Deleting a face from a mesh

if you are modifying data of an object, sometimes you want to remove a face

# must be in edit mode.

# first select the face, then delete it. 
mplane.data.faces[-1].select = True   # won't show in viewport
bpy.ops.mesh.delete(type='ONLY_FACE') # will be acted on.

must be in edit mode for these options, other options for types are found by reading the tooltips in the delete menu.