psycopg2/examples/encoding.py

# encoding.py - show to change client encoding (and test it works)
# -*- encoding: utf8 -*-
#
# Copyright (C) 2004-2010 Federico Di Gregorio  <fog@debian.org>
#
# psycopg2 is free software: you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# psycopg2 is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
# License for more details.

## put in DSN your DSN string

DSN = 'dbname=test'

## don't modify anything below this line (except for experimenting)

import sys
import psycopg2
import psycopg2.extensions

if len(sys.argv) > 1:
    DSN = sys.argv[1]

print("Opening connection using dsn:", DSN)
conn = psycopg2.connect(DSN)
print("Initial encoding for this connection is", conn.encoding)

print("\n** This example is supposed to be run in a UNICODE terminal! **\n")

print("Available encodings:")
encs = psycopg2.extensions.encodings.items()
encs.sort()
for a, b in encs:
    print(" ", a, "<->", b)

print("Using STRING typecaster")
print("Setting backend encoding to LATIN1 and executing queries:")
conn.set_client_encoding('LATIN1')
curs = conn.cursor()
curs.execute("SELECT %s::TEXT AS foo", ('àèìòù',))
x = curs.fetchone()[0]
print("  ->", unicode(x, 'latin-1').encode('utf-8'), type(x))
curs.execute("SELECT %s::TEXT AS foo", (u'àèìòù',))
x = curs.fetchone()[0]
print("  ->", unicode(x, 'latin-1').encode('utf-8'), type(x))

print("Setting backend encoding to UTF8 and executing queries:")
conn.set_client_encoding('UNICODE')
curs = conn.cursor()
curs.execute("SELECT %s::TEXT AS foo", (u'àèìòù'.encode('utf-8'),))
x = curs.fetchone()[0]
print("  ->", x, type(x))
curs.execute("SELECT %s::TEXT AS foo", (u'àèìòù',))
x = curs.fetchone()[0]
print("  ->", x, type(x))

print("Using UNICODE typecaster")
psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)

print("Setting backend encoding to LATIN1 and executing queries:")
conn.set_client_encoding('LATIN1')
curs = conn.cursor()
curs.execute("SELECT %s::TEXT AS foo", ('àèìòù',))
x = curs.fetchone()[0]
print("  ->", x.encode('utf-8'), ":", type(x))
curs.execute("SELECT %s::TEXT AS foo", (u'àèìòù',))
x = curs.fetchone()[0]
print("  ->", x.encode('utf-8'), ":", type(x))

print("Setting backend encoding to UTF8 and executing queries:")
conn.set_client_encoding('UNICODE')
curs = conn.cursor()
curs.execute("SELECT %s::TEXT AS foo", (u'àèìòù'.encode('utf-8'),))
x = curs.fetchone()[0]
print("  ->", x.encode('utf-8'), ":", type(x))
curs.execute("SELECT %s::TEXT AS foo", (u'àèìòù',))
x = curs.fetchone()[0]
print("  ->", x.encode('utf-8'), ":", type(x))

print("Executing full UNICODE queries")

print("Setting backend encoding to LATIN1 and executing queries:")
conn.set_client_encoding('LATIN1')
curs = conn.cursor()
curs.execute(u"SELECT %s::TEXT AS foo", ('àèìòù',))
x = curs.fetchone()[0]
print("  ->", x.encode('utf-8'), ":", type(x))
curs.execute(u"SELECT %s::TEXT AS foo", (u'àèìòù',))
x = curs.fetchone()[0]
print("  ->", x.encode('utf-8'), ":", type(x))

print("Setting backend encoding to UTF8 and executing queries:")
conn.set_client_encoding('UNICODE')
curs = conn.cursor()
curs.execute(u"SELECT %s::TEXT AS foo", (u'àèìòù'.encode('utf-8'),))
x = curs.fetchone()[0]
print("  ->", x.encode('utf-8'), ":", type(x))
curs.execute(u"SELECT %s::TEXT AS foo", (u'àèìòù',))
x = curs.fetchone()[0]
print("  ->", x.encode('utf-8'), ":", type(x))