summaryrefslogtreecommitdiffstats
path: root/Misc/python-mode-old.el
blob: 76b391c5980bd1eb1c0a24b499ebfbae704dc2e1 (plain)
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
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
;;; Major mode for editing Python programs, version 1.10
;; by: Tim Peters <tim@ksr.com>
;; after an original idea by: Michael A. Guravage
;;
;; Copyright (c) 1992,1993,1994  Tim Peters
;;
;; This software is provided as-is, without express or implied warranty.
;; Permission to use, copy, modify, distribute or sell this software,
;; without fee, for any purpose and by any individual or organization, is
;; hereby granted, provided that the above copyright notice and this
;; paragraph appear in all copies.
;;
;;
;; The following statements, placed in your .emacs file or site-init.el,
;; will cause this file to be autoloaded, and python-mode invoked, when
;; visiting .py files (assuming the file is in your load-path):
;;
;;	(autoload 'python-mode "python-mode" "" t)
;;	(setq auto-mode-alist
;;	      (cons '("\\.py$" . python-mode) auto-mode-alist))

(provide 'python-mode)

;;; Differentiate between Emacs 18, Lucid Emacs, and Emacs 19.
;;; This seems to be the standard way of checking this.

(setq py-this-is-lucid-emacs-p (string-match "Lucid" emacs-version))
(setq py-this-is-emacs-19-p
      (and
       (not py-this-is-lucid-emacs-p)
       (string-match "^19\\." emacs-version)))

;;; Constants and variables

(defvar py-python-command "python"
  "*Shell command used to start Python interpreter.")

(defvar py-indent-offset 8		; argue with Guido <grin>
  "*Indentation increment.
Note that `\\[py-guess-indent-offset]' can usually guess a good value when you're
editing someone else's Python code.")

(defvar py-block-comment-prefix "##"
  "*String used by py-comment-region to comment out a block of code.
This should follow the convention for non-indenting comment lines so
that the indentation commands won't get confused (i.e., the string
should be of the form `#x...' where `x' is not a blank or a tab, and
`...' is arbitrary).")

(defvar py-scroll-process-buffer t
  "*Scroll Python process buffer as output arrives.
If nil, the Python process buffer acts, with respect to scrolling, like
Shell-mode buffers normally act.  This is surprisingly complicated and
so won't be explained here; in fact, you can't get the whole story
without studying the Emacs C code.

If non-nil, the behavior is different in two respects (which are
slightly inaccurate in the interest of brevity):

  - If the buffer is in a window, and you left point at its end, the
    window will scroll as new output arrives, and point will move to the
    buffer's end, even if the window is not the selected window (that
    being the one the cursor is in).  The usual behavior for shell-mode
    windows is not to scroll, and to leave point where it was, if the
    buffer is in a window other than the selected window.

  - If the buffer is not visible in any window, and you left point at
    its end, the buffer will be popped into a window as soon as more
    output arrives.  This is handy if you have a long-running
    computation and don't want to tie up screen area waiting for the
    output.  The usual behavior for a shell-mode buffer is to stay
    invisible until you explicitly visit it.

Note the `and if you left point at its end' clauses in both of the
above:  you can `turn off' the special behaviors while output is in
progress, by visiting the Python buffer and moving point to anywhere
besides the end.  Then the buffer won't scroll, point will remain where
you leave it, and if you hide the buffer it will stay hidden until you
visit it again.  You can enable and disable the special behaviors as
often as you like, while output is in progress, by (respectively) moving
point to, or away from, the end of the buffer.

Warning:  If you expect a large amount of output, you'll probably be
happier setting this option to nil.

Obscure:  `End of buffer' above should really say `at or beyond the
process mark', but if you know what that means you didn't need to be
told <grin>.")

(defvar py-temp-directory
  (let ( (ok '(lambda (x)
		(and x
		     (setq x (expand-file-name x)) ; always true
		     (file-directory-p x)
		     (file-writable-p x)
		     x))))
    (or (funcall ok (getenv "TMPDIR"))
	(funcall ok "/usr/tmp")
	(funcall ok "/tmp")
	(funcall ok  ".")
	(error
	 "Couldn't find a usable temp directory -- set py-temp-directory")))
  "*Directory used for temp files created by a *Python* process.
By default, the first directory from this list that exists and that you
can write into:  the value (if any) of the environment variable TMPDIR,
/usr/tmp, /tmp, or the current directory.")

;; have to bind py-file-queue before installing the kill-emacs hook
(defvar py-file-queue nil
  "Queue of Python temp files awaiting execution.
Currently-active file is at the head of the list.")

;; define a mode-specific abbrev table for those who use such things
(defvar python-mode-abbrev-table nil
  "Abbrev table in use in python-mode buffers.")
(define-abbrev-table 'python-mode-abbrev-table nil)

;; arrange to kill temp files no matter what
(if (or py-this-is-emacs-19-p py-this-is-lucid-emacs-p)
    (add-hook 'kill-emacs-hook 'py-kill-emacs-hook)
  ;; have to trust that other people are as respectful of our hook
  ;; fiddling as we are of theirs
  (if (boundp 'py-inherited-kill-emacs-hook)
      ;; we were loaded before -- trust others not to have screwed us
      ;; in the meantime (no choice, really)
      nil
    ;; else arrange for our hook to run theirs
    (setq py-inherited-kill-emacs-hook kill-emacs-hook)
    (setq kill-emacs-hook 'py-kill-emacs-hook)))

(defvar python-mode-hook nil
  "*Hook called by `python-mode'.")

(and (fboundp 'make-obsolete-variable)
     (make-obsolete-variable 'py-mode-hook 'python-mode-hook))

(defvar py-beep-if-tab-change t
  "*Ring the bell if tab-width is changed.
If a comment of the form
\t# vi:set tabsize=<number>:
is found before the first code line when the file is entered, and
the current value of (the general Emacs variable) tab-width does not
equal <number>, tab-width is set to <number>, a message saying so is
displayed in the echo area, and if py-beep-if-tab-change is non-nil the
Emacs bell is also rung as a warning.")

