cursor.executemany generates multiple INSERTs

Hi,

When using executemany to do a bulk insert, psycopg2 generates an
INSERT for each item in the given sequence of items.

This is a lot slower than a single INSERT using Postgres multirow
VALUES syntax, e.g.

INSERT INTO films (code, title, did, date_prod, kind) VALUES
('B6717', 'Tampopo', 110, '1985-02-10', 'Comedy'),
('HG120', 'The Dinner Game', 140, DEFAULT, 'Comedy');

Why doesn't psycopg2 use this syntax?