1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Module functions and constants — PyGreSQL 5.0 documentation</title>
<link rel="stylesheet" href="../../_static/cloud.css" type="text/css" />
<link rel="stylesheet" href="../../_static/pygments.css" type="text/css" />
<link rel="stylesheet" href="../../_static/pygresql.css" type="text/css" />
<link rel="stylesheet" href="//fonts.googleapis.com/css?family=Noticia+Text|Open+Sans|Droid+Sans+Mono" type="text/css" />
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT: '../../',
VERSION: '5.0.3',
COLLAPSE_INDEX: false,
FILE_SUFFIX: '.html',
HAS_SOURCE: true
};
</script>
<script type="text/javascript" src="../../_static/jquery.js"></script>
<script type="text/javascript" src="../../_static/underscore.js"></script>
<script type="text/javascript" src="../../_static/doctools.js"></script>
<script type="text/javascript" src="../../_static/jquery.cookie.js"></script>
<script type="text/javascript" src="../../_static/cloud.js"></script>
<link rel="shortcut icon" href="../../_static/favicon.ico"/>
<link rel="copyright" title="Copyright" href="../../copyright.html" />
<link rel="top" title="PyGreSQL 5.0 documentation" href="../index.html" />
<link rel="up" title="pg — The Classic PyGreSQL Interface" href="index.html" />
<link rel="next" title="Connection – The connection object" href="connection.html" />
<link rel="prev" title="Introduction" href="introduction.html" />
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body role="document">
<div class="pageheader related" role="navigation" aria-label="related navigation">
<ul>
<li><a href="../../index.html">Home</a></li>
<li><a href="../../download/index.html">Download</a></li>
<li><a href="../index.html">Documentation</a></li>
<li><a href="../../community/index.html">Community</a></li>
</ul>
<div class="logo">
<a href="../../index.html">PyGreSQL</a>
</div>
</div>
</div>
<div class="relbar-top">
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="../../genindex.html" title="General Index"
accesskey="I">index</a></li>
<li class="right" >
<a href="../../py-modindex.html" title="Python Module Index"
>modules</a> </li>
<li class="right" >
<a href="connection.html" title="Connection – The connection object"
accesskey="N">next</a> </li>
<li class="right" >
<a href="introduction.html" title="Introduction"
accesskey="P">previous</a> </li>
<li><a href="../index.html">PyGreSQL 5.0 documentation</a> »</li>
<li class="nav-item nav-item-1"><a href="index.html" accesskey="U"><code class="docutils literal"><span class="pre">pg</span></code> — The Classic PyGreSQL Interface</a> »</li>
</ul>
</div>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<div class="section" id="module-functions-and-constants">
<h1>Module functions and constants<a class="headerlink" href="#module-functions-and-constants" title="Permalink to this headline">¶</a></h1>
<p>The <a class="reference internal" href="index.html#module-pg" title="pg"><code class="xref py py-mod docutils literal"><span class="pre">pg</span></code></a> module defines a few functions that allow to connect
to a database and to define “default variables” that override
the environment variables used by PostgreSQL.</p>
<p>These “default variables” were designed to allow you to handle general
connection parameters without heavy code in your programs. You can prompt the
user for a value, put it in the default variable, and forget it, without
having to modify your environment. The support for default variables can be
disabled by setting the <code class="docutils literal"><span class="pre">-DNO_DEF_VAR</span></code> option in the Python setup file.
Methods relative to this are specified by the tag [DV].</p>
<p>All variables are set to <code class="docutils literal"><span class="pre">None</span></code> at module initialization, specifying that
standard environment variables should be used.</p>
<div class="section" id="connect-open-a-postgresql-connection">
<h2>connect – Open a PostgreSQL connection<a class="headerlink" href="#connect-open-a-postgresql-connection" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.connect">
<code class="descclassname">pg.</code><code class="descname">connect</code><span class="sig-paren">(</span><span class="optional">[</span><em>dbname</em><span class="optional">]</span><span class="optional">[</span>, <em>host</em><span class="optional">]</span><span class="optional">[</span>, <em>port</em><span class="optional">]</span><span class="optional">[</span>, <em>opt</em><span class="optional">]</span><span class="optional">[</span>, <em>user</em><span class="optional">]</span><span class="optional">[</span>, <em>passwd</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.connect" title="Permalink to this definition">¶</a></dt>
<dd><p>Open a <a class="reference internal" href="index.html#module-pg" title="pg"><code class="xref py py-mod docutils literal"><span class="pre">pg</span></code></a> connection</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>dbname</strong> – name of connected database (<em>None</em> = <code class="xref py py-data docutils literal"><span class="pre">defbase</span></code>)</li>
<li><strong>host</strong> (<em>str or None</em>) – name of the server host (<em>None</em> = <code class="xref py py-data docutils literal"><span class="pre">defhost</span></code>)</li>
<li><strong>port</strong> (<em>int</em>) – port used by the database server (-1 = <code class="xref py py-data docutils literal"><span class="pre">defport</span></code>)</li>
<li><strong>opt</strong> (<em>str or None</em>) – connection options (<em>None</em> = <code class="xref py py-data docutils literal"><span class="pre">defopt</span></code>)</li>
<li><strong>user</strong> (<em>str or None</em>) – PostgreSQL user (<em>None</em> = <code class="xref py py-data docutils literal"><span class="pre">defuser</span></code>)</li>
<li><strong>passwd</strong> (<em>str or None</em>) – password for user (<em>None</em> = <code class="xref py py-data docutils literal"><span class="pre">defpasswd</span></code>)</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">If successful, the <a class="reference internal" href="connection.html#pg.Connection" title="pg.Connection"><code class="xref py py-class docutils literal"><span class="pre">Connection</span></code></a> handling the connection</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="connection.html#pg.Connection" title="pg.Connection"><code class="xref py py-class docutils literal"><span class="pre">Connection</span></code></a></p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><ul class="first last simple">
<li><strong>TypeError</strong> – bad argument type, or too many arguments</li>
<li><strong>SyntaxError</strong> – duplicate argument definition</li>
<li><strong>pg.InternalError</strong> – some error occurred during pg connection definition</li>
<li><strong>Exception</strong> – (all exceptions relative to object allocation)</li>
</ul>
</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function opens a connection to a specified database on a given
PostgreSQL server. You can use keywords here, as described in the
Python tutorial. The names of the keywords are the name of the
parameters given in the syntax line. For a precise description
of the parameters, please refer to the PostgreSQL user manual.</p>
<p>Example:</p>
<div class="highlight-default"><div class="highlight"><pre><span class="kn">import</span> <span class="nn">pg</span>
<span class="n">con1</span> <span class="o">=</span> <span class="n">pg</span><span class="o">.</span><span class="n">connect</span><span class="p">(</span><span class="s">'testdb'</span><span class="p">,</span> <span class="s">'myhost'</span><span class="p">,</span> <span class="mi">5432</span><span class="p">,</span> <span class="k">None</span><span class="p">,</span> <span class="k">None</span><span class="p">,</span> <span class="s">'bob'</span><span class="p">,</span> <span class="k">None</span><span class="p">)</span>
<span class="n">con2</span> <span class="o">=</span> <span class="n">pg</span><span class="o">.</span><span class="n">connect</span><span class="p">(</span><span class="n">dbname</span><span class="o">=</span><span class="s">'testdb'</span><span class="p">,</span> <span class="n">host</span><span class="o">=</span><span class="s">'localhost'</span><span class="p">,</span> <span class="n">user</span><span class="o">=</span><span class="s">'bob'</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="get-set-defhost-default-server-host-dv">
<h2>get/set_defhost – default server host [DV]<a class="headerlink" href="#get-set-defhost-default-server-host-dv" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_defhost">
<code class="descclassname">pg.</code><code class="descname">get_defhost</code><span class="sig-paren">(</span><em>host</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_defhost" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the default host</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">the current default host specification</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-odd field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method returns the current default host specification,
or <code class="docutils literal"><span class="pre">None</span></code> if the environment variables should be used.
