import psycopg

db = psycopg.connect('dbname=test')
c = db.cursor()
str = "hel'lo"
c.execute("select %(text)s where %(text)s <> ''", { 'text': str})
db.commit()
for i in  c.fetchall():
    print i

c.execute("select %(text)s where %(text)s <> ''", { 'text': psycopg.Binary(str)})
db.commit()
for i in  c.fetchall():
    print i