psycopg2/lib/extras.py
2004-10-19 03:17:12 +00:00

60 lines
1.9 KiB
Python

# psycopg/extras.py - miscellaneous extra goodies for psycopg
#
# Copyright (C) 2003-2004 Federico Di Gregorio <fog@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
from psycopg.extensions import cursor as _cursor
class DictCursor(_cursor):
"""A cursor that keeps a list of column name -> index mappings."""
__query_executed = 0
def execute(self, query, vars=None, async=0):
self.tuple_factory = DictRow
self.index = {}
self.__query_executed = 1
return _cursor.execute(self, query, vars, async)
def _build_index(self):
if self.description:
for i in range(len(self.description)):
self.index[self.description[i][0]] = i
def fetchone(self):
if self.__query_executed:
self._build_index()
return _cursor.fetchone(self)
def fetchmany(self, size=None):
if self.__query_executed:
self._build_index()
return _cursor.fetchmany(self, size)
def fetchall(self):
if self.__query_executed:
self._build_index()
return _cursor.fetchall(self)
class DictRow(list):
"""A row object that allow by-colun-name access to data."""
def __init__(self, cursor):
self._cursor = cursor
self[:] = [None] * len(cursor.description)
print cursor, self
def __getitem__(self, x):
if type(x) != int:
x = self._cursor.index[x]
return list.__getitem__(self, x)