Environment variables won’t be looked up.</p>
<dl class="function">
<dt id="pg.set_defhost">
<code class="descclassname">pg.</code><code class="descname">set_defhost</code><span class="sig-paren">(</span><em>host</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_defhost" title="Permalink to this definition">¶</a></dt>
<dd><p>Set the default host</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>host</strong> (<em>str or None</em>) – the new default host specification</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">the previous default host specification</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – bad argument type, or too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This methods sets the default host value for new connections.
If <code class="docutils literal"><span class="pre">None</span></code> is supplied as parameter, environment variables will
be used in future connections. It returns the previous setting
for default host.</p>
</div>
<div class="section" id="get-set-defport-default-server-port-dv">
<h2>get/set_defport – default server port [DV]<a class="headerlink" href="#get-set-defport-default-server-port-dv" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_defport">
<code class="descclassname">pg.</code><code class="descname">get_defport</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_defport" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the default port</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">the current default port specification</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">int</td>
</tr>
<tr class="field-odd field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method returns the current default port specification,
or <code class="docutils literal"><span class="pre">None</span></code> if the environment variables should be used.
Environment variables won’t be looked up.</p>
<dl class="function">
<dt id="pg.set_defport">
<code class="descclassname">pg.</code><code class="descname">set_defport</code><span class="sig-paren">(</span><em>port</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_defport" title="Permalink to this definition">¶</a></dt>
<dd><p>Set the default port</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>port</strong> (<em>int</em>) – the new default port</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">previous default port specification</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">int or None</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This methods sets the default port value for new connections. If -1 is
supplied as parameter, environment variables will be used in future
connections. It returns the previous setting for default port.</p>
</div>
<div class="section" id="get-set-defopt-default-connection-options-dv">
<h2>get/set_defopt – default connection options [DV]<a class="headerlink" href="#get-set-defopt-default-connection-options-dv" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_defopt">
<code class="descclassname">pg.</code><code class="descname">get_defopt</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_defopt" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the default connection options</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">the current default options specification</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-odd field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method returns the current default connection options specification,
or <code class="docutils literal"><span class="pre">None</span></code> if the environment variables should be used. Environment variables
won’t be looked up.</p>
<dl class="function">
<dt id="pg.set_defopt">
<code class="descclassname">pg.</code><code class="descname">set_defopt</code><span class="sig-paren">(</span><em>options</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_defopt" title="Permalink to this definition">¶</a></dt>
<dd><p>Set the default connection options</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>options</strong> (<em>str or None</em>) – the new default connection options</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">previous default options specification</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – bad argument type, or too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This methods sets the default connection options value for new connections.
If <code class="docutils literal"><span class="pre">None</span></code> is supplied as parameter, environment variables will be used in
future connections. It returns the previous setting for default options.</p>
</div>
<div class="section" id="get-set-defbase-default-database-name-dv">
<h2>get/set_defbase – default database name [DV]<a class="headerlink" href="#get-set-defbase-default-database-name-dv" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_defbase">
<code class="descclassname">pg.</code><code class="descname">get_defbase</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_defbase" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the default database name</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">the current default database name specification</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-odd field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method returns the current default database name specification, or
<code class="docutils literal"><span class="pre">None</span></code> if the environment variables should be used. Environment variables
won’t be looked up.</p>
<dl class="function">
<dt id="pg.set_defbase">
<code class="descclassname">pg.</code><code class="descname">set_defbase</code><span class="sig-paren">(</span><em>base</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_defbase" title="Permalink to this definition">¶</a></dt>
<dd><p>Set the default database name</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>base</strong> (<em>str or None</em>) – the new default base name</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">the previous default database name specification</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – bad argument type, or too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method sets the default database name value for new connections. If
<code class="docutils literal"><span class="pre">None</span></code> is supplied as parameter, environment variables will be used in
future connections. It returns the previous setting for default host.</p>
</div>
<div class="section" id="get-set-defuser-default-database-user-dv">
<h2>get/set_defuser – default database user [DV]<a class="headerlink" href="#get-set-defuser-default-database-user-dv" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_defuser">
<code class="descclassname">pg.</code><code class="descname">get_defuser</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_defuser" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the default database user</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">the current default database user specification</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-odd field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method returns the current default database user specification, or
<code class="docutils literal"><span class="pre">None</span></code> if the environment variables should be used. Environment variables
won’t be looked up.</p>
<dl class="function">
<dt id="pg.set_defuser">
<code class="descclassname">pg.</code><code class="descname">set_defuser</code><span class="sig-paren">(</span><em>user</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_defuser" title="Permalink to this definition">¶</a></dt>
<dd><p>Set the default database user</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>user</strong> – the new default database user</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">the previous default database user specification</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – bad argument type, or too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method sets the default database user name for new connections. If
<code class="docutils literal"><span class="pre">None</span></code> is supplied as parameter, environment variables will be used in
future connections. It returns the previous setting for default host.</p>
</div>
<div class="section" id="get-set-defpasswd-default-database-password-dv">
<h2>get/set_defpasswd – default database password [DV]<a class="headerlink" href="#get-set-defpasswd-default-database-password-dv" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_defpasswd">
<code class="descclassname">pg.</code><code class="descname">get_defpasswd</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_defpasswd" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the default database password</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">the current default database password specification</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-odd field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method returns the current default database password specification, or
<code class="docutils literal"><span class="pre">None</span></code> if the environment variables should be used. Environment variables
won’t be looked up.</p>
<dl class="function">
<dt id="pg.set_defpasswd">
<code class="descclassname">pg.</code><code class="descname">set_defpasswd</code><span class="sig-paren">(</span><em>passwd</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_defpasswd" title="Permalink to this definition">¶</a></dt>
<dd><p>Set the default database password</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>passwd</strong> – the new default database password</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">the previous default database password specification</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">str or None</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – bad argument type, or too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This method sets the default database password for new connections. If
<code class="docutils literal"><span class="pre">None</span></code> is supplied as parameter, environment variables will be used in
future connections. It returns the previous setting for default host.</p>
</div>
<div class="section" id="escape-string-escape-a-string-for-use-within-sql">
<h2>escape_string – escape a string for use within SQL<a class="headerlink" href="#escape-string-escape-a-string-for-use-within-sql" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.escape_string">
<code class="descclassname">pg.</code><code class="descname">escape_string</code><span class="sig-paren">(</span><em>string</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.escape_string" title="Permalink to this definition">¶</a></dt>
<dd><p>Escape a string for use within SQL</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>string</strong> (<em>str</em>) – the string that is to be escaped</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">the escaped string</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">str</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – bad argument type, or too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function escapes a string for use within an SQL command.
