http://docs.python.org/lib/sqlite3-Cursor-Objects.html
says:

----
For SELECT statements, rowcount is always None because
we cannot determine the number of rows a query produced
until all rows were fetched.

As required by the Python DB API Spec, the rowcount
attribute "is -1 in case no executeXX() has been
performed on the cursor or the rowcount of the last
operation is not determinable by the interface".
----

Clearly, both can't be true. My experiment showed that
rowcount is set to -1, not None. I suggest rewriting
this to something like:

----
As required by the Python DB API Spec, the rowcount
attribute "is -1 in case no executeXX() has been
performed on the cursor or the rowcount of the last
operation is not determinable by the interface".

This includes SELECT statements, because we cannot
determine the number of rows a query produced until all
rows are fetched.
----