(defvar py-mode-map nil "Keymap used in Python mode buffers.")
(if py-mode-map
    ()
  (setq py-mode-map (make-sparse-keymap))

  ;; shadow global bindings for newline-and-indent w/ the py- version
  (mapcar (function (lambda (key)
		      (define-key
			py-mode-map key 'py-newline-and-indent)))
   (where-is-internal 'newline-and-indent))

  (mapcar (function
	   (lambda (x)
	     (define-key py-mode-map (car x) (cdr x))))
	  '( ("\C-c\C-c" . py-execute-buffer)
	     ("\C-c|"	 . py-execute-region)
	     ("\C-c!"	 . py-shell)
	     ("\177"	 . py-delete-char)
	     ("\n"	 . py-newline-and-indent)
	     ("\C-c:"	 . py-guess-indent-offset)
	     ("\C-c\t"	 . py-indent-region)
	     ("\C-c<"	 . py-shift-region-left)
	     ("\C-c>"	 . py-shift-region-right)
	     ("\C-c\C-n" . py-next-statement)
	     ("\C-c\C-p" . py-previous-statement)
	     ("\C-c\C-u" . py-goto-block-up)
	     ("\C-c\C-b" . py-mark-block)
	     ("\C-c#"	 . py-comment-region)
	     ("\C-c?"	 . py-describe-mode)
	     ("\C-c\C-hm" . py-describe-mode)
	     ("\e\C-a"	 . beginning-of-python-def-or-class)
	     ("\e\C-e"	 . end-of-python-def-or-class)
	     ( "\e\C-h"	 . mark-python-def-or-class))))

(defvar py-mode-syntax-table nil "Python mode syntax table")
(if py-mode-syntax-table
    ()
  (setq py-mode-syntax-table (make-syntax-table))
  (mapcar (function
	   (lambda (x) (modify-syntax-entry
			(car x) (cdr x) py-mode-syntax-table)))
	  '(( ?\( . "()" ) ( ?\) . ")(" )
	    ( ?\[ . "(]" ) ( ?\] . ")[" )
	    ( ?\{ . "(}" ) ( ?\} . "){" )
	    ;; fix operator symbols misassigned in the std table
	    ( ?\$ . "." ) ( ?\% . "." ) ( ?\& . "." )
	    ( ?\* . "." ) ( ?\+ . "." ) ( ?\- . "." )
	    ( ?\/ . "." ) ( ?\< . "." ) ( ?\= . "." )
	    ( ?\> . "." ) ( ?\| . "." )
	    ( ?\_ . "w" )	; underscore is legit in names
	    ( ?\' . "\"")	; single quote is string quote
	    ( ?\" . "\"" )	; double quote is string quote too
	    ( ?\` . "$")	; backquote is open and close paren
	    ( ?\# . "<")	; hash starts comment
	    ( ?\n . ">"))))	; newline ends comment

(defconst py-stringlit-re
  (concat
   "'\\([^'\n\\]\\|\\\\.\\)*'"		; single-quoted
   "\\|"				; or
   "\"\\([^\"\n\\]\\|\\\\.\\)*\"")	; double-quoted
  "regexp matching a Python string literal")

;; this is tricky because a trailing backslash does not mean
;; continuation if it's in a comment
(defconst py-continued-re
  (concat
   "\\(" "[^#'\"\n\\]" "\\|" py-stringlit-re "\\)*"
   "\\\\$")
  "regexp matching Python lines that are continued via backslash")

(defconst py-blank-or-comment-re "[ \t]*\\($\\|#\\)"
  "regexp matching blank or comment lines")

;;; General Functions

(defun python-mode ()
  "Major mode for editing Python files.
Do `\\[py-describe-mode]' for detailed documentation.
Knows about Python indentation, tokens, comments and continuation lines.
Paragraphs are separated by blank lines only.

COMMANDS
\\{py-mode-map}
VARIABLES

py-indent-offset\tindentation increment
py-block-comment-prefix\tcomment string used by py-comment-region
py-python-command\tshell command to invoke Python interpreter
py-scroll-process-buffer\talways scroll Python process buffer
py-temp-directory\tdirectory used for temp files (if needed)
py-beep-if-tab-change\tring the bell if tab-width is changed"
  (interactive)
  (kill-all-local-variables)
  (setq  major-mode 'python-mode
	 mode-name "Python"
	 local-abbrev-table python-mode-abbrev-table)
  (use-local-map py-mode-map)
  (set-syntax-table py-mode-syntax-table)

  (mapcar (function (lambda (x)
		      (make-local-variable (car x))
		      (set (car x) (cdr x))))
	  '( (paragraph-separate . "^[ \t]*$")
	     (paragraph-start	 . "^[ \t]*$")
	     (require-final-newline . t)
	     (comment-start .		"# ")
	     (comment-start-skip .	"# *")
	     (comment-column . 40)
	     (indent-region-function . py-indent-region)
	     (indent-line-function . py-indent-line)))

  ;; hack to allow overriding the tabsize in the file (see tokenizer.c)

  ;; not sure where the magic comment has to be; to save time searching
  ;; for a rarity, we give up if it's not found prior to the first
  ;; executable statement
  (let ( (case-fold-search nil)
	 (start (point))
	 new-tab-width)
    (if (re-search-forward
	 "^[ \t]*#[ \t]*vi:set[ \t]+tabsize=\\([0-9]+\\):"
	 (prog2 (py-next-statement 1) (point) (goto-char 1))
	 t)
	(progn
	  (setq new-tab-width
		(string-to-int
		 (buffer-substring (match-beginning 1) (match-end 1))))
	  (if (= tab-width new-tab-width)
	      nil
	    (setq tab-width new-tab-width)
	    (message "Caution: tab-width changed to %d" new-tab-width)
	    (if py-beep-if-tab-change (beep)))))
    (goto-char start))

  (if python-mode-hook
      (run-hooks 'python-mode-hook)
    (run-hooks 'py-mode-hook)))

;;; Functions that execute Python commands in a subprocess

(defun py-shell ()
  "Start an interactive Python interpreter in another window.
This is like Shell mode, except that Python is running in the window
instead of a shell.  See the `Interactive Shell' and `Shell Mode'
sections of the Emacs manual for details, especially for the key
bindings active in the `*Python*' buffer.

See the docs for variable py-scroll-buffer for info on scrolling
behavior in the process window.

Warning:  Don't use an interactive Python if you change sys.ps1 or
sys.ps2 from their default values, or if you're running code that prints
`>>> ' or `... ' at the start of a line.  Python mode can't distinguish
your output from Python's output, and assumes that `>>> ' at the start
of a line is a prompt from Python.  Similarly, the Emacs Shell mode code
assumes that both `>>> ' and `... ' at the start of a line are Python
prompts.  Bad things can happen if you fool either mode.

