How to use the same unit of measure in Revit and pyRevit?

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1

Hi everyone, I am moving my first steps in pyRevit. I am using a metric template within my file. I am getting flow value from the ducts selected in Revit using this script:

for el in selection:
if el.LookupParameter(‘Flow’):
print(el.LookupParameter(‘Flow’).AsDouble())

The values I obtain are different from the ones I can read in the properties palette, which are displayed in m^3/h. I tryed to solve the problem by using variables to convert the values directly inside pyRevit, but it is tricky because I have to pay attention every time I deal with numeric values. Another way I tryed is to obtain value .AsValueString(), and but I don’t think this is the best method, because in this case I obtain strings that report also the unit of measure. My question is: is there a way to use directly the same unit of measure automatically, to avoid undesired issues in my calculations?
Thank you in advice for your attention

2

AsValueString is probably the best method IMHO. converting in python, you might end up having rounding issues depending on the settings in revit.

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3

Thank you for your fast reply. Can I please ask how do you “clean” your string after you obtain it? I tryed list slicing, but I don’t think It is a good method because it depends on the number of charatcters I have to remove , that can be different every time I deal with different kind of parameters.

4 
yourlist  = ['84468 m²', '6468 m²', '64878 m²']

if you are trying to remove a space and get first item of your sliced list

x.split(' ')[0] for x in yourlist

or removing the same characters set over and over

x.split(' m²') for x in yourlist
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5

@Jean-Marc , do you have an excerpt of a script that shows how the “AsValueString” should be used?
I am trying to get an elevation of a level AsValueString but I keep getting errors.
Thank you!

6

and I forgot that one

    yourlist  = ['84468 m²', '6468 m²', '64878 m²']
    for x in yourlist:
        print (x[:-3])

or a slightly different flavor

print(list((x[:3]) for x in yourlist))
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7

something like this

Vals = []
for i in UnwrapElements([yourListOfRevitElements]]):
	Vals.append(i.LookupParameter("Type Id").AsValueString())

but there are a lot of examples all over the place:


or better

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where you will have code samples in C# most of the time but also in python for the most common methods and properties

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8

This isn’t a ‘smart’ fix but it’s worked for me in similar situations… Units default to imperial when using python (API or Dynamo python nodes) so I just convert the units to sqm by multiplying the double by the conversion factor. For example to get the sqm value:

area = el.LookupParameter(‘Flow’).AsDouble()
area = area * 10.76391041671

This table is handy for it: https://metricunitconversion.globefeed.com/area_conversion_table.asp

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9

Adding to the conversation, there is also the UnitFormatUtils as part of Revit API that allows all sorts of formatting conversions

See here :point_right: pyRevit/units.py at 92cb346eece706db810468984b3fa8564f14b16c · eirannejad/pyRevit · GitHub

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10

Thank you very much, it worked!
Here an example based on a walls selection:

param=selection[0].get_Parameter(BuiltInParameter.HOST_AREA_COMPUTED)
print(param.AsDouble())
pp = param.DisplayUnitType
print(pp)
number = UnitUtils.ConvertFromInternalUnits(param.AsDouble(), pp)
print (number)

Thank you again :slight_smile:

1 Like
11

Thank you so much @Jean-Marc ! very helpful!! :+1:

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