get value from nested attribute by directly using element/attribute path

[sesambrein83]

Hi everyone,

is it possible to get asset framework values directly by using the path of the element and path like this?

\servername\ASD AF\R&D\Pilot Plants\H12\H12\H1|Oil Feed|Flow Control|PV

i could do it by explicitly doing this in code like this:

..but wouldn't it be neat if it could be done in one string?

[sesambrein83]

so for now i fixed it by splitting and looping. But there could be a more structured solution in the lib itself... maybe someone has a better idea?

`def getpointaverageAF(AFtag, startdatetime, enddatetime):

with PI.PIAFDatabase() as db:        
    if len(AFtag) > 20 and "|" in AFtag:
        splittag = AFtag.split('|')
        elem = db.descendant(splittag[0])            
        finaltag = elem.attributes[splittag[1]]
        if len(splittag) > 2:
            for x in range(len(splittag)-2):
                finaltag = finaltag.children[splittag[x+2]]
        result = finaltag.summary(startdatetime, enddatetime, SummaryType.AVERAGE).iloc[0]['AVERAGE']
    else:
        result = 'is not an AF Tag'
    return result

print(getpointaverageAF(r'R&D\Pilot Plants\H12\H12\H1|Oil Feed|Flow Control|PV', '12-12-2022 12:00:00', '12-12-2022 13:00:00'))

[Hugovdberg]

This is a nice addition that fits well with the way PIAFDatabase.descendant works. Just one question, is the | symbol also the official delimiter between attribute names or could that clash with valid attribute names?

[sesambrein83]

This is a nice addition that fits well with the way PIAFDatabase.descendant works. Just one question, is the | symbol also the official delimiter between attribute names or could that clash with valid attribute names?

Thanks Hugo, Yes it is. When you click copy path on an attribute in PI Asset Framework explorer it copies the path in an \element\element|attribute|attribute format

[Hugovdberg]

This has been added in the latest development version as PIAFDatabase.search(query: str|list[str]). It will probably be released this week in version 0.10.5

[sesambrein83]

Awesome thanks Hugo!

You might expect more features in the future. We are planning to use this plugin more at our production site.