This is useful when inserting data values as literal constants
in SQL commands. Certain characters (such as quotes and backslashes)
must be escaped to prevent them from being interpreted specially
by the SQL parser. <a class="reference internal" href="#pg.escape_string" title="pg.escape_string"><code class="xref py py-func docutils literal"><span class="pre">escape_string()</span></code></a> performs this operation.
Note that there is also a <a class="reference internal" href="connection.html#pg.Connection" title="pg.Connection"><code class="xref py py-class docutils literal"><span class="pre">Connection</span></code></a> method with the same name
which takes connection properties into account.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">It is especially important to do proper escaping when
handling strings that were received from an untrustworthy source.
Otherwise there is a security risk: you are vulnerable to “SQL injection”
attacks wherein unwanted SQL commands are fed to your database.</p>
</div>
<p>Example:</p>
<div class="highlight-default"><div class="highlight"><pre><span class="n">name</span> <span class="o">=</span> <span class="nb">input</span><span class="p">(</span><span class="s">"Name? "</span><span class="p">)</span>
<span class="n">phone</span> <span class="o">=</span> <span class="n">con</span><span class="o">.</span><span class="n">query</span><span class="p">(</span><span class="s">"select phone from employees where name='%s'"</span>
<span class="o">%</span> <span class="n">escape_string</span><span class="p">(</span><span class="n">name</span><span class="p">))</span><span class="o">.</span><span class="n">getresult</span><span class="p">()</span>
</pre></div>
</div>
</div>
<div class="section" id="escape-bytea-escape-binary-data-for-use-within-sql">
<h2>escape_bytea – escape binary data for use within SQL<a class="headerlink" href="#escape-bytea-escape-binary-data-for-use-within-sql" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.escape_bytea">
<code class="descclassname">pg.</code><code class="descname">escape_bytea</code><span class="sig-paren">(</span><em>datastring</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.escape_bytea" title="Permalink to this definition">¶</a></dt>
<dd><p>escape binary data for use within SQL as type <code class="docutils literal"><span class="pre">bytea</span></code></p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>datastring</strong> (<em>str</em>) – string containing the binary data that is to be escaped</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">the escaped string</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">str</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – bad argument type, or too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>Escapes binary data for use within an SQL command with the type <code class="docutils literal"><span class="pre">bytea</span></code>.
As with <a class="reference internal" href="#pg.escape_string" title="pg.escape_string"><code class="xref py py-func docutils literal"><span class="pre">escape_string()</span></code></a>, this is only used when inserting data directly
into an SQL command string.</p>
<p>Note that there is also a <a class="reference internal" href="connection.html#pg.Connection" title="pg.Connection"><code class="xref py py-class docutils literal"><span class="pre">Connection</span></code></a> method with the same name
which takes connection properties into account.</p>
<p>Example:</p>
<div class="highlight-default"><div class="highlight"><pre><span class="n">picture</span> <span class="o">=</span> <span class="nb">open</span><span class="p">(</span><span class="s">'garfield.gif'</span><span class="p">,</span> <span class="s">'rb'</span><span class="p">)</span><span class="o">.</span><span class="n">read</span><span class="p">()</span>
<span class="n">con</span><span class="o">.</span><span class="n">query</span><span class="p">(</span><span class="s">"update pictures set img='%s' where name='Garfield'"</span>
<span class="o">%</span> <span class="n">escape_bytea</span><span class="p">(</span><span class="n">picture</span><span class="p">))</span>
</pre></div>
</div>
</div>
<div class="section" id="unescape-bytea-unescape-data-that-has-been-retrieved-as-text">
<h2>unescape_bytea – unescape data that has been retrieved as text<a class="headerlink" href="#unescape-bytea-unescape-data-that-has-been-retrieved-as-text" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.unescape_bytea">
<code class="descclassname">pg.</code><code class="descname">unescape_bytea</code><span class="sig-paren">(</span><em>string</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.unescape_bytea" title="Permalink to this definition">¶</a></dt>
<dd><p>Unescape <code class="docutils literal"><span class="pre">bytea</span></code> data that has been retrieved as text</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>datastring</strong> (<em>str</em>) – the <code class="docutils literal"><span class="pre">bytea</span></code> data string that has been retrieved as text</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">byte string containing the binary data</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">bytes</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><strong>TypeError</strong> – bad argument type, or too many arguments</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>Converts an escaped string representation of binary data stored as <code class="docutils literal"><span class="pre">bytea</span></code>
into the raw byte string representing the binary data – this is the reverse
of <a class="reference internal" href="#pg.escape_bytea" title="pg.escape_bytea"><code class="xref py py-func docutils literal"><span class="pre">escape_bytea()</span></code></a>. Since the <a class="reference internal" href="query.html#pg.Query" title="pg.Query"><code class="xref py py-class docutils literal"><span class="pre">Query</span></code></a> results will already
return unescaped byte strings, you normally don’t have to use this method.</p>
<p>Note that there is also a <a class="reference internal" href="db_wrapper.html#pg.DB" title="pg.DB"><code class="xref py py-class docutils literal"><span class="pre">DB</span></code></a> method with the same name
which does exactly the same.</p>
</div>
<div class="section" id="get-set-namedresult-conversion-to-named-tuples">
<h2>get/set_namedresult – conversion to named tuples<a class="headerlink" href="#get-set-namedresult-conversion-to-named-tuples" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_namedresult">
<code class="descclassname">pg.</code><code class="descname">get_namedresult</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_namedresult" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the function that converts to named tuples</p>
</dd></dl>
<p>This returns the function used by PyGreSQL to construct the result of the
<a class="reference internal" href="query.html#pg.Query.namedresult" title="pg.Query.namedresult"><code class="xref py py-meth docutils literal"><span class="pre">Query.namedresult()</span></code></a> method.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 4.1.</span></p>
</div>
<dl class="function">
<dt id="pg.set_namedresult">
<code class="descclassname">pg.</code><code class="descname">set_namedresult</code><span class="sig-paren">(</span><em>func</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_namedresult" title="Permalink to this definition">¶</a></dt>
<dd><p>Set a function that will convert to named tuples</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>func</strong> – the function to be used to convert results to named tuples</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>You can use this if you want to create different kinds of named tuples
returned by the <a class="reference internal" href="query.html#pg.Query.namedresult" title="pg.Query.namedresult"><code class="xref py py-meth docutils literal"><span class="pre">Query.namedresult()</span></code></a> method. If you set this function
to <em>None</em>, then it will become equal to <a class="reference internal" href="query.html#pg.Query.getresult" title="pg.Query.getresult"><code class="xref py py-meth docutils literal"><span class="pre">Query.getresult()</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 4.1.</span></p>
</div>
</div>
<div class="section" id="get-set-decimal-decimal-type-to-be-used-for-numeric-values">
<h2>get/set_decimal – decimal type to be used for numeric values<a class="headerlink" href="#get-set-decimal-decimal-type-to-be-used-for-numeric-values" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_decimal">
<code class="descclassname">pg.</code><code class="descname">get_decimal</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_decimal" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the decimal type to be used for numeric values</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">the Python class used for PostgreSQL numeric values</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">class</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function returns the Python class that is used by PyGreSQL to hold
PostgreSQL numeric values. The default class is <code class="xref py py-class docutils literal"><span class="pre">decimal.Decimal</span></code>
if available, otherwise the <code class="xref py py-class docutils literal"><span class="pre">float</span></code> type is used.</p>
<dl class="function">
<dt id="pg.set_decimal">
<code class="descclassname">pg.</code><code class="descname">set_decimal</code><span class="sig-paren">(</span><em>cls</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_decimal" title="Permalink to this definition">¶</a></dt>
<dd><p>Set a decimal type to be used for numeric values</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>cls</strong> (<em>class</em>) – the Python class to be used for PostgreSQL numeric values</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function can be used to specify the Python class that shall
be used by PyGreSQL to hold PostgreSQL numeric values.