Warning:  If you do any editing *in* the process buffer *while* the
buffer is accepting output from Python, do NOT attempt to `undo' the
changes.  Some of the output (nowhere near the parts you changed!) may
be lost if you do.  This appears to be an Emacs bug, an unfortunate
interaction between undo and process filters; the same problem exists in
non-Python process buffers using the default (Emacs-supplied) process
filter."
  (interactive)
  (if py-this-is-emacs-19-p
      (progn
	(require 'comint)
	(switch-to-buffer-other-window
	 (make-comint "Python" py-python-command)))
    (progn
      (require 'shell)
      (switch-to-buffer-other-window
       (make-shell "Python" py-python-command))))
  (make-local-variable 'shell-prompt-pattern)
  (setq shell-prompt-pattern "^>>> \\|^\\.\\.\\. ")
  (set-process-filter (get-buffer-process (current-buffer))
		      'py-process-filter)
  (set-syntax-table py-mode-syntax-table))

(defun py-execute-region (start end)
  "Send the region between START and END to a Python interpreter.
If there is a *Python* process it is used.

Hint:  If you want to execute part of a Python file several times (e.g.,
perhaps you're developing a function and want to flesh it out a bit at a
time), use `\\[narrow-to-region]' to restrict the buffer to the region of interest,
and send the code to a *Python* process via `\\[py-execute-buffer]' instead.

Following are subtleties to note when using a *Python* process:

If a *Python* process is used, the region is copied into a temp file (in
directory py-temp-directory), and an `execfile' command is sent to
Python naming that file.  If you send regions faster than Python can
execute them, Python mode will save them into distinct temp files, and
execute the next one in the queue the next time it sees a `>>> ' prompt
from Python.  Each time this happens, the process buffer is popped into
a window (if it's not already in some window) so you can see it, and a
comment of the form

\t## working on region in file <name> ...

is inserted at the end.

Caution:  No more than 26 regions can be pending at any given time.  This
limit is (indirectly) inherited from libc's mktemp(3).  Python mode does
not try to protect you from exceeding the limit.  It's extremely
unlikely that you'll get anywhere close to the limit in practice, unless
you're trying to be a jerk <grin>.

See the `\\[py-shell]' docs for additional warnings."
  (interactive "r")
  (or (< start end) (error "Region is empty"))
  (let ( (pyproc (get-process "Python"))
 	 fname)
    (if (null pyproc)
	(shell-command-on-region start end py-python-command)
      ;; else feed it thru a temp file
      (setq fname (py-make-temp-name))
      (write-region start end fname nil 'no-msg)
      (setq py-file-queue (append py-file-queue (list fname)))
      (if (cdr py-file-queue)
	  (message "File %s queued for execution" fname)
	;; else
	(py-execute-file pyproc fname)))))

(defun py-execute-file (pyproc fname)
  (py-append-to-process-buffer
   pyproc
   (format "## working on region in file %s ...\n" fname))
  (process-send-string pyproc (format "execfile('%s')\n" fname)))

(defun py-process-filter (pyproc string)
  (let ( (curbuf (current-buffer))
	 (pbuf (process-buffer pyproc))
	 (pmark (process-mark pyproc))
	 file-finished)

    ;; make sure we switch to a different buffer at least once.  if we
    ;; *don't* do this, then if the process buffer is in the selected
    ;; window, and point is before the end, and lots of output is coming
    ;; at a fast pace, then (a) simple cursor-movement commands like
    ;; C-p, C-n, C-f, C-b, C-a, C-e take an incredibly long time to have
    ;; a visible effect (the window just doesn't get updated, sometimes
    ;; for minutes(!)), and (b) it takes about 5x longer to get all the
    ;; process output (until the next python prompt).
    ;;
    ;; #b makes no sense to me at all.  #a almost makes sense:  unless we
    ;; actually change buffers, set_buffer_internal in buffer.c doesn't
    ;; set windows_or_buffers_changed to 1, & that in turn seems to make
    ;; the Emacs command loop reluctant to update the display.  Perhaps
    ;; the default process filter in process.c's read_process_output has
    ;; update_mode_lines++ for a similar reason?  beats me ...
    (if (eq curbuf pbuf)		; mysterious ugly hack
	(set-buffer (get-buffer-create "*scratch*")))

    (set-buffer pbuf)
    (let* ( (start (point))
	    (goback (< start pmark))
	    (buffer-read-only nil))
      (goto-char pmark)
      (insert string)
      (move-marker pmark (point))
      (setq file-finished
	    (and py-file-queue
		 (equal ">>> "
			(buffer-substring
			 (prog2 (beginning-of-line) (point)
				(goto-char pmark))
			 (point)))))
      (if goback (goto-char start)
	;; else
	(if py-scroll-process-buffer
	    (let* ( (pop-up-windows t)
		    (pwin (display-buffer pbuf)))
	      (set-window-point pwin (point))))))
    (set-buffer curbuf)
    (if file-finished
	(progn
	  (py-delete-file-silently (car py-file-queue))
	  (setq py-file-queue (cdr py-file-queue))
	  (if py-file-queue
		(py-execute-file pyproc (car py-file-queue)))))))

(defun py-execute-buffer ()
  "Send the contents of the buffer to a Python interpreter.
If there is a *Python* process buffer it is used.  If a clipping
restriction is in effect, only the accessible portion of the buffer is
sent.  A trailing newline will be supplied if needed.

See the `\\[py-execute-region]' docs for an account of some subtleties."
  (interactive)
  (py-execute-region (point-min) (point-max)))


;;; Functions for Python style indentation

(defun py-delete-char ()
  "Reduce indentation or delete character.
If point is at the leftmost column, deletes the preceding newline.

Else if point is at the leftmost non-blank character of a line that is
neither a continuation line nor a non-indenting comment line, or if
point is at the end of a blank line, reduces the indentation to match
that of the line that opened the current block of code.  The line that
opened the block is displayed in the echo area to help you keep track of
where you are.

