Why have no attribute ‘ByCoordinates’?
It is difficult to help without seeing the whole script 
But… You might not have loaded the DS library containing e.g. Point.ByCoordinates.
(Also I do not like the space after your “append” why not simply write “linelist1.append(Line.ByStartPointEngPoint(a,b)” instead of line 40,41 
1 Like
I was wondering about that but if you don’t have the library, it will say NameError: name 'Point' is not defined
It is actually kind of hard to just replicate that error unless it has to do with language or conflicting libraries.
I guess you could try replacing the import with:
# Enable Python support and load DesignScript library
import clr
clr.AddReference('ProtoGeometry')
from Autodesk.DesignScript import *
and use this instead:
Geometry.Point.ByCoordinates(0,0,0)
But I agree with @Jonathan.Olesen that for us to really be able to help you, we need to see the whole code, or at least the import section.
1 Like
Thank you!
Thank you very much!