The default class is <code class="xref py py-class docutils literal"><span class="pre">decimal.Decimal</span></code> if available,
otherwise the <code class="xref py py-class docutils literal"><span class="pre">float</span></code> type is used.</p>
</div>
<div class="section" id="get-set-decimal-point-decimal-mark-used-for-monetary-values">
<h2>get/set_decimal_point – decimal mark used for monetary values<a class="headerlink" href="#get-set-decimal-point-decimal-mark-used-for-monetary-values" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_decimal_point">
<code class="descclassname">pg.</code><code class="descname">get_decimal_point</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_decimal_point" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the decimal mark used for monetary values</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">string with one character representing the decimal mark</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">str</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function returns the decimal mark used by PyGreSQL to interpret
PostgreSQL monetary values when converting them to decimal numbers.
The default setting is <code class="docutils literal"><span class="pre">'.'</span></code> as a decimal point. This setting is not
adapted automatically to the locale used by PostGreSQL, but you can use
<a class="reference internal" href="#pg.set_decimal" title="pg.set_decimal"><code class="xref py py-func docutils literal"><span class="pre">set_decimal()</span></code></a> to set a different decimal mark manually. A return
value of <code class="docutils literal"><span class="pre">None</span></code> means monetary values are not interpreted as decimal
numbers, but returned as strings including the formatting and currency.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 4.1.1.</span></p>
</div>
<dl class="function">
<dt id="pg.set_decimal_point">
<code class="descclassname">pg.</code><code class="descname">set_decimal_point</code><span class="sig-paren">(</span><em>string</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_decimal_point" title="Permalink to this definition">¶</a></dt>
<dd><p>Specify which decimal mark is used for interpreting monetary values</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>string</strong> (<em>str</em>) – string with one character representing the decimal mark</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function can be used to specify the decimal mark used by PyGreSQL
to interpret PostgreSQL monetary values. The default value is ‘.’ as
a decimal point. This value is not adapted automatically to the locale
used by PostGreSQL, so if you are dealing with a database set to a
locale that uses a <code class="docutils literal"><span class="pre">','</span></code> instead of <code class="docutils literal"><span class="pre">'.'</span></code> as the decimal point,
then you need to call <code class="docutils literal"><span class="pre">set_decimal(',')</span></code> to have PyGreSQL interpret
monetary values correctly. If you don’t want money values to be converted
to decimal numbers, then you can call <code class="docutils literal"><span class="pre">set_decimal(None)</span></code>, which will
cause PyGreSQL to return monetary values as strings including their
formatting and currency.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 4.1.1.</span></p>
</div>
</div>
<div class="section" id="get-set-bool-whether-boolean-values-are-returned-as-bool-objects">
<h2>get/set_bool – whether boolean values are returned as bool objects<a class="headerlink" href="#get-set-bool-whether-boolean-values-are-returned-as-bool-objects" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_bool">
<code class="descclassname">pg.</code><code class="descname">get_bool</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_bool" title="Permalink to this definition">¶</a></dt>
<dd><p>Check whether boolean values are returned as bool objects</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">whether or not bool objects will be returned</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">bool</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function checks whether PyGreSQL returns PostgreSQL boolean
values converted to Python bool objects, or as <code class="docutils literal"><span class="pre">'f'</span></code> and <code class="docutils literal"><span class="pre">'t'</span></code>
strings which are the values used internally by PostgreSQL. By default,
conversion to bool objects is activated, but you can disable this with
the <a class="reference internal" href="#pg.set_bool" title="pg.set_bool"><code class="xref py py-func docutils literal"><span class="pre">set_bool()</span></code></a> function.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 4.2.</span></p>
</div>
<dl class="function">
<dt id="pg.set_bool">
<code class="descclassname">pg.</code><code class="descname">set_bool</code><span class="sig-paren">(</span><em>on</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_bool" title="Permalink to this definition">¶</a></dt>
<dd><p>Set whether boolean values are returned as bool objects</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>on</strong> – whether or not bool objects shall be returned</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function can be used to specify whether PyGreSQL shall return
PostgreSQL boolean values converted to Python bool objects, or as
<code class="docutils literal"><span class="pre">'f'</span></code> and <code class="docutils literal"><span class="pre">'t'</span></code> strings which are the values used internally by
PostgreSQL. By default, conversion to bool objects is activated,
but you can disable this by calling <code class="docutils literal"><span class="pre">set_bool(True)</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 4.2.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 5.0: </span>Boolean values had been returned as string by default in earlier versions.</p>
</div>
</div>
<div class="section" id="get-set-array-whether-arrays-are-returned-as-list-objects">
<h2>get/set_array – whether arrays are returned as list objects<a class="headerlink" href="#get-set-array-whether-arrays-are-returned-as-list-objects" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_array">
<code class="descclassname">pg.</code><code class="descname">get_array</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_array" title="Permalink to this definition">¶</a></dt>
<dd><p>Check whether arrays are returned as list objects</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">whether or not list objects will be returned</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">bool</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function checks whether PyGreSQL returns PostgreSQL arrays converted
to Python list objects, or simply as text in the internal special output
syntax of PostgreSQL. By default, conversion to list objects is activated,
but you can disable this with the <a class="reference internal" href="#pg.set_array" title="pg.set_array"><code class="xref py py-func docutils literal"><span class="pre">set_array()</span></code></a> function.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<dl class="function">
<dt id="pg.set_array">
<code class="descclassname">pg.</code><code class="descname">set_array</code><span class="sig-paren">(</span><em>on</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_array" title="Permalink to this definition">¶</a></dt>
<dd><p>Set whether arrays are returned as list objects</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>on</strong> – whether or not list objects shall be returned</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function can be used to specify whether PyGreSQL shall return PostgreSQL
arrays converted to Python list objects, or simply as text in the internal
special output syntax of PostgreSQL. By default, conversion to list objects
is activated, but you can disable this by calling <code class="docutils literal"><span class="pre">set_array(False)</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 5.0: </span>Arrays had been always returned as text strings only in earlier versions.</p>
</div>
</div>
<div class="section" id="get-set-bytea-escaped-whether-bytea-data-is-returned-escaped">
<h2>get/set_bytea_escaped – whether bytea data is returned escaped<a class="headerlink" href="#get-set-bytea-escaped-whether-bytea-data-is-returned-escaped" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_bytea_escaped">
<code class="descclassname">pg.</code><code class="descname">get_bytea_escaped</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_bytea_escaped" title="Permalink to this definition">¶</a></dt>