Else the preceding character is deleted, converting a tab to spaces if
needed so that only a single column position is deleted."
  (interactive "*")
  (if (or (/= (current-indentation) (current-column))
	  (bolp)
	  (py-continuation-line-p)
	  (looking-at "#[^ \t\n]"))	; non-indenting #
      (backward-delete-char-untabify 1)
    ;; else indent the same as the colon line that opened the block

    ;; force non-blank so py-goto-block-up doesn't ignore it
    (insert-char ?* 1)
    (backward-char)
    (let ( (base-indent 0)		; indentation of base line
	   (base-text "")		; and text of base line
	   (base-found-p nil))
      (condition-case nil		; in case no enclosing block
	  (save-excursion
	    (py-goto-block-up 'no-mark)
	    (setq base-indent (current-indentation)
		  base-text   (py-suck-up-leading-text)
		  base-found-p t))
	(error nil))
      (delete-char 1)			; toss the dummy character
      (delete-horizontal-space)
      (indent-to base-indent)
      (if base-found-p
	  (message "Closes block: %s" base-text)))))

(defun py-indent-line ()
  "Fix the indentation of the current line according to Python rules."
  (interactive)
  (let* ( (ci (current-indentation))
	  (move-to-indentation-p (<= (current-column) ci))
	  (need (py-compute-indentation)) )
    (if (/= ci need)
	(save-excursion
	  (beginning-of-line)
	  (delete-horizontal-space)
	  (indent-to need)))
    (if move-to-indentation-p (back-to-indentation))))

(defun py-newline-and-indent ()
  "Strives to act like the Emacs newline-and-indent.
This is just `strives to' because correct indentation can't be computed
from scratch for Python code.  In general, deletes the whitespace before
point, inserts a newline, and takes an educated guess as to how you want
the new line indented."
  (interactive)
  (let ( (ci (current-indentation)) )
    (if (< ci (current-column))		; if point beyond indentation
	(newline-and-indent)
      ;; else try to act like newline-and-indent "normally" acts
      (beginning-of-line)
      (insert-char ?\n 1)
      (move-to-column ci))))

(defun py-compute-indentation ()
  (save-excursion
    (beginning-of-line)
    (cond
     ;; are we on a continuation line?
     ( (py-continuation-line-p)
       (let ( (startpos (point))
	      (open-bracket-pos (py-nesting-level))
	      endpos searching found)
	 (if open-bracket-pos
	     (progn
	       ;; align with first item in list; else a normal
	       ;; indent beyond the line with the open bracket
	       (goto-char (1+ open-bracket-pos)) ; just beyond bracket
	       ;; is the first list item on the same line?
	       (skip-chars-forward " \t")
	       (if (null (memq (following-char) '(?\n ?# ?\\)))
		   ; yes, so line up with it
		   (current-column)
		 ;; first list item on another line, or doesn't exist yet
		 (forward-line 1)
		 (while (and (< (point) startpos)
			     (looking-at "[ \t]*[#\n\\\\]")) ; skip noise
		   (forward-line 1))
		 (if (< (point) startpos)
		     ;; again mimic the first list item
		     (current-indentation)
		   ;; else they're about to enter the first item
		   (goto-char open-bracket-pos)
		   (+ (current-indentation) py-indent-offset))))

	   ;; else on backslash continuation line
	   (forward-line -1)
	   (if (py-continuation-line-p)	; on at least 3rd line in block
	       (current-indentation)	; so just continue the pattern
	     ;; else started on 2nd line in block, so indent more.
	     ;; if base line is an assignment with a start on a RHS,
	     ;; indent to 2 beyond the leftmost "="; else skip first
	     ;; chunk of non-whitespace characters on base line, + 1 more
	     ;; column
	     (end-of-line)
	     (setq endpos (point)  searching t)
	     (back-to-indentation)
	     (setq startpos (point))
	     ;; look at all "=" from left to right, stopping at first
	     ;; one not nested in a list or string
	     (while searching
	       (skip-chars-forward "^=" endpos)
	       (if (= (point) endpos)
		   (setq searching nil)
		 (forward-char 1)
		 (setq state (parse-partial-sexp startpos (point)))
		 (if (and (zerop (car state)) ; not in a bracket
			  (null (nth 3 state)))	; & not in a string
		     (progn
		       (setq searching nil) ; done searching in any case
		       (setq found
			     (not (or
				   (eq (following-char) ?=)
				   (memq (char-after (- (point) 2))
					 '(?< ?> ?!)))))))))
	     (if (or (not found)	; not an assignment
		     (looking-at "[ \t]*\\\\"))	; <=><spaces><backslash>
		 (progn
		   (goto-char startpos)
		   (skip-chars-forward "^ \t\n")))
	     (1+ (current-column))))))

     ;; not on a continuation line

     ;; if at start of restriction, or on a non-indenting comment line,
     ;; assume they intended whatever's there
     ( (or (bobp) (looking-at "[ \t]*#[^ \t\n]"))
       (current-indentation) )

     ;; else indentation based on that of the statement that precedes
     ;; us; use the first line of that statement to establish the base,
     ;; in case the user forced a non-std indentation for the
     ;; continuation lines (if any)
     ( t
       ;; skip back over blank & non-indenting comment lines
       ;; note:  will skip a blank or non-indenting comment line that
       ;; happens to be a continuation line too
       (re-search-backward "^[ \t]*\\([^ \t\n#]\\|#[ \t\n]\\)"
			   nil 'move)
       ;; if we landed inside a string, go to the beginning of that string
       (let ((state (parse-partial-sexp
		     (save-excursion (beginning-of-python-def-or-class)
				     (point))
		     (point))))
	 (if (nth 3 state)
	     (goto-char (nth 2 state))))
       (py-goto-initial-line)
       (if (py-statement-opens-block-p)
	   (+ (current-indentation) py-indent-offset)
	 (current-indentation))))))

(defun py-guess-indent-offset (&optional global)
  "Guess a good value for, and change, py-indent-offset.
By default (without a prefix arg), makes a buffer-local copy of
py-indent-offset with the new value.  This will not affect any other
Python buffers.  With a prefix arg, changes the global value of
py-indent-offset.  This affects all Python buffers (that don't have
their own buffer-local copy), both those currently existing and those
created later in the Emacs session.

Some people use a different value for py-indent-offset than you use.
There's no excuse for such foolishness, but sometimes you have to deal
with their ugly code anyway.  This function examines the file and sets
py-indent-offset to what it thinks it was when they created the mess.

