ob_item contains space for 'allocated' elements. The number
currently in use is ob_size.
Invariants:
0 <= ob_size <= allocated
len(list) == ob_size
ob_item == NULL implies ob_size == allocated == 0
list.sort() temporarily sets allocated to -1 to detect mutations.
Items must normally not be NULL, except during construction when
the list is not yet visible outside the function that builds it.
ob_item contains space for 'allocated' elements. The number currently in use is ob_size. Invariants: 0 <= ob_size <= allocated len(list) == ob_size ob_item == NULL implies ob_size == allocated == 0 list.sort() temporarily sets allocated to -1 to detect mutations.
Items must normally not be NULL, except during construction when the list is not yet visible outside the function that builds it.
subclass of PyObject.