sql = '''
CREATE TABLE IF NOT EXISTS sites.hist_id_site (
    id serial4 NOT NULL,
    id_site_old varchar(10) NOT NULL,
    id_site_new varchar(10) NOT NULL,
    "date" timestamp NOT NULL DEFAULT NOW(),
	CONSTRAINT hist_id_site_pkey PRIMARY KEY (id),
	CONSTRAINT hist_id_site_un UNIQUE (id_site_old, id_site_new)
);'''

with con.begin() as cnx:
    cnx.execute(sql)