[LibPQ] Trying PQconnectStart: it doesn't seem to connect

Hi,
i'm a python/c developer and i need an asynchronous (python) interface to
communicate with a database. I like PostgreSQL so i'm trying to write a
mock-up for a python extension module to use LibPQ in my asynchronous
programs.

I've started to study the docs about libpq just yesterday, so if i mistake
something please correct me.
I'm writing the connection function, using the api PQconnectStart but
verifing the status of this call i get that the condition
PQstatus(connection) != CONNECTION_OK (the connection must return
CONNECTION_OK) is failed so my program exits. Using instead of it the
PQconnectiondb all work as expected, but not using this api.

Can someone tell me what i wrong? And if you know some resource that
explains with an example how i should to verify the connection during the
select/poll, would be appreciated.

Thank you,
Alex.
--
Alessandro A.