Large memory footprint of integers compared with result of sys.getsizeof()

Question

Python-Integer-objects in the range [1,2^30) need 28 byte, as provided by sys.getsizeof() and explained for example in this SO-post.

Answer 1

The int object only requires 28 bytes, but Python uses 8-byte alignment: memory is allocated in blocks that are multiples of 8 bytes in size. So the actual memory used by each int object is 32 bytes. See this excellent article on Python memory management for more details.

I don't yet have an explanation for the remaining half byte, but I'll update this if I find one.