Specifically, it searches forward from the statement containing point,
looking for a line that opens a block of code.  py-indent-offset is set
to the difference in indentation between that line and the Python
statement following it.  If the search doesn't succeed going forward,
it's tried again going backward."
  (interactive "P")			; raw prefix arg
  (let ( new-value
	 (start (point))
	 restart
	 (found nil)
	 colon-indent)
    (py-goto-initial-line)
    (while (not (or found (eobp)))
      (if (re-search-forward ":[ \t]*\\($\\|[#\\]\\)" nil 'move)
	  (progn
	    (setq restart (point))
	    (py-goto-initial-line)
	    (if (py-statement-opens-block-p)
		(setq found t)
	      (goto-char restart)))))
    (if found
	()
      (goto-char start)
      (py-goto-initial-line)
      (while (not (or found (bobp)))
	(setq found
	      (and
	       (re-search-backward ":[ \t]*\\($\\|[#\\]\\)" nil 'move)
	       (or (py-goto-initial-line) t) ; always true -- side effect
	       (py-statement-opens-block-p)))))
    (setq colon-indent (current-indentation)
	  found (and found (zerop (py-next-statement 1)))
	  new-value (- (current-indentation) colon-indent))
    (goto-char start)
    (if found
	(progn
	  (funcall (if global 'kill-local-variable 'make-local-variable)
		   'py-indent-offset)
	  (setq py-indent-offset new-value)
	  (message "%s value of py-indent-offset set to %d"
		   (if global "Global" "Local")
		   py-indent-offset))
      (error "Sorry, couldn't guess a value for py-indent-offset"))))

(defun py-shift-region (start end count)
  (save-excursion
    (goto-char end)   (beginning-of-line) (setq end (point))
    (goto-char start) (beginning-of-line) (setq start (point))
    (indent-rigidly start end count)))

(defun py-shift-region-left (start end &optional count)
  "Shift region of Python code to the left.
The lines from the line containing the start of the current region up
to (but not including) the line containing the end of the region are
shifted to the left, by py-indent-offset columns.

If a prefix argument is given, the region is instead shifted by that
many columns."
  (interactive "*r\nP")   ; region; raw prefix arg
  (py-shift-region start end
		   (- (prefix-numeric-value
		       (or count py-indent-offset)))))

(defun py-shift-region-right (start end &optional count)
  "Shift region of Python code to the right.
The lines from the line containing the start of the current region up
to (but not including) the line containing the end of the region are
shifted to the right, by py-indent-offset columns.

If a prefix argument is given, the region is instead shifted by that
many columns."
  (interactive "*r\nP")   ; region; raw prefix arg
  (py-shift-region start end (prefix-numeric-value
			      (or count py-indent-offset))))

(defun py-indent-region (start end &optional indent-offset)
  "Reindent a region of Python code.
The lines from the line containing the start of the current region up
to (but not including) the line containing the end of the region are
reindented.  If the first line of the region has a non-whitespace
character in the first column, the first line is left alone and the rest
of the region is reindented with respect to it.  Else the entire region
is reindented with respect to the (closest code or indenting-comment)
statement immediately preceding the region.

This is useful when code blocks are moved or yanked, when enclosing
control structures are introduced or removed, or to reformat code using
a new value for the indentation offset.

If a numeric prefix argument is given, it will be used as the value of
the indentation offset.  Else the value of py-indent-offset will be
used.

Warning:  The region must be consistently indented before this function
is called!  This function does not compute proper indentation from
scratch (that's impossible in Python), it merely adjusts the existing
indentation to be correct in context.

Warning:  This function really has no idea what to do with non-indenting
comment lines, and shifts them as if they were indenting comment lines.
Fixing this appears to require telepathy.

Special cases:  whitespace is deleted from blank lines; continuation
lines are shifted by the same amount their initial line was shifted, in
order to preserve their relative indentation with respect to their
initial line; and comment lines beginning in column 1 are ignored."

  (interactive "*r\nP") ; region; raw prefix arg
  (save-excursion
    (goto-char end)   (beginning-of-line) (setq end (point-marker))
    (goto-char start) (beginning-of-line)
    (let ( (py-indent-offset (prefix-numeric-value
			      (or indent-offset py-indent-offset)))
	   (indents '(-1))	; stack of active indent levels
	   (target-column 0)	; column to which to indent
	   (base-shifted-by 0)	; amount last base line was shifted
	   (indent-base (if (looking-at "[ \t\n]")
			    (py-compute-indentation)
			  0))
	   ci)
      (while (< (point) end)
	(setq ci (current-indentation))
	;; figure out appropriate target column
	(cond
	 ( (or (eq (following-char) ?#)	; comment in column 1
	       (looking-at "[ \t]*$"))	; entirely blank
	   (setq target-column 0))
	 ( (py-continuation-line-p)	; shift relative to base line
	   (setq target-column (+ ci base-shifted-by)))
	 (t				; new base line
	  (if (> ci (car indents))	; going deeper; push it
	      (setq indents (cons ci indents))
	    ;; else we should have seen this indent before
	    (setq indents (memq ci indents)) ; pop deeper indents
	    (if (null indents)
		(error "Bad indentation in region, at line %d"
		       (save-restriction
			 (widen)
			 (1+ (count-lines 1 (point)))))))
	  (setq target-column (+ indent-base
				 (* py-indent-offset
				    (- (length indents) 2))))
	  (setq base-shifted-by (- target-column ci))))
	;; shift as needed
	(if (/= ci target-column)
	    (progn
	      (delete-horizontal-space)
	      (indent-to target-column)))
	(forward-line 1))))
  (set-marker end nil))

;;; Functions for moving point

(defun py-previous-statement (count)
  "Go to the start of previous Python statement.
If the statement at point is the i'th Python statement, goes to the
start of statement i-COUNT.  If there is no such statement, goes to the
first statement.  Returns count of statements left to move.
`Statements' do not include blank, comment, or continuation lines."
  (interactive "p") ; numeric prefix arg
  (if (< count 0) (py-next-statement (- count))
    (py-goto-initial-line)
    (let ( start )
      (while (and
	      (setq start (point)) ; always true -- side effect
	      (> count 0)
	      (zerop (forward-line -1))
	      (py-goto-statement-at-or-above))
	(setq count (1- count)))
      (if (> count 0) (goto-char start)))
    count))

(defun py-next-statement (count)
  "Go to the start of next Python statement.
If the statement at point is the i'th Python statement, goes to the
start of statement i+COUNT.  If there is no such statement, goes to the
last statement.  Returns count of statements left to move.  `Statements'
do not include blank, comment, or continuation lines."
  (interactive "p") ; numeric prefix arg
  (if (< count 0) (py-previous-statement (- count))
    (beginning-of-line)
    (let ( start )
      (while (and
	      (setq start (point)) ; always true -- side effect
	      (> count 0)
	      (py-goto-statement-below))
	(setq count (1- count)))
      (if (> count 0) (goto-char start)))
    count))

(defun py-goto-block-up (&optional nomark)
  "Move up to start of current block.
Go to the statement that starts the smallest enclosing block; roughly
speaking, this will be the closest preceding statement that ends with a
colon and is indented less than the statement you started on.  If
successful, also sets the mark to the starting point.

