How to select keys from a dictionary by their order?

Question

Sorry this is probably very simple, but I suspect I'm wording the question wrong from inexperience so I haven't been able to find the answer anywhere.

I have a dictionary, e.g.:

dict = {1: 'a', 2: 'b'}

I want to select specific values within the dictionary from knowing only their position in the dictionary.

For example I want to print the first key, and all I know about the key is that it's the first key in the dictionary, not its actual name to call on.

I am trying:

dict[0][0]

And I'm expecting this to output 1, the first key in the dictionary - but I'm not experienced in python so I'm not sure how to get this working?

Depending on your python version, the dictionary may or may not be ordered by insertion order. I think it is guaranteed for python 3.7+ and accidentally the case for 3.5&3.6. Dictionaries don't support direct indexing though — PirateNinjas, May 07 '21 at 10:16
Indexing was the word I needed to know to do a much better job googling this problem - thank you for this!! Good to know I can't do it directly so I can try something else, thanks! — DN1, May 07 '21 at 10:19

score 1 · Accepted Answer · answered May 07 '21 at 10:17

1

This is probably what you were looking for.

Note this is for Python 3.7 and forward.

d = {1: 'a', 2: 'b'} # dict is a bad variable name! don't do it! it overrides a built-in!
d_keys = list(d.keys())
first_value = d[d_keys[0]]

answered May 07 '21 at 10:17

Gulzar

23,452
27
113
201

1

Thank you for this, didn't realise about the dict thing either - will keep that in mind going forward, thanks! – DN1 May 07 '21 at 10:32

score 1 · Answer 2 · answered May 07 '21 at 10:18

Dictionaries cannot be used like lists, in that you cannot refer to their position. However, you can use something like this to get the keys from your dictionary:

my_dict = {1: 'a', 2: 'b'}

for k in my_dict:
    print(k)
    print(my_dict[k])

Output:

1
a
2
b

score 1 · Answer 3 · answered May 07 '21 at 10:18

1

Try to get all keys by keys() method then take first key which is 1 this:

dict = {1: 'a', 2: 'b'}
keys = list(dict.keys())
print(keys[0]) #1

answered May 07 '21 at 10:18

XMehdi01

5,538
2
10
34

score 1 · Answer 4 · answered May 07 '21 at 10:28

There's not any builtin method to access key or values within a dictionary via indexes. But you can achieve your desired outcome by converting the dictionary to list of list via list comprehension.

dictt = {1: 'a', 2: 'b'}
dict_items = [[k,v] for k,v in dictt.items()]
print(dict_items)
>> [[1, 'a'], [2, 'b']]

If you want first key in the dictionary

print(dict_items[0][0])
>> 1

If you want first value in the dictionary

print(dict_items[0][1])
>> a

If you want second key in the dictionary

print(dict_items[1][0])
>> 2

If you want second value in the dictionary

print(dict_items[1][1])
>> b

How to select keys from a dictionary by their order?

4 Answers4