Change 'Model Parameter' problem

[brad.bylls]

I am changing the values in the model parameters to be inches not metric.

The code below works for "setDistanceExtent" but not for "setSymmetricExtent"

I have been playing with the code but can't seem to figure it out.

    # Change to inches in Parameters

    extent_2 = adsk.fusion.DistanceExtentDefinition.cast(dowelODExt.extentOne)

    distanceMP_2 = adsk.fusion.ModelParameter.cast(extent_2.distance)   <<<<<<<< Line 191

    distanceMP_2.expression = "{:.{}f}".format(((numDowelLength * -1) / sizeUnits), 4) + 'in'

    dowelODExt.name = 'Dowel Length'

This is the error message I get:

[kandennti]

Hi @brad.bylls .

The extentOne property for symmetry is now a SymmetricExtentDefinition object instead of a DistanceExtentDefinition object.

The easiest way to deal with this would be to stop the casting.

        # extent_2 = adsk.fusion.DistanceExtentDefinition.cast(dowelODExt.extentOne)
        extent_2  = dowelODExt.extentOne
        distanceMP_2 = adsk.fusion.ModelParameter.cast(extent_2.distance)   #<<<<<<<< Line 191
        distanceMP_2.expression = "{:.{}f}".format(((numDowelLength * -1) / sizeUnits), 4) + 'in'
        dowelODExt.name = 'Dowel Length'

[brad.bylls]

What is casting?
And then what?
I took the original code from a sample script.

[kandennti · Accepted solution]

@brad.bylls .

There may be a better site, see here.

https://www.programiz.com/python-programming/type-conversion-and-casting 

In this case, type conversion is not possible, so None will be assigned as it is.

extent_2 = adsk.fusion.DistanceExtentDefinition.cast(dowelODExt.extentOne)

You can avoid the error by using this method.

extent_2  = dowelODExt.extentOne

[brad.bylls]

Thanks Kandennti.

It worked great once I shut down F360 and restarted it.