`\\[py-mark-block]' can be used afterward to mark the whole code block, if desired.

If called from a program, the mark will not be set if optional argument
NOMARK is not nil."
  (interactive)
  (let ( (start (point))
	 (found nil)
	 initial-indent)
    (py-goto-initial-line)
    ;; if on blank or non-indenting comment line, use the preceding stmt
    (if (looking-at "[ \t]*\\($\\|#[^ \t\n]\\)")
	(progn
	  (py-goto-statement-at-or-above)
	  (setq found (py-statement-opens-block-p))))
    ;; search back for colon line indented less
    (setq initial-indent (current-indentation))
    (if (zerop initial-indent)
	;; force fast exit
	(goto-char (point-min)))
    (while (not (or found (bobp)))
      (setq found
	    (and
	     (re-search-backward ":[ \t]*\\($\\|[#\\]\\)" nil 'move)
	     (or (py-goto-initial-line) t) ; always true -- side effect
	     (< (current-indentation) initial-indent)
	     (py-statement-opens-block-p))))
    (if found
	(progn
	  (or nomark (push-mark start))
	  (back-to-indentation))
      (goto-char start)
      (error "Enclosing block not found"))))

(defun beginning-of-python-def-or-class (&optional class)
  "Move point to start of def (or class, with prefix arg).

Searches back for the closest preceding `def'.  If you supply a prefix
arg, looks for a `class' instead.  The docs assume the `def' case; just
substitute `class' for `def' for the other case.

If point is in a def statement already, and after the `d', simply moves
point to the start of the statement.

Else (point is not in a def statement, or at or before the `d' of a def
statement), searches for the closest preceding def statement, and leaves
point at its start.  If no such statement can be found, leaves point at
the start of the buffer.

Returns t iff a def statement is found by these rules.

Note that doing this command repeatedly will take you closer to the start
of the buffer each time.

If you want to mark the current def/class, see `\\[mark-python-def-or-class]'."
  (interactive "P")			; raw prefix arg
  (let ( (at-or-before-p (<= (current-column) (current-indentation)))
	 (start-of-line (progn (beginning-of-line) (point)))
	 (start-of-stmt (progn (py-goto-initial-line) (point))))
    (if (or (/= start-of-stmt start-of-line)
	    (not at-or-before-p))
	(end-of-line))			; OK to match on this line
    (re-search-backward (if class "^[ \t]*class\\>" "^[ \t]*def\\>")
	nil 'move)))

(defun end-of-python-def-or-class (&optional class)
  "Move point beyond end of def (or class, with prefix arg) body.

By default, looks for an appropriate `def'.  If you supply a prefix arg,
looks for a `class' instead.  The docs assume the `def' case; just
substitute `class' for `def' for the other case.

If point is in a def statement already, this is the def we use.

Else if the def found by `\\[beginning-of-python-def-or-class]' contains the statement you
started on, that's the def we use.

Else we search forward for the closest following def, and use that.

If a def can be found by these rules, point is moved to the start of the
line immediately following the def block, and the position of the start
of the def is returned.

Else point is moved to the end of the buffer, and nil is returned.

Note that doing this command repeatedly will take you closer to the end
of the buffer each time.

If you want to mark the current def/class, see `\\[mark-python-def-or-class]'."
  (interactive "P")			; raw prefix arg
  (let ( (start (progn (py-goto-initial-line) (point)))
	 (which (if class "class" "def"))
	 (state 'not-found))
    ;; move point to start of appropriate def/class
    (if (looking-at (concat "[ \t]*" which "\\>")) ; already on one
	(setq state 'at-beginning)
      ;; else see if beginning-of-python-def-or-class hits container
      (if (and (beginning-of-python-def-or-class class)
	       (progn (py-goto-beyond-block)
		      (> (point) start)))
	  (setq state 'at-end)
	;; else search forward
	(goto-char start)
	(if (re-search-forward (concat "^[ \t]*" which "\\>") nil 'move)
	    (progn (setq state 'at-beginning)
		   (beginning-of-line)))))
    (cond
     ((eq state 'at-beginning) (py-goto-beyond-block) t)
     ((eq state 'at-end) t)
     ((eq state 'not-found) nil)
     (t (error "internal error in end-of-python-def-or-class")))))

;;; Functions for marking regions

(defun py-mark-block (&optional extend just-move)
  "Mark following block of lines.  With prefix arg, mark structure.
Easier to use than explain.  It sets the region to an `interesting'
block of succeeding lines.  If point is on a blank line, it goes down to
the next non-blank line.  That will be the start of the region.  The end
of the region depends on the kind of line at the start:

 - If a comment, the region will include all succeeding comment lines up
   to (but not including) the next non-comment line (if any).

 - Else if a prefix arg is given, and the line begins one of these
   structures:
\tif elif else try except finally for while def class
   the region will be set to the body of the structure, including
   following blocks that `belong' to it, but excluding trailing blank
   and comment lines.  E.g., if on a `try' statement, the `try' block
   and all (if any) of the following `except' and `finally' blocks that
   belong to the `try' structure will be in the region.  Ditto for
   if/elif/else, for/else and while/else structures, and (a bit
   degenerate, since they're always one-block structures) def and class
   blocks.

 - Else if no prefix argument is given, and the line begins a Python
   block (see list above), and the block is not a `one-liner' (i.e., the
   statement ends with a colon, not with code), the region will include
   all succeeding lines up to (but not including) the next code
   statement (if any) that's indented no more than the starting line,
   except that trailing blank and comment lines are excluded.  E.g., if
   the starting line begins a multi-statement `def' structure, the
   region will be set to the full function definition, but without any
   trailing `noise' lines.

 - Else the region will include all succeeding lines up to (but not
   including) the next blank line, or code or indenting-comment line
   indented strictly less than the starting line.  Trailing indenting
   comment lines are included in this case, but not trailing blank
   lines.

A msg identifying the location of the mark is displayed in the echo
area; or do `\\[exchange-point-and-mark]' to flip down to the end.

If called from a program, optional argument EXTEND plays the role of the
prefix arg, and if optional argument JUST-MOVE is not nil, just moves to
the end of the block (& does not set mark or display a msg)."

