Equivalent data structure in python 3 of a complex structure in C++

Question

I want to create an equivalent data structure I used in a C++ assignment for python. I'm having trouble figuring out how to do this. The structure is given below -

 map < string, map < string, vector < int > > > invertedIndex;

Can you please point me in the right direction?

Edit : I know that list and dict are equivalents for vector and map respectively, I should have specified if there is a single line code in which I can initial this same data structure in python.

Exactly, do you want a ordered map, or just an unordered map? — user202729, Mar 31 '18 at 13:54
Possible duplicate of [Python equivalent for C++ STL vector/list containers](https://stackoverflow.com/questions/4637095/python-equivalent-for-c-stl-vector-list-containers) — Aran-Fey, Mar 31 '18 at 13:54
Dupe #2: https://stackoverflow.com/questions/3654770/is-there-a-structure-in-python-similar-to-c-stl-map — Aran-Fey, Mar 31 '18 at 13:54
Also please [format code](https://meta.stackoverflow.com/questions/251361/how-do-i-format-my-code-blocks). — user202729, Mar 31 '18 at 13:57
Python doesn't work like C++ does. You don't declare variables with types in the same way. This question is not really senseful. — Lightness Races in Orbit, Mar 31 '18 at 14:02
@user202729: Yes but not like C++'s. There is no one type to describe the given data structure like there is in C++. Python is not statically typed. — Lightness Races in Orbit, Mar 31 '18 at 14:05
There is no one type and that is the question, is there a way to replicate the functionality of the original ds using dict and list? — Ankit Srivastava, Mar 31 '18 at 14:06
Why on earth would any programming language have a single data structure that's exactly equivalent to `map>>`? _Of course_ you have to build that out of nested dicts and lists. — Aran-Fey, Mar 31 '18 at 14:13

score 0 · Accepted Answer · answered Mar 31 '18 at 14:30

Try defaultdict:

import collections, functools
inverted_index = collections.defaultdict(functools.partial(defaultdict, list))

Every dictionary key which doesn't exists will now automatically get created, although you are able to use any type unlike in the statically typed C++.

Equivalent data structure in python 3 of a complex structure in C++

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