Logic to allow logix_driver.write and .read to accept a list/tuple of (tag, value)

[gis667en11]

Hello! I made a quick modification to allow the write() method to accept an array of tuples.

if len(tags_values) == 1 and isinstance(tags_values[0], Union[tuple,list]):
. . . . tags_values = tags_values[0]

This going just before the "if len(tags_values) == 2" around line 1050. I'm not certain how to do pull requests, but this change allowed me to do things like this:

strings = [ 'tag.msgData.timeSinceLastReceipt_ms',
. . . . 'tag.msgData.timeSinceLastUpdate_ms',
. . . . 'tag.msgData.receiptCount',
. . . . 'tag.state_Start',
. . . . 'tag.state_Standby',
. . . . 'tag.coordinate_X',
. . . . 'tag.coordinate_Y']

svalues = [45, 555, 789, True, False, 3.14, 8008.135]

writeTags = zip(strings,svalues)

with pycomm3.LogixDriver('192.168.1.10') as plc:
. . . . plc.write(writeTags)

Or something fancy like this:

writeTags = []

if ButtonPressed:
. . . . buttonCount += 1
. . . . writeTags.extend( ('tag.ButtonCount', buttonCount) )

if updateTempAlarm:
. . . . if TemperatureHigh:
. . . . . . . . writeTags.extend( ('tag.tempAlarm', True)
. . . . else:
. . . . . . . . writeTags.extend( ('tag.tempAlarm', False)

if writeTags:
. . . . with pycomm3.LogixDriver('192.168.1.10') as plc:
. . . . . . . . plc.write(writeTags)

So, the write method would either write to the ButtonCount integer AND update the tempAlarm bool, OR just the tempAlarm bool, OR would write nothing at all.

With this method, the multi-service request feature of the write method can be leveraged while allowing a dynamic set of tags as an input. which is otherwise impossible with the current code.

The same is also possible by adding this to the .read() method:

if len(tags) == 1 and isinstance(tags[0], Union[tuple,list]):
. . . . tags = tags[0]

Or am I missing some trick for passing a variable number of arguments to a method?

[greggiles]

Try:

        if isinstance(x, list):
            test = plc.write(*x)
        elif isinstance(x,tuple):
            test = plc.write(x)

Using * on the argument of a list will unpack it.
Docs

[gis667en11]

Ah! This does work, thank you. Though, I think there's still value in adding the handler to pycomm3's base code to allow users the functionality without adding the if:else themselves. Thanks greg