                {'the_id': 1, 'title': 'Title1'},
                {'the_id': 3, 'title': 'Title3'},
                {'the_id': 2, 'title': 'Title2'}
]}

for user in user_dict:
    for id, value in groupby(user_dict[user], key=itemgetter('the_id')):
        titles = []
        for k in value:
            titles.append(k['title'])
        print(titles)

It results:

['Title1', 'Title1']
['Title3']
['Title2']

When I change the order in the dict, the "grouping" doesn’t work anymore.

from itertools import groupby
from operator import itemgetter
user_dict = {123: [
                {'the_id': 1, 'title': 'Title1'},
                {'the_id': 3, 'title': 'Title3'},
                {'the_id': 2, 'title': 'Title2'},
                {'the_id': 1, 'title': 'Title1'}
]}

for user in user_dict:
    for id, value in groupby(user_dict[user], key=itemgetter('the_id')):
        titles = []
        for k in value:
            titles.append(k['title'])
        print(titles)

This results to:

['Title1']
['Title3']
['Title2']
['Title1']

Can someone explain me that? How is the code correct?
Thanks.

>Solution :

You can sort the list of dictionaries before passing it to the groupby function to ensure grouping based on the 'the_id' key.

from itertools import groupby
from operator import itemgetter

user_dict = {123: [
                {'the_id': 1, 'title': 'Title1'},
                {'the_id': 3, 'title': 'Title3'},
                {'the_id': 2, 'title': 'Title2'},
                {'the_id': 1, 'title': 'Title1'}
]}

for user in user_dict:
    sorted_list = sorted(user_dict[user], key=itemgetter('the_id'))
    for id, value in groupby(sorted_list, key=itemgetter('the_id')):
        titles = []
        for k in value:
            titles.append(k['title'])
        print(titles)