Q:

How to get axis property with Revit API?

I am trying to used the Revit Interactive Python Shell to rotate an object in Revit. I am hung up on how to designate the axis of rotation. I don't know how to create a line with the API and then designate an axis in ElementTransformUtils.RotateElement()
The third argument in RotateElement() is the axis. I am creating a line but I am not sure if I am designating its axis in the third argument of .RotateElement()
When I run this code nothing happens. This is even the case if I have a wall selected. Please let me know if anything needs clarification.
Thanks,   
import clr
import math
clr.AddReference('RevitAPI') 
clr.AddReference('RevitAPIUI') 
from Autodesk.Revit.DB import * 

def pickobject():
    from Autodesk.Revit.UI.Selection import ObjectType
    __window__.Hide()
    picked = uidoc.Selection.PickObject(ObjectType.Element)
    __window__.Show()
    __window__.Topmost = True
    return picked

#set the active Revit application and document
app = __revit__.Application
doc = __revit__.ActiveUIDocument.Document

#define a transaction variable and describe the transaction
t = Transaction(doc, 'This is my new transaction')

#start a transaction in the Revit database
t.Start()

#perform some action here...

el = pickobject()    

p1 = XYZ(0,0,0)
p2 = XYZ(0,0,1)
myLine = Line.CreateBound(p1, p2)

ElementTransformUtils.RotateElement(doc, el.ElementId, myLine, math.pi / 2)

#commit the transaction to the Revit database
t.Commit()

#close the script window
__window__.Close()

It turns out I wasn't properly selecting an element or converting degrees to radians. After doing these things I was able to make my selected element rotate 90 degrees. The only problem I face now is choosing the origin at which the element rotates.

A:

I think what you're doing wrong is the angle.
This needs to be in radians. In your example that would be π/2.
See here