<dd><p>Check whether bytea values are returned as escaped strings</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">whether or not bytea objects will be returned escaped</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">bool</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function checks whether PyGreSQL returns PostgreSQL <code class="docutils literal"><span class="pre">bytea</span></code> values in
escaped form or in unescaped from as byte strings. By default, bytea values
will be returned unescaped as byte strings, but you can change this with the
<a class="reference internal" href="#pg.set_bytea_escaped" title="pg.set_bytea_escaped"><code class="xref py py-func docutils literal"><span class="pre">set_bytea_escaped()</span></code></a> function.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<dl class="function">
<dt id="pg.set_bytea_escaped">
<code class="descclassname">pg.</code><code class="descname">set_bytea_escaped</code><span class="sig-paren">(</span><em>on</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_bytea_escaped" title="Permalink to this definition">¶</a></dt>
<dd><p>Set whether bytea values are returned as escaped strings</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>on</strong> – whether or not bytea objects shall be returned escaped</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function can be used to specify whether PyGreSQL shall return
PostgreSQL <code class="docutils literal"><span class="pre">bytea</span></code> values in escaped form or in unescaped from as byte
strings. By default, bytea values will be returned unescaped as byte
strings, but you can change this by calling <code class="docutils literal"><span class="pre">set_bytea_escaped(True)</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 5.0: </span>Bytea data had been returned in escaped form by default in earlier versions.</p>
</div>
</div>
<div class="section" id="get-set-jsondecode-decoding-json-format">
<h2>get/set_jsondecode – decoding JSON format<a class="headerlink" href="#get-set-jsondecode-decoding-json-format" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_jsondecode">
<code class="descclassname">pg.</code><code class="descname">get_jsondecode</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_jsondecode" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the function that deserializes JSON formatted strings</p>
</dd></dl>
<p>This returns the function used by PyGreSQL to construct Python objects
from JSON formatted strings.</p>
<dl class="function">
<dt id="pg.set_jsondecode">
<code class="descclassname">pg.</code><code class="descname">set_jsondecode</code><span class="sig-paren">(</span><em>func</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_jsondecode" title="Permalink to this definition">¶</a></dt>
<dd><p>Set a function that will deserialize JSON formatted strings</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>func</strong> – the function to be used for deserializing JSON strings</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>You can use this if you do not want to deserialize JSON strings coming
in from the database, or if want to use a different function than the
standard function <code class="xref py py-func docutils literal"><span class="pre">json.loads()</span></code> or if you want to use it with parameters
different from the default ones. If you set this function to <em>None</em>, then
the automatic deserialization of JSON strings will be deactivated.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 5.0: </span>JSON data had been always returned as text strings in earlier versions.</p>
</div>
</div>
<div class="section" id="get-set-cast-hook-fallback-typecast-function">
<h2>get/set_cast_hook – fallback typecast function<a class="headerlink" href="#get-set-cast-hook-fallback-typecast-function" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_cast_hook">
<code class="descclassname">pg.</code><code class="descname">get_cast_hook</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_cast_hook" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the function that handles all external typecasting</p>
</dd></dl>
<p>This returns the callback function used by PyGreSQL to provide plug-in
Python typecast functions.</p>
<dl class="function">
<dt id="pg.set_cast_hook">
<code class="descclassname">pg.</code><code class="descname">set_cast_hook</code><span class="sig-paren">(</span><em>func</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_cast_hook" title="Permalink to this definition">¶</a></dt>
<dd><p>Set a function that will handle all external typecasting</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>func</strong> – the function to be used as a callback</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>If you set this function to <em>None</em>, then only the typecast functions
implemented in the C extension module are enabled. You normally would
not want to change this. Instead, you can use <a class="reference internal" href="#pg.get_typecast" title="pg.get_typecast"><code class="xref py py-func docutils literal"><span class="pre">get_typecast()</span></code></a> and
<a class="reference internal" href="#pg.set_typecast" title="pg.set_typecast"><code class="xref py py-func docutils literal"><span class="pre">set_typecast()</span></code></a> to add or change the plug-in Python typecast functions.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
</div>
<div class="section" id="get-set-datestyle-assume-a-fixed-date-style">
<h2>get/set_datestyle – assume a fixed date style<a class="headerlink" href="#get-set-datestyle-assume-a-fixed-date-style" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pg.get_datestyle">
<code class="descclassname">pg.</code><code class="descname">get_datestyle</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_datestyle" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the assumed date style for typecasting</p>
</dd></dl>
<p>This returns the PostgreSQL date style that is silently assumed when
typecasting dates or <em>None</em> if no fixed date style is assumed, in which case
the date style is requested from the database when necessary (this is the
default). Note that this method will <em>not</em> get the date style that is
currently set in the session or in the database. You can get the current
setting with the methods <a class="reference internal" href="db_wrapper.html#pg.DB.get_parameter" title="pg.DB.get_parameter"><code class="xref py py-meth docutils literal"><span class="pre">DB.get_parameter()</span></code></a> and
<a class="reference internal" href="connection.html#pg.Connection.parameter" title="pg.Connection.parameter"><code class="xref py py-meth docutils literal"><span class="pre">Connection.parameter()</span></code></a>. You can also get the date format corresponding
to the current date style by calling <a class="reference internal" href="connection.html#pg.Connection.date_format" title="pg.Connection.date_format"><code class="xref py py-meth docutils literal"><span class="pre">Connection.date_format()</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<dl class="function">
<dt id="pg.set_datestyle">
<code class="descclassname">pg.</code><code class="descname">set_datestyle</code><span class="sig-paren">(</span><em>datestyle</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_datestyle" title="Permalink to this definition">¶</a></dt>
<dd><p>Set a fixed date style that shall be assumed when typecasting</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>datestyle</strong> (<em>str</em>) – the date style that shall be assumed,
or <em>None</em> if no fixed dat style shall be assumed</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>PyGreSQL is able to automatically pick up the right date style for typecasting
date values from the database, even if you change it for the current session
with a <code class="docutils literal"><span class="pre">SET</span> <span class="pre">DateStyle</span></code> command. This is happens very effectively without
an additional database request being involved. If you still want to have
PyGreSQL always assume a fixed date style instead, then you can set one with
this function. Note that calling this function will <em>not</em> alter the date
style of the database or the current session. You can do that by calling
the method <a class="reference internal" href="db_wrapper.html#pg.DB.set_parameter" title="pg.DB.set_parameter"><code class="xref py py-meth docutils literal"><span class="pre">DB.set_parameter()</span></code></a> instead.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
</div>
<div class="section" id="get-set-typecast-custom-typecasting">
<h2>get/set_typecast – custom typecasting<a class="headerlink" href="#get-set-typecast-custom-typecasting" title="Permalink to this headline">¶</a></h2>
<p>PyGreSQL uses typecast functions to cast the raw data coming from the
database to Python objects suitable for the particular database type.