  (interactive "P")			; raw prefix arg
  (py-goto-initial-line)
  ;; skip over blank lines
  (while (and
	  (looking-at "[ \t]*$")	; while blank line
	  (not (eobp)))			; & somewhere to go
    (forward-line 1))
  (if (eobp)
      (error "Hit end of buffer without finding a non-blank stmt"))
  (let ( (initial-pos (point))
	 (initial-indent (current-indentation))
	 last-pos			; position of last stmt in region
	 (followers
	  '( (if elif else) (elif elif else) (else)
	     (try except finally) (except except) (finally)
	     (for else) (while else)
	     (def) (class) ) )
	 first-symbol next-symbol)

    (cond
     ;; if comment line, suck up the following comment lines
     ((looking-at "[ \t]*#")
      (re-search-forward "^[ \t]*[^ \t#]" nil 'move) ; look for non-comment
      (re-search-backward "^[ \t]*#")	; and back to last comment in block
      (setq last-pos (point)))

     ;; else if line is a block line and EXTEND given, suck up
     ;; the whole structure
     ((and extend
	   (setq first-symbol (py-suck-up-first-keyword) )
	   (assq first-symbol followers))
      (while (and
	      (or (py-goto-beyond-block) t) ; side effect
	      (forward-line -1)		; side effect
	      (setq last-pos (point))	; side effect
	      (py-goto-statement-below)
	      (= (current-indentation) initial-indent)
	      (setq next-symbol (py-suck-up-first-keyword))
	      (memq next-symbol (cdr (assq first-symbol followers))))
	(setq first-symbol next-symbol)))

     ;; else if line *opens* a block, search for next stmt indented <=
     ((py-statement-opens-block-p)
      (while (and
	      (setq last-pos (point))	; always true -- side effect
	      (py-goto-statement-below)
	      (> (current-indentation) initial-indent))
	nil))

     ;; else plain code line; stop at next blank line, or stmt or
     ;; indenting comment line indented <
     (t
      (while (and
	      (setq last-pos (point))	; always true -- side effect
	      (or (py-goto-beyond-final-line) t)
	      (not (looking-at "[ \t]*$")) ; stop at blank line
	      (or
	       (>= (current-indentation) initial-indent)
	       (looking-at "[ \t]*#[^ \t\n]"))) ; ignore non-indenting #
	nil)))

    ;; skip to end of last stmt
    (goto-char last-pos)
    (py-goto-beyond-final-line)

    ;; set mark & display
    (if just-move
	()				; just return
      (push-mark (point) 'no-msg)
      (forward-line -1)
      (message "Mark set after: %s" (py-suck-up-leading-text))
      (goto-char initial-pos))))

(defun mark-python-def-or-class (&optional class)
  "Set region to body of def (or class, with prefix arg) enclosing point.
Pushes the current mark, then point, on the mark ring (all language
modes do this, but although it's handy it's never documented ...).

In most Emacs language modes, this function bears at least a
hallucinogenic resemblance to  `\\[end-of-python-def-or-class]' and `\\[beginning-of-python-def-or-class]'.

And in earlier versions of Python mode, all 3 were tightly connected.
Turned out that was more confusing than useful:  the `goto start' and
`goto end' commands are usually used to search through a file, and people
expect them to act a lot like `search backward' and `search forward'
string-search commands.  But because Python `def' and `class' can nest to
arbitrary levels, finding the smallest def containing point cannot be
done via a simple backward search:  the def containing point may not be
the closest preceding def, or even the closest preceding def that's
indented less.  The fancy algorithm required is appropriate for the usual
uses of this `mark' command, but not for the `goto' variations.

So the def marked by this command may not be the one either of the `goto'
commands find:  If point is on a blank or non-indenting comment line,
moves back to start of the closest preceding code statement or indenting
comment line.  If this is a `def' statement, that's the def we use.  Else
searches for the smallest enclosing `def' block and uses that.  Else
signals an error.

When an enclosing def is found:  The mark is left immediately beyond the
last line of the def block.  Point is left at the start of the def,
except that:  if the def is preceded by a number of comment lines
followed by (at most) one optional blank line, point is left at the start
of the comments; else if the def is preceded by a blank line, point is
left at its start.

The intent is to mark the containing def/class and its associated
documentation, to make moving and duplicating functions and classes
pleasant."
  (interactive "P")			; raw prefix arg
  (let ( (start (point))
	 (which (if class "class" "def")))
    (push-mark start)
    (if (not (py-go-up-tree-to-keyword which))
	(progn (goto-char start)
	       (error "Enclosing %s not found" which))
      ;; else enclosing def/class found
      (setq start (point))
      (py-goto-beyond-block)
      (push-mark (point))
      (goto-char start)
      (if (zerop (forward-line -1))	; if there is a preceding line
	  (progn
	    (if (looking-at "[ \t]*$")	; it's blank
		(setq start (point))	; so reset start point
	      (goto-char start))	; else try again
	    (if (zerop (forward-line -1))
		(if (looking-at "[ \t]*#") ; a comment
		    ;; look back for non-comment line
		    ;; tricky: note that the regexp matches a blank
		    ;; line, cuz \n is in the 2nd character class
		    (and
		     (re-search-backward "^[ \t]*[^ \t#]" nil 'move)
		     (forward-line 1))
		  ;; no comment, so go back
		  (goto-char start))))))))

(defun py-comment-region (start end &optional uncomment-p)
  "Comment out region of code; with prefix arg, uncomment region.
The lines from the line containing the start of the current region up
to (but not including) the line containing the end of the region are
commented out, by inserting the string py-block-comment-prefix at the
start of each line.  With a prefix arg, removes py-block-comment-prefix
from the start of each line instead."
  (interactive "*r\nP")   ; region; raw prefix arg
  (goto-char end)   (beginning-of-line) (setq end (point))
  (goto-char start) (beginning-of-line) (setq start (point))
  (let ( (prefix-len (length py-block-comment-prefix)) )
    (save-excursion
      (save-restriction
	(narrow-to-region start end)
	(while (not (eobp))
	  (if uncomment-p
	      (and (string= py-block-comment-prefix
			    (buffer-substring
			     (point) (+ (point) prefix-len)))
		   (delete-char prefix-len))
	    (insert py-block-comment-prefix))
	  (forward-line 1))))))

