cubicweb-timeseries #1707104 [entities] refactor entities.py for better modularity [resolved]

Turning it into a package (it is getting huge).

Transform the grok_data and _to_numpy methods into proper adapters (will make handling of various time series types quite easier).

prioritynormal
typeenhancement
done in1.1.1
load0.600
load left0.000
closed by<not specified>