There is a quite a lot of redundancy in code, function and generator objects.

Intra-object redundancy

1. Code objects have four fields ,co_nlocalsplus, co_nplaincellvars, co_nlocals, co_nfreevars. Any of these fields can be computed from the other three.
2. Code objects have a qualified name and a name. The name is always the suffix of the qualified name. Changing this to qualifying prefix and name would save space and allow sharing.
3. The defaults and keyword defaults for a function are separate and the keyword defaults are a dict. They could be combined into a single array.
4. Generator objects have a gi_code field, which is redundant, as the frame contains a reference to the code object.

Inter-object redundancy

1. Functions and generators have qualified name and name fields, which are almost always the same as the underlying code object. These should be lazily initialized

Linked PRs

• GH-100719: Remove the co_nplaincellvars field from code objects. #100721
• GH-100719: Remove redundant gi_code field from generator object. #100749