Aggregates Operation Syntax

Hey,
I would like to aggregate data from the gnocchi database by using the gnocchi aggregates function of the CLI/API
The documentation does not cover the operations that are available nor the syntax that has to be used:
https://gnocchi.xyz/gnocchiclient/shell.html?highlight=reaggregation#aggregates

Searching for more information I found a GitHub Issue:
https://github.com/gnocchixyz/gnocchi/issues/393
But I cannot use the syntax from that ether.

My use case:
I want to aggregate the vcpus hours per month, vram hours per month, … per server or project.
- when an instance is stopped only storage is counted
- the exact usage is used e.g. 2 vcpus between 1st and 7th day 4vcpus between 8th and last month no mean calculations

Do you have detailed documentation about the gnocchi Aggregates Operation Syntax?
Do you have complex examples for gnocchi aggregations? Especially when using the python bindings:
conn_gnocchi.metric.aggregation(metrics="memory", query=[XXXXXXXX], resource_type='instance', groupby='original_resource_id')
Can you give me advice regarding my use case? Do's and don'ts…

Thank you for your help in advance!
Merlin Blom