Class NMFace

The NMFace object

This object holds mesh face data.

import Blender
from Blender import NMesh

me = NMesh.GetRaw("Mesh")
faces = me.faces
selected_faces = []
SEL = NMesh.FaceFlags['SELECT']
# get selected faces:
for f in faces:
  if f.flag & SEL:
  selected_faces.append(f)
# ... unselect selected and select all the others:
for f in faces:
  if f.flag & SEL:
    f.flag &=~SEL # unselect these
  else: f.flag |= SEL # and select these

Note: Assigning uv textures to mesh faces in Blender works like this:

1. Select your mesh.
2. Enter face select mode (press f) and select at least some face(s).
3. In the UV/Image Editor window, load / select an image.
4. Play in both windows (better split the screen to see both at the same time) until the uv coordinates are where you want them. Hint: in the 3d window, the 'u' key opens a menu of default uv choices and the 'r' key lets you rotate the uv coords.
5. Leave face select mode (press f).