Access revit element data - python revit api

Question

I'm a little confused about how you get access to Revit's element data, such as an element's parameters, location, Id, etc.. If I have this code:

collector = FilteredElementCollector(doc)
collector.OfCategory(BuiltInCategory.OST_Walls)
walls = collector.OfClass(FamilySymbol)
return walls

It will print: Autodesk.Revit.DB.FilteredElementCollector object at 0x0000000000000038 [Auto...]. Where do I go from here? For instance, How do I get a return of the walls' location?

There might be a lot in here, and multiple steps for each item. I am mainly looking for a general concept of getting and/or setting new element data.

Any thoughts?

Answer 1

I can't help with the Python, but I'm pretty familiar with Revit's API + C#.

You are using the collector to list all the walls on the project. What you want (to get the locations) is the FamilyInstance objects of these walls.

In C# would be something like this:

new FilteredElementCollector(uidoc.Document).OfClass(FamilyInstance).ToElements();

Next, you should loop the result to get each individual Element and convert it to a Wall:

foreach (Wall i in instances)
{
   var location = i.Location as LocationCurve;

   // The Curve element is a Line - 2 points defining it's position
   var p0 = location.Curve.GetEndPoint(0);
   var p1 = location.Curve.GetEndPoint(1);
}

Most of the information you want is on this FamilyInstance Object -> http://wikihelp.autodesk.com/Revit/enu/2014/Help/3665-Developers/0074-Revit_Ge74/0083-Family_I83/0086-FamilyIn86

Answer 2

The Revit API documentation points out that a FilteredElementCollector is an IEnumerable<Element>. So you actually have a list of wall objects. I like to add these to a python list to make working with them easier:

walls = list(collector)

Behind the scenes, list(collector) will do something like:

walls = []
for w in collector:
    walls.append(w)

(note, that this is not really how it works, but sort of explains it).

You can use the .NET inner workings to enumerate the walls in the collector by doing this:

enumerator = collector.GetEnumerator()
walls = []
while not enumerator.IsDone():
    walls.append(enumerator.Current)
    enumerator.MoveNext()

You will want to check if the collector.OfClass(FamilySymbol) line is correct - in my example document, that yielded an empty list - but maybe you do have walls that are FamilySymbols...

Next, you want to work with a wall object. So, take the first wall:

wall = walls[0]
interior_type_parameter = wall.Parameter['Interior Type']

And then work with the parameter... If you install the Revit SDK, you will find a tool for snooping objects and finding their parameters and values. Use this! Explore! Have fun!