...system().1.11.1
An interface for this function already exists in the standard module os — it was chosen as a simple and straightfoward example.
...borrow1.21.2
The metaphor of ``borrowing'' a reference is not completely correct: the owner still has a copy of the reference.
... completely.1.31.3
Checking that the reference count is at least 1 does not work — the reference count itself could be in freed memory and may thus be reused for another object!
...1.41.4
These guarantees don't hold when you use the ``old'' style calling convention — this is still found in much existing code.
... directory.3.13.1
Check the manual page of the dl package for details.