'What is the time complexity of adding new key-value pair to a dictionary in Python?

What's the time complexity of adding a new key-value pair like so:

d = dict()
d.update({'key':'value'})

Solution 1:^[1]

python dict is hash table

Below is table of "Time complexity in big O notation" (taken from the same link above)

Algorithm Average Worst case

Space O(n)1 O(n)

Search O(1) O(n)

Insert O(1) O(n)

Delete O(1) O(n)

Since "Set item" is listed as O(1) average case and O(n) worst case, I believe you can assume this is also the complexity for update().

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Solution	Source
Solution 1	balderman
Solution 2	Code-Apprentice