On Thu, Jul 30, 2020, 3:37 PM Marco Sulla <Marco.Sulla.Python@gmail.com> wrote:

On Thu, 30 Jul 2020 at 19:24, Steven D'Aprano <steve@pearwood.info> wrote:
You can't insert a key in a specific position. If I have this dict:

mydict = {'a': 1, 'c': 3, 'd': 4, 'e': 5}

I can't insert 'b':2 between keys 'a' and 'c', except by creating a new
dict.

Not sure about this. In C code, dicts are a hashtable and an array of items. In theory, nothing prevents you from inserting a new key in a specific position of the key array instead of at the end.

Nothing but the cost of shifting successive elements by 1 and sometimes copying the entire array to a new, larger array.

Would these be the *non-mutating* methods desired of insertion-ordered dicts?

.iloc[sli:ce]

.iloc[int]

.iloc[[list,]]

.iloc[callable]

.iloc[bitmask]

.index(key)

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