Datasource for screeners


I am trying to create screeners in ZERODHA PI and am facing some issues understanding what ‘Datasource’ values are to given while creating screeners. Searched for this in the tradescript documentation but that does not have any info on this.

The other issues I am facing is, when I run a screener on a set of say 100 stocks and when I ‘load’ the screener, it is showing all the 100 stocks irrespective of whether the stocks meet the screener rule or not. Is ‘loading’ a screener same as ‘running’ a screener?

Lot of people seem to be using screener in Pi. Can somebody who used it throw some light on where I can find detailed information on creating,executing and interpreting results of a screener.

Thanks in advance for your help