Creating 2D dictionary in Python

Question

I have a list of details from an output for "set1" which are like "name", "place", "animal", "thing" and a "set2" with the same details.

I want to create a dictionary with dict_names[setx]['name']... etc On these lines.

Is that the best way to do it? If not how do I do it?

I am not sure how 2D works in dictionary.. Any pointers?

Legitimize

It would help to give a more specific and complete example. What's in setx, and what do you want dict_names[setx]['name'] to return? – Continuate

Answer 1

It would have the following syntax

dict_names = {
    'd1': {
        'name': 'bob',
        'place': 'lawn',
        'animal': 'man'
    },
    'd2': {
        'name': 'spot',
        'place': 'bed',
        'animal': 'dog'
    }
}

You can then look things up like

>>> dict_names['d1']['name']
'bob'

To assign a new inner dict

dict_names['d1'] = {'name': 'bob', 'place': 'lawn', 'animal': 'man'}

To assign a specific value to an inner dict

dict_names['d1']['name'] = 'fred'

Shatzer

I have {'name':'bob', 'place':'lawn', 'animal':'man'} part created but how do I assign it as key to d1? – Legitimize

dict_names['d1'] = {'name':'bob', 'place':'lawn', 'animal':'man'} – Shatzer

so this is like a regular 1D dictionary. – Legitimize

Sorry - i followed the entire thing. Just took me a few minutes, oddly even though i understand the dictionary concept clearly. The big structures kind of scare me I think! – Legitimize

How about the case when I need to get the top-level both by the first and second key - for instance, pull all the objects that have a "name" tag in them? – Retroflexion

Good answer! Is there a way we could do the above in a for loop; i.e. say there're k number of dictionaries with the same keys but different features. I'd like to combine them into a 2d dictionary in a for loop. I've tried initializing an empty dictionary and append. But that didn't work. Any help would be appreciated! – Eastereasterday

Answer 2

Something like this would work:

set1 = {
     'name': 'Michael',
     'place': 'London',
     ...
     }
# same for set2

d = dict()
d['set1'] = set1
d['set2'] = set2

Then you can do:

d['set1']['name']

etc. It is better to think about it as a nested structure (instead of a 2D matrix):

{
 'set1': {
         'name': 'Michael',
         'place': 'London',
         ...
         }
 'set2': {
         'name': 'Michael',
         'place': 'London',
         ...
         }
}

Take a look here for an easy way to visualize nested dictionaries.

Ropedancer

this saves the repeated values – Tingaling

Answer 3

Something like this should work.

dictionary = dict()
dictionary[1] = dict()
dictionary[1][1] = 3
print(dictionary[1][1])

You can extend it to higher dimensions as well.

Ur

Answer 4

If I understand your question properly, what you need here is a nested dictionary.You can use the addict module to create nested dictionaries quite easily. https://github.com/mewwts/addict

if the items in each set is ordered, you could use the below approach

 body = Dict()
    setx = ['person1','berlin','cat']
    sety = ['person2','jena','dog']
    setz = ['person3','leipzig','tiger']
    for set_,s in zip([setx,sety,setz],['x','y','z']):
        for item,item_identifier in zip(set_,['name','city','animmal']):
            body[f'set{s}'][f'{item_identifier}'] = item

now you can easily access the items as follows.

print(body['setx']['name'])

Runny

Answer 5

Simple one-liner for a nested 2D dictionary ( dict_names = {} ) :

dict_names.setdefault('KeyX',{})['KeyY']='Value'

Agrobiology