These functions take a single string argument that represents the data
to be casted and must return the casted value.</p>
<p>PyGreSQL provides through its C extension module basic typecast functions
for the common database types, but if you want to add more typecast functions,
you can set these using the following functions.</p>
<dl class="method">
<dt id="pg.get_typecast">
<code class="descclassname">pg.</code><code class="descname">get_typecast</code><span class="sig-paren">(</span><em>typ</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.get_typecast" title="Permalink to this definition">¶</a></dt>
<dd><p>Get the global cast function for the given database type</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>typ</strong> (<em>str</em>) – PostgreSQL type name</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body">the typecast function for the specified type</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">function or None</td>
</tr>
</tbody>
</table>
</dd></dl>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<dl class="method">
<dt id="pg.set_typecast">
<code class="descclassname">pg.</code><code class="descname">set_typecast</code><span class="sig-paren">(</span><em>typ</em>, <em>cast</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.set_typecast" title="Permalink to this definition">¶</a></dt>
<dd><p>Set a global typecast function for the given database type(s)</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
<li><strong>typ</strong> (<em>str or int</em>) – PostgreSQL type name or list of type names</li>
<li><strong>cast</strong> – the typecast function to be set for the specified type(s)</li>
</ul>
</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>The typecast function must take one string object as argument and return a
Python object into which the PostgreSQL type shall be casted. If the function
takes another parameter named <em>connection</em>, then the current database
connection will also be passed to the typecast function. This may sometimes
be necessary to look up certain database settings.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<p>Note that database connections cache types and their cast functions using
connection specific <a class="reference internal" href="db_types.html#pg.DbTypes" title="pg.DbTypes"><code class="xref py py-class docutils literal"><span class="pre">DbTypes</span></code></a> objects. You can also get, set and
reset typecast functions on the connection level using the methods
<a class="reference internal" href="db_types.html#pg.DbTypes.get_typecast" title="pg.DbTypes.get_typecast"><code class="xref py py-meth docutils literal"><span class="pre">DbTypes.get_typecast()</span></code></a>, <a class="reference internal" href="db_types.html#pg.DbTypes.set_typecast" title="pg.DbTypes.set_typecast"><code class="xref py py-meth docutils literal"><span class="pre">DbTypes.set_typecast()</span></code></a> and
<a class="reference internal" href="db_types.html#pg.DbTypes.reset_typecast" title="pg.DbTypes.reset_typecast"><code class="xref py py-meth docutils literal"><span class="pre">DbTypes.reset_typecast()</span></code></a> of the <a class="reference internal" href="db_wrapper.html#pg.DB.dbtypes" title="pg.DB.dbtypes"><code class="xref py py-attr docutils literal"><span class="pre">DB.dbtypes</span></code></a> object. This will
not affect other connections or future connections. In order to be sure
a global change is picked up by a running connection, you must reopen it or
call <a class="reference internal" href="db_types.html#pg.DbTypes.reset_typecast" title="pg.DbTypes.reset_typecast"><code class="xref py py-meth docutils literal"><span class="pre">DbTypes.reset_typecast()</span></code></a> on the <a class="reference internal" href="db_wrapper.html#pg.DB.dbtypes" title="pg.DB.dbtypes"><code class="xref py py-attr docutils literal"><span class="pre">DB.dbtypes</span></code></a> object.</p>
<p>Also note that the typecasting for all of the basic types happens already
in the C extension module. The typecast functions that can be set with
the above methods are only called for the types that are not already
supported by the C extension module.</p>
</div>
<div class="section" id="cast-array-record-fast-parsers-for-arrays-and-records">
<h2>cast_array/record – fast parsers for arrays and records<a class="headerlink" href="#cast-array-record-fast-parsers-for-arrays-and-records" title="Permalink to this headline">¶</a></h2>
<p>PosgreSQL returns arrays and records (composite types) using a special output
syntax with several quirks that cannot easily and quickly be parsed in Python.
Therefore the C extension module provides two fast parsers that allow quickly
turning these text representations into Python objects: Arrays will be
converted to Python lists, and records to Python tuples. These fast parsers
are used automatically by PyGreSQL in order to return arrays and records from
database queries as lists and tuples, so you normally don’t need to call them
directly. You may only need them for typecasting arrays of data types that
are not supported by default in PostgreSQL.</p>
<dl class="function">
<dt id="pg.cast_array">
<code class="descclassname">pg.</code><code class="descname">cast_array</code><span class="sig-paren">(</span><em>string</em><span class="optional">[</span>, <em>cast</em><span class="optional">]</span><span class="optional">[</span>, <em>delim</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.cast_array" title="Permalink to this definition">¶</a></dt>
<dd><p>Cast a string representing a PostgreSQL array to a Python list</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>string</strong> (<em>str</em>) – the string with the text representation of the array</li>
<li><strong>cast</strong> (<em>callable or None</em>) – a typecast function for the elements of the array</li>
<li><strong>delim</strong> – delimiter character between adjacent elements</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">a list representing the PostgreSQL array in Python</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first">list</p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><ul class="first last simple">
<li><strong>TypeError</strong> – invalid argument types</li>
<li><strong>ValueError</strong> – error in the syntax of the given array</li>
</ul>
</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function takes a <em>string</em> containing the text representation of a
PostgreSQL array (which may look like <code class="docutils literal"><span class="pre">'{{1,2}{3,4}}'</span></code> for a two-dimensional
array), a typecast function <em>cast</em> that is called for every element, and
an optional delimiter character <em>delim</em> (usually a comma), and returns a
Python list representing the array (which may be nested like
<code class="docutils literal"><span class="pre">[[1,</span> <span class="pre">2],</span> <span class="pre">[3,</span> <span class="pre">4]]</span></code> in this example). The cast function must take a single
argument which will be the text representation of the element and must output
the corresponding Python object that shall be put into the list. If you don’t
pass a cast function or set it to <em>None</em>, then unprocessed text strings will
be returned as elements of the array. If you don’t pass a delimiter character,
then a comma will be used by default.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<dl class="function">
<dt id="pg.cast_record">
