Error on processing placeholders with negative integer

Submitted by: nk.0@ya.ru (Konstantin Nikitin)

Here is my error log

import psycopg2 connection = psycopg2.connect("user=konstantin dbname=konstantin") cursor = connection.cursor() cursor.execute("select 1-%s from table", (2, )) cursor.fetchall() [(-1,), (-1,), (-1,), (-1,), (-1,), (-1,), (-1,), (-1,)] cursor.execute("select 1-%s from table", (-1, )) cursor.fetchall() [(1,)] cursor.execute("select 1 - %s from table", (-1, )) cursor.fetchall() [(2,), (2,), (2,), (2,), (2,), (2,), (2,), (2,)]