Deleting Objects from a scene

There might be quicker ways of doing this, but this describes the process.

# do not run this on a scene with more than 100 objects... it will be a waste of time. (printing is slow)
for item in bpy.data.objects:
... print(item.name, item.type)
... 

# objects of type mesh are containers for meshes.
# multiple differently named objects can share the same base mesh.
# objects are in that sense 'users' of mesh data.
for item in bpy.data.objects:
... if item.type == "MESH":
...     print(item.name)
... 
Mesh
Mesh.001

for mesh in bpy.data.meshes:
... print(mesh.name)
... 
Cube
Cube.001
Cube.002

# maybe use some blender forensics to consider the two printed sequences above. 
# what must I have done to have 3 mesh structures, but only 2 objects of type 'MESH'? 

we can't delete mesh data if an object uses it. And simply deleting an object doesn't flush the mesh it used (altho I do recall seeing a method that does exactly that) or if you can do a broad stroke:

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.