<code class="descclassname">pg.</code><code class="descname">cast_record</code><span class="sig-paren">(</span><em>string</em><span class="optional">[</span>, <em>cast</em><span class="optional">]</span><span class="optional">[</span>, <em>delim</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#pg.cast_record" title="Permalink to this definition">¶</a></dt>
<dd><p>Cast a string representing a PostgreSQL record to a Python tuple</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>string</strong> (<em>str</em>) – the string with the text representation of the record</li>
<li><strong>cast</strong> (<em>callable, list or tuple of callables, or None</em>) – typecast function(s) for the elements of the record</li>
<li><strong>delim</strong> – delimiter character between adjacent elements</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">a tuple representing the PostgreSQL record in Python</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first">tuple</p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><ul class="first last simple">
<li><strong>TypeError</strong> – invalid argument types</li>
<li><strong>ValueError</strong> – error in the syntax of the given array</li>
</ul>
</td>
</tr>
</tbody>
</table>
</dd></dl>
<p>This function takes a <em>string</em> containing the text representation of a
PostgreSQL record (which may look like <code class="docutils literal"><span class="pre">'(1,a,2,b)'</span></code> for a record composed
of four fields), a typecast function <em>cast</em> that is called for every element,
or a list or tuple of such functions corresponding to the individual fields
of the record, and an optional delimiter character <em>delim</em> (usually a comma),
and returns a Python tuple representing the record (which may be inhomogeneous
like <code class="docutils literal"><span class="pre">(1,</span> <span class="pre">'a',</span> <span class="pre">2,</span> <span class="pre">'b')</span></code> in this example). The cast function(s) must take a
single argument which will be the text representation of the element and must
output the corresponding Python object that shall be put into the tuple. If
you don’t pass cast function(s) or pass <em>None</em> instead, then unprocessed text
strings will be returned as elements of the tuple. If you don’t pass a
delimiter character, then a comma will be used by default.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<p>Note that besides using parentheses instead of braces, there are other subtle
differences in escaping special characters and NULL values between the syntax
used for arrays and the one used for composite types, which these functions
take into account.</p>
</div>
<div class="section" id="type-helpers">
<h2>Type helpers<a class="headerlink" href="#type-helpers" title="Permalink to this headline">¶</a></h2>
<p>The module provides the following type helper functions. You can wrap
parameters with these functions when passing them to <a class="reference internal" href="db_wrapper.html#pg.DB.query" title="pg.DB.query"><code class="xref py py-meth docutils literal"><span class="pre">DB.query()</span></code></a>
or <a class="reference internal" href="db_wrapper.html#pg.DB.query_formatted" title="pg.DB.query_formatted"><code class="xref py py-meth docutils literal"><span class="pre">DB.query_formatted()</span></code></a> in order to give PyGreSQL a hint about the
type of the parameters, if it cannot be derived from the context.</p>
<dl class="function">
<dt id="pg.Bytea">
<code class="descclassname">pg.</code><code class="descname">Bytea</code><span class="sig-paren">(</span><em>bytes</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.Bytea" title="Permalink to this definition">¶</a></dt>
<dd><p>A wrapper for holding a bytea value</p>
</dd></dl>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<dl class="function">
<dt id="pg.HStore">
<code class="descclassname">pg.</code><code class="descname">HStore</code><span class="sig-paren">(</span><em>dict</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.HStore" title="Permalink to this definition">¶</a></dt>
<dd><p>A wrapper for holding an hstore dictionary</p>
</dd></dl>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<dl class="function">
<dt id="pg.Json">
<code class="descclassname">pg.</code><code class="descname">Json</code><span class="sig-paren">(</span><em>obj</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.Json" title="Permalink to this definition">¶</a></dt>
<dd><p>A wrapper for holding an object serializable to JSON</p>
</dd></dl>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
<p>The following additional type helper is only meaningful when used with
<a class="reference internal" href="db_wrapper.html#pg.DB.query_formatted" title="pg.DB.query_formatted"><code class="xref py py-meth docutils literal"><span class="pre">DB.query_formatted()</span></code></a>. It marks a parameter as text that shall be
literally included into the SQL. This is useful for passing table names
for instance.</p>
<dl class="function">
<dt id="pg.Literal">
<code class="descclassname">pg.</code><code class="descname">Literal</code><span class="sig-paren">(</span><em>sql</em><span class="sig-paren">)</span><a class="headerlink" href="#pg.Literal" title="Permalink to this definition">¶</a></dt>
<dd><p>A wrapper for holding a literal SQL string</p>
</dd></dl>
<div class="versionadded">
<p><span class="versionmodified">New in version 5.0.</span></p>
</div>
</div>
<div class="section" id="module-constants">
<h2>Module constants<a class="headerlink" href="#module-constants" title="Permalink to this headline">¶</a></h2>
<p>Some constants are defined in the module dictionary.
They are intended to be used as parameters for methods calls.
You should refer to the libpq description in the PostgreSQL user manual
for more information about them. These constants are:</p>
<dl class="data">
<dt id="pg.version">
<code class="descclassname">pg.</code><code class="descname">version</code><a class="headerlink" href="#pg.version" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="data">
<dt id="pg.__version__">
<code class="descclassname">pg.</code><code class="descname">__version__</code><a class="headerlink" href="#pg.__version__" title="Permalink to this definition">¶</a></dt>
<dd><p>constants that give the current version</p>
</dd></dl>
<dl class="data">
<dt id="pg.INV_READ">
<code class="descclassname">pg.</code><code class="descname">INV_READ</code><a class="headerlink" href="#pg.INV_READ" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="data">
<dt id="pg.INV_WRITE">
<code class="descclassname">pg.</code><code class="descname">INV_WRITE</code><a class="headerlink" href="#pg.INV_WRITE" title="Permalink to this definition">¶</a></dt>
<dd><p>large objects access modes,
used by <a class="reference internal" href="connection.html#pg.Connection.locreate" title="pg.Connection.locreate"><code class="xref py py-meth docutils literal"><span class="pre">Connection.locreate()</span></code></a> and <a class="reference internal" href="large_objects.html#pg.LargeObject.open" title="pg.LargeObject.open"><code class="xref py py-meth docutils literal"><span class="pre">LargeObject.open()</span></code></a></p>
</dd></dl>
<dl class="data">
<dt id="pg.SEEK_SET">
<code class="descclassname">pg.</code><code class="descname">SEEK_SET</code><a class="headerlink" href="#pg.SEEK_SET" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="data">
<dt id="pg.SEEK_CUR">
