Python accessing dictionary inside of dictionary returns distorted dict

Question

I have recently been working on a python application that handles some sort of schedule. I have a dictionary that contains the number of days in a rotation in a schedule, and then each day contains a dictionary with each different part of the day. It looks like this:

schedule = {
'rotation': 6,
'1' : {'B': '8:32', 'C': '9:34', 'D' : '10:36', 'F':'12:11', 'G': '1:13', 'H':'2:15'},

'2' : {'A': '8:32', 'B': '9:34', 'C,' : '10:36', 'E':'12:11', 'F': '1:13', 'G,':'2:15'},

'3' : {'A': '8:32', 'B': '9:34', 'D,' : '10:36', 'E':'12:11', 'F': '1:13', 'H,':'2:15'},

'4' : {'A': '8:32', 'C': '9:34', 'D,' : '10:36', 'E':'12:11', 'G': '1:13', 'H,':'2:15'},


'5' : {'B' : '8:40', 'D' : '11:00', 'F' : '12:55', 'H' : '2:15' },

'6' : {'A' : '8:40', 'C' : '11:00', 'E' : '12:55', 'G' : '2:15' }

}

This all looks like it should work, yet when I print it out, I get a distorted dictionary that looks like it is sorted:

{'1': {'C': '9:34', 'B': '8:32', 'D': '10:36', 'G': '1:13', 'F': '12:11', 'H': '2:15'}, 
'3': {'A': '8:32', 'D,': '10:36', 'B': '9:34', 'E': '12:11', 'F': '1:13', 'H,': '2:15'}, 
'2': {'A': '8:32', 'B': '9:34', 'E': '12:11', 'F': '1:13', 'C,': '10:36', 'G,': '2:15'}, 
'5': {'H': '2:15', 'B': '8:40', 'D': '11:00', 'F': '12:55'}, 
'4': {'A': '8:32', 'C': '9:34', 'E': '12:11', 'G': '1:13', 'D,': '10:36', 'H,': '2:15'}, 
'6': {'A': '8:40', 'C': '11:00', 'E': '12:55', 'G': '2:15'}, 
'rotation': 6}

As you can see, in day 1, it starts with C instead of B when printing, and the 'rotation' is at the end of the dictionary instead of the front. Why does my dictionary print like this?

Dictionaries are generally unordered. You can't expect your insertion order to be preserved. — user2390182, Oct 08 '18 at 14:58
This question could help https://stackoverflow.com/questions/11784860/why-does-this-python-dictionary-get-created-out-of-order-using-setdefault — Alex Ford, Oct 08 '18 at 14:58

score 1 · Accepted Answer · answered Oct 08 '18 at 14:58

1

The order in a dictionary is not stable, due to the hash function. On top of this, Python now uses a salt value when hashing, meaning that the order will be different each run (except if you ask for a stable dict).

answered Oct 08 '18 at 14:58

Matthieu Brucher

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Okay thank you, how would I tell the dictionary to be stable? – Nick D Oct 08 '18 at 15:01
Check python ordered dict on Google. – Matthieu Brucher Oct 08 '18 at 15:01

score 0 · Answer 2 · answered Oct 08 '18 at 15:10

0

Python dictionary is not required to preserve order. If order is what you want then you could use lists. If you just want to view a dictionary in sorted order, you can use .sort() or sorted() to help you print.

answered Oct 08 '18 at 15:10

Jake

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score 0 · Answer 3 · answered Oct 09 '18 at 18:01

You can sort this dictionary but you have to make an exception for rotation since its values do not fit the rest of the format of being a dictionary with alphabetical keys

d = {k: dict(sorted(v.items(), key=lambda x: x[0])) if k != 'rotation' else schedule[k] for k, v in schedule.items()}
print(d)
# {'rotation': 6, '1': {'B': '8:32', 'C': '9:34', 'D': '10:36', 'F': '12:11', 'G': '1:13', 'H': '2:15'}, '2': {'A': '8:32', 'B': '9:34', 'C,': '10:36', 'E': '12:11', 'F': '1:13', 'G,': '2:15'}, '3': {'A': '8:32', 'B': '9:34', 'D,': '10:36', 'E': '12:11', 'F': '1:13', 'H,': '2:15'}, '4': {'A': '8:32', 'C': '9:34', 'D,': '10:36', 'E': '12:11', 'G': '1:13', 'H,': '2:15'}, '5': {'B': '8:40', 'D': '11:00', 'F': '12:55', 'H': '2:15'}, '6': {'A': '8:40', 'C': '11:00', 'E': '12:55', 'G': '2:15'}}

Python accessing dictionary inside of dictionary returns distorted dict

3 Answers3