Abaqus scripting: Create a Set from a Face object

Question

I created in Abaqus v6.14 scripting an extruded Part p with BaseSolidExtrude, which is then a cylinder (not necessarily circular). I want to create three sets, one for the top and bottom surface, and one for the lateral surface. The first two are easy, with

faces = p.faces
face_bot = faces.findAt((p_center_bot,))
face_top = faces.findAt((p_center_top,))
p.Set(faces=face_bot, name='Set-face-bot')
p.Set(faces=face_top, name='Set-face-top')

But I couldn't find a way to create a Set for the lateral face, even if for the time being, I have the advantage that these are the only 3 faces. I tried extracting the indexes of face_bot, face_top with

face_bot_idx = face_bot[0].index
face_top_idx = face_top[0].index

(note that face_bot and face_top are of type Sequence, having only one element each, so I extract element 0 in each case) and excluding them from the list of indexes of the 3 faces, so I get the index of my face_lat_0 with

# Of the 3 faces, get the one not being bottom or top
face_lat_idx = [idx for idx in range(len(faces)) if ((idx!=face_bot_idx) and (idx!=face_top_idx))][0]

But given that Face object, I was unable to create the needed Sequence face_lat. Note that the named argument faces requires a Sequence, and it seems not to accept a tuple like (face_lat_0,) or list like [face_lat_0].

If I am correct that no list or tuple can be used, I need to create a Sequence. I found method getSequenceFromMask(...), but I don't know how to generate the mask for face_lat_0, given its index.

Alternatively, I could try using named argument xFaces, but I guess I would need a Sequence containing face_bot[0] and face_top[0] to be excluded, which again I don't know how to build.

Any ideas?

Possibly related (although I didn't find the answer there):

1. Abaqus Surface getSequenceFromMask
2. Abaqus get face object
3. Abaqus: script to select elements on a surface
4. how to select part.surface in abaqus using python script
5. https://imechanica.org/node/15852

Answer 1

More straightforward option would be to use SetByBoolean(...). There is no need for intermediate sets since,

Note that if DIFFERENCE is specified, the order of the given input sets is important; All sets specified after the first one are subtracted from the first one.

faces = p.faces
face_bot = faces.findAt((p_center_bot,))
face_top = faces.findAt((p_center_top,))

Surf_face_all = p.Set(faces=faces,    name='Set-face-all')
Surf_face_bot = p.Set(faces=face_bot, name='Set-face-bot')
Surf_face_top = p.Set(faces=face_top, name='Set-face-top')

# Create a lateral surface set by subtracting the top and bottom
p.SetByBoolean(name='Set_lateral_surface', 
               sets=(Surf_face_all, Surf_face_bot, Surf_face_bot),
               operation=DIFFERENCE)

Answer 2

You can make use of FaceArray method from part module which creates a sequence of faces. If the part is modified, then FaceArray must be updated for that part.

Argument: faces - A list of Face objects.

import part
# Get the one not being bottom or top
faces_list = []
for face_ in faces:
  if (face_.index != face_bot_idx) or face_.index != face_top_idx):
    faces_list.append(face_)

# Create a sequence of array from list of faces
face_seq = part.FaceArray(faces_list)

# Use that to create set
p.Set(faces=face_seq, name='Set-face-lat')