FWIW, i counted the difference of each file's refs after `Py_Finalize()`.

[('Objects/dictobject.c', 21434), ('Python/marshal.c', 8135), ('Objects/codeobject.c', 6245), ('Objects/listobject.c', 6037), ('Objects/tupleobject.c', 4169), ('Objects/boolobject.c', 2433), ('Objects/object.c', 2364), ('Objects/unicodeobject.c', 1541), ('Objects/longobject.c', 1387), ('Objects/funcobject.c', 528), ('Objects/classobject.c', 528), ('Objects/abstract.c', 463), ('Python/structmember.c', 369), ('./Include/objimpl.h', 277), ('Objects/stringlib/partition.h', 273), ('Python/import.c', 259), ('Python/codecs.c', 197), ('./Modules/signalmodule.c', 61), ('./Modules/_threadmodule.c', 59), ('Objects/exceptions.c', 15), ('Objects/bytesobject.c', 5), ('./Modules/_weakref.c', 4), ('Python/_warnings.c', 3), ('./Modules/timemodule.c', 1), ('./Modules/_codecsmodule.c', 1), ('Objects/bytearrayobject.c', 1), ('Python/compile.c', 1), ('Objects/sliceobject.c', 0), ('Objects/memoryobject.c', 0), ('Python/context.c', -1), ('Objects/clinic/longobject.c.h', -1), ('Objects/enumobject.c', -1), ('Modules/gcmodule.c', -1), ('Objects/namespaceobject.c', -1), ('Objects/stringlib/unicode_format.h', -2), ('Objects/rangeobject.c', -3), ('Python/pystate.c', -4), ('Objects/fileobject.c', -14), ('./Modules/_io/clinic/bufferedio.c.h', -17), ('./Modules/_io/iobase.c', -21), ('Python/modsupport.c', -28), ('./Modules/_io/fileio.c', -28), ('Python/pylifecycle.c', -37), ('./Modules/_io/textio.c', -39), ('Objects/genobject.c', -53), ('Objects/weakrefobject.c', -54), ('./Modules/_io/bufferedio.c', -56), ('./Python/sysmodule.c', -68), ('./Modules/_io/_iomodule.c', -82), ('Python/errors.c', -90), ('Objects/descrobject.c', -110), ('Objects/structseq.c', -113), ('Python/bltinmodule.c', -118), ('Objects/setobject.c', -339), ('Objects/moduleobject.c', -454), ('./Modules/posixmodule.c', -614), ('./Modules/_abc.c', -664), ('Objects/call.c', -755), ('Objects/typeobject.c', -2035), ('Objects/frameobject.c', -6538), ('Python/ceval.c', -7857), ('./Include/object.h', -48292)]