<code class="descclassname">pg.</code><code class="descname">SEEK_CUR</code><a class="headerlink" href="#pg.SEEK_CUR" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="data">
<dt id="pg.SEEK_END">
<code class="descclassname">pg.</code><code class="descname">SEEK_END</code><a class="headerlink" href="#pg.SEEK_END" title="Permalink to this definition">¶</a></dt>
<dd><p>positional flags, used by <a class="reference internal" href="large_objects.html#pg.LargeObject.seek" title="pg.LargeObject.seek"><code class="xref py py-meth docutils literal"><span class="pre">LargeObject.seek()</span></code></a></p>
</dd></dl>
<dl class="data">
<dt id="pg.TRANS_IDLE">
<code class="descclassname">pg.</code><code class="descname">TRANS_IDLE</code><a class="headerlink" href="#pg.TRANS_IDLE" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="data">
<dt id="pg.TRANS_ACTIVE">
<code class="descclassname">pg.</code><code class="descname">TRANS_ACTIVE</code><a class="headerlink" href="#pg.TRANS_ACTIVE" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="data">
<dt id="pg.TRANS_INTRANS">
<code class="descclassname">pg.</code><code class="descname">TRANS_INTRANS</code><a class="headerlink" href="#pg.TRANS_INTRANS" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="data">
<dt id="pg.TRANS_INERROR">
<code class="descclassname">pg.</code><code class="descname">TRANS_INERROR</code><a class="headerlink" href="#pg.TRANS_INERROR" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="data">
<dt id="pg.TRANS_UNKNOWN">
<code class="descclassname">pg.</code><code class="descname">TRANS_UNKNOWN</code><a class="headerlink" href="#pg.TRANS_UNKNOWN" title="Permalink to this definition">¶</a></dt>
<dd><p>transaction states, used by <a class="reference internal" href="connection.html#pg.Connection.transaction" title="pg.Connection.transaction"><code class="xref py py-meth docutils literal"><span class="pre">Connection.transaction()</span></code></a></p>
</dd></dl>
</div>
</div>
</div>
</div>
</div>
<div class="sphinxsidebar" role="navigation" aria-label="main navigation">
<div class="sphinxsidebarwrapper">
<p class="logo"><a href="../index.html" title="contents/index">
<img class="logo" src="../../_static/pygresql.png" alt="Logo"/>
</a></p><div class="sphinxlocaltoc">
<h3><a href="../../index.html">Page contents</a></h3>
<ul>
<li><a class="reference internal" href="#">Module functions and constants</a><ul>
<li><a class="reference internal" href="#connect-open-a-postgresql-connection">connect – Open a PostgreSQL connection</a></li>
<li><a class="reference internal" href="#get-set-defhost-default-server-host-dv">get/set_defhost – default server host [DV]</a></li>
<li><a class="reference internal" href="#get-set-defport-default-server-port-dv">get/set_defport – default server port [DV]</a></li>
<li><a class="reference internal" href="#get-set-defopt-default-connection-options-dv">get/set_defopt – default connection options [DV]</a></li>
<li><a class="reference internal" href="#get-set-defbase-default-database-name-dv">get/set_defbase – default database name [DV]</a></li>
<li><a class="reference internal" href="#get-set-defuser-default-database-user-dv">get/set_defuser – default database user [DV]</a></li>
<li><a class="reference internal" href="#get-set-defpasswd-default-database-password-dv">get/set_defpasswd – default database password [DV]</a></li>
<li><a class="reference internal" href="#escape-string-escape-a-string-for-use-within-sql">escape_string – escape a string for use within SQL</a></li>
<li><a class="reference internal" href="#escape-bytea-escape-binary-data-for-use-within-sql">escape_bytea – escape binary data for use within SQL</a></li>
<li><a class="reference internal" href="#unescape-bytea-unescape-data-that-has-been-retrieved-as-text">unescape_bytea – unescape data that has been retrieved as text</a></li>
<li><a class="reference internal" href="#get-set-namedresult-conversion-to-named-tuples">get/set_namedresult – conversion to named tuples</a></li>
<li><a class="reference internal" href="#get-set-decimal-decimal-type-to-be-used-for-numeric-values">get/set_decimal – decimal type to be used for numeric values</a></li>
<li><a class="reference internal" href="#get-set-decimal-point-decimal-mark-used-for-monetary-values">get/set_decimal_point – decimal mark used for monetary values</a></li>
<li><a class="reference internal" href="#get-set-bool-whether-boolean-values-are-returned-as-bool-objects">get/set_bool – whether boolean values are returned as bool objects</a></li>
<li><a class="reference internal" href="#get-set-array-whether-arrays-are-returned-as-list-objects">get/set_array – whether arrays are returned as list objects</a></li>
<li><a class="reference internal" href="#get-set-bytea-escaped-whether-bytea-data-is-returned-escaped">get/set_bytea_escaped – whether bytea data is returned escaped</a></li>
<li><a class="reference internal" href="#get-set-jsondecode-decoding-json-format">get/set_jsondecode – decoding JSON format</a></li>
<li><a class="reference internal" href="#get-set-cast-hook-fallback-typecast-function">get/set_cast_hook – fallback typecast function</a></li>
<li><a class="reference internal" href="#get-set-datestyle-assume-a-fixed-date-style">get/set_datestyle – assume a fixed date style</a></li>
<li><a class="reference internal" href="#get-set-typecast-custom-typecasting">get/set_typecast – custom typecasting</a></li>
<li><a class="reference internal" href="#cast-array-record-fast-parsers-for-arrays-and-records">cast_array/record – fast parsers for arrays and records</a></li>
<li><a class="reference internal" href="#type-helpers">Type helpers</a></li>
<li><a class="reference internal" href="#module-constants">Module constants</a></li>
</ul>
</li>
</ul>
</div>
<div class="sphinxprev">
<h4>Previous page</h4>
<p class="topless"><a href="introduction.html"
title="Previous page">← Introduction</a></p>
</div>
<div class="sphinxnext">
<h4>Next page</h4>
<p class="topless"><a href="connection.html"
title="Next page">→ Connection – The connection object</a></p>
</div>
<div role="note" aria-label="source link">
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="../../_sources/contents/pg/module.txt"
rel="nofollow">Show Source</a></li>
</ul>
</div>
<div id="searchbox" style="display: none" role="search">
<h3>Quick search</h3>
<form class="search" action="../../search.html" method="get">
<input type="text" name="q" />
<input type="submit" value="Go" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
<script type="text/javascript">$('#searchbox').show(0);</script>
</div>
</div>
<div class="clearer"></div>
</div>
<div class="relbar-bottom">
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="../../genindex.html" title="General Index"
>index</a></li>
<li class="right" >
<a href="../../py-modindex.html" title="Python Module Index"
>modules</a> </li>
<li class="right" >
<a href="connection.html" title="Connection – The connection object"
>next</a> </li>
<li class="right" >
<a href="introduction.html" title="Introduction"
>previous</a> </li>
<li><a href="../index.html">PyGreSQL 5.0 documentation</a> »</li>
<li class="nav-item nav-item-1"><a href="index.html" ><code class="docutils literal"><span class="pre">pg</span></code> — The Classic PyGreSQL Interface</a> »</li>
</ul>
</div>
</div>
<div class="footer" role="contentinfo">
© <a href="../../copyright.html">Copyright</a> 2016, The PyGreSQL team.
Created using <a href="http://sphinx-doc.org/">Sphinx</a> 1.4.1.
</div>
<!-- cloud_sptheme 1.4 -->
</body>
</html>
|
