Proposals like this have been rejected in the past.  Memory consumption 
is an evasive concept.  Lists over-allocate space, there are freelists, 
there are immortal objects, the python memory allocator may hang-on to 
space thought to be available, the packing and alignment of structures 
varies across implementations, the system memory allocator may assign 
much larger chunks than are needed for a single object, and the memory 
may not be freed back to the system.  Because of these issues, it is 
not that meaningful to say the object x consumes y bytes.