I need to access a dictionary in Python depending on a list. Example:
lst = ['A', 'B', 'C']
Then the dictionary accessing should be:
d['A']['B']['C']
The list can be of any depth/elements.
What is the best way to tackle this problem?
Asked
Active
Viewed 2,805 times
3
Mad Physicist
- 107,652
- 25
- 181
- 264
John
- 41
- 1
- 4
-
It would be very helpful if you could provide a example case of real input and expected output. – Vasilis G. Dec 19 '17 at 19:20
-
What do you want to do if one of the keys is missing? – Mad Physicist Dec 19 '17 at 19:29
2 Answers
2
I would create a function that iterates through the list:
d = {}
d['A'] = {}
d['A']['B'] = {}
d['A']['B']['C'] = 'value'
lst = ['A', 'B', 'C']
def get_value(d, lst):
for elem in lst:
d = d[elem]
return d
print get_value(d, lst) # outputs 'value'
francisco sollima
- 7,952
- 4
- 22
- 38
-
Why did you introduce a new variable instead of just rebinding `d`? – Mad Physicist Dec 19 '17 at 19:30
-
-
Is there a way to create a nested dictionary using the list? So if `lst = [ 'A', 'B', 'C']` then the dict created would be `d['A']['B']['C'] = {}` – John Dec 19 '17 at 19:37
-
@John. Why not try something yourself, even if it is just Googling? Your original question was closed as a duplicate, and I am pretty sure this new one is too. – Mad Physicist Dec 19 '17 at 19:38
2
One may also use the eval function applied to a string generated from the list:
eval('d[\''+'\'][\''.join(lst)+'\']')
here '\'][\'' is a delimiter
freude
- 3,632
- 3
- 32
- 51
-
-
My mistake. I did not read carefully. Downvote removed even though this is still bad advice. – Mad Physicist Dec 19 '17 at 19:32
-
what may be a better advice considering that we know nothing about the list and dictionary and how do they match together – freude Dec 19 '17 at 19:34
-