;;; Documentation functions

;; dump the long form of the mode blurb; does the usual doc escapes,
;; plus lines of the form ^[vc]:name$ to suck variable & command
;; docs out of the right places, along with the keys they're on &
;; current values
(defun py-dump-help-string (str)
  (with-output-to-temp-buffer "*Help*"
    (let ( (locals (buffer-local-variables))
	   funckind funcname func funcdoc
	   (start 0) mstart end
	   keys )
      (while (string-match "^%\\([vc]\\):\\(.+\\)\n" str start)
	(setq mstart (match-beginning 0)  end (match-end 0)
	      funckind (substring str (match-beginning 1) (match-end 1))
	      funcname (substring str (match-beginning 2) (match-end 2))
	      func (intern funcname))
	(princ (substitute-command-keys (substring str start mstart)))
	(cond
	 ( (equal funckind "c")		; command
	   (setq funcdoc (documentation func)
		 keys (concat
		       "Key(s): "
		       (mapconcat 'key-description
				  (where-is-internal func py-mode-map)
				  ", "))))
	 ( (equal funckind "v")		; variable
	   (setq funcdoc (substitute-command-keys
			  (get func 'variable-documentation))
		 keys (if (assq func locals)
			  (concat
			   "Local/Global values: "
			   (prin1-to-string (symbol-value func))
			   " / "
			   (prin1-to-string (default-value func)))
			(concat
			 "Value: "
			 (prin1-to-string (symbol-value func))))))
	 ( t				; unexpected
	   (error "Error in py-dump-help-string, tag `%s'" funckind)))
	(princ (format "\n-> %s:\t%s\t%s\n\n"
		       (if (equal funckind "c") "Command" "Variable")
		       funcname keys))
	(princ funcdoc)
	(terpri)
	(setq start end))
      (princ (substitute-command-keys (substring str start))))
    (print-help-return-message)))

(defun py-describe-mode ()
  "Dump long form of Python-mode docs."
  (interactive)
  (py-dump-help-string "Major mode for editing Python files.
Knows about Python indentation, tokens, comments and continuation lines.
Paragraphs are separated by blank lines only.

Major sections below begin with the string `@'; specific function and
variable docs begin with `->'.

@EXECUTING PYTHON CODE

\\[py-execute-buffer]\tsends the entire buffer to the Python interpreter
\\[py-execute-region]\tsends the current region
\\[py-shell]\tstarts a Python interpreter window; this will be used by
\tsubsequent \\[py-execute-buffer] or \\[py-execute-region] commands
%c:py-execute-buffer
%c:py-execute-region
%c:py-shell

@VARIABLES

py-indent-offset\tindentation increment
py-block-comment-prefix\tcomment string used by py-comment-region

py-python-command\tshell command to invoke Python interpreter
py-scroll-process-buffer\talways scroll Python process buffer
py-temp-directory\tdirectory used for temp files (if needed)

py-beep-if-tab-change\tring the bell if tab-width is changed
%v:py-indent-offset
%v:py-block-comment-prefix
%v:py-python-command
%v:py-scroll-process-buffer
%v:py-temp-directory
%v:py-beep-if-tab-change

@KINDS OF LINES

Each physical line in the file is either a `continuation line' (the
preceding line ends with a backslash that's not part of a comment, or the
paren/bracket/brace nesting level at the start of the line is non-zero,
or both) or an `initial line' (everything else).

An initial line is in turn a `blank line' (contains nothing except
possibly blanks or tabs), a `comment line' (leftmost non-blank character
is `#'), or a `code line' (everything else).

Comment Lines

Although all comment lines are treated alike by Python, Python mode
recognizes two kinds that act differently with respect to indentation.

An `indenting comment line' is a comment line with a blank, tab or
nothing after the initial `#'.  The indentation commands (see below)
treat these exactly as if they were code lines:  a line following an
indenting comment line will be indented like the comment line.  All
other comment lines (those with a non-whitespace character immediately
following the initial `#') are `non-indenting comment lines', and their
indentation is ignored by the indentation commands.

Indenting comment lines are by far the usual case, and should be used
whenever possible.  Non-indenting comment lines are useful in cases like
these:

\ta = b   # a very wordy single-line comment that ends up being
\t        #... continued onto another line

\tif a == b:
##\t\tprint 'panic!' # old code we've `commented out'
\t\treturn a

Since the `#...' and `##' comment lines have a non-whitespace character
following the initial `#', Python mode ignores them when computing the
proper indentation for the next line.

Continuation Lines and Statements

The Python-mode commands generally work on statements instead of on
individual lines, where a `statement' is a comment or blank line, or a
code line and all of its following continuation lines (if any)
considered as a single logical unit.  The commands in this mode
generally (when it makes sense) automatically move to the start of the
statement containing point, even if point happens to be in the middle of
some continuation line.


@INDENTATION

Primarily for entering new code:
\t\\[indent-for-tab-command]\t indent line appropriately
\t\\[py-newline-and-indent]\t insert newline, then indent
\t\\[py-delete-char]\t reduce indentation, or delete single character

Primarily for reindenting existing code:
\t\\[py-guess-indent-offset]\t guess py-indent-offset from file content; change locally
\t\\[universal-argument] \\[py-guess-indent-offset]\t ditto, but change globally

\t\\[py-indent-region]\t reindent region to match its context
\t\\[py-shift-region-left]\t shift region left by py-indent-offset
\t\\[py-shift-region-right]\t shift region right by py-indent-offset

Unlike most programming languages, Python uses indentation, and only
indentation, to specify block structure.  Hence the indentation supplied
automatically by Python-mode is just an educated guess:  only you know
the block structure you intend, so only you can supply correct
indentation.

The \\[indent-for-tab-command] and \\[py-newline-and-indent] keys try to suggest plausible indentation, based on
the indentation of preceding statements.  E.g., assuming
py-indent-offset is 4, after you enter
\tif a > 0: \\[py-newline-and-indent]
the cursor will be moved to the position of the `_' (_ is not a
character in the file, it's just used here to indicate the location of
the cursor):
\tif a > 0:
\t    _
If you then enter `c = d' \\[py-newline-and-indent], the cursor will move
to
\tif a > 0:
\t    c = d
\t    _
Python-mode cannot know whether that's what you intended, or whether
\tif a > 0:
\t    c = d
\t_
was your intent.  In general, Python-mode either reproduces the
indentation of the (closest code or indenting-comment) preceding
statement, or adds an extra py-indent-offset blanks if the preceding
statement has `:' as its last significant (non-whitespace and non-
comment) character.  If the suggested indentation is too much, use
\\[py-delete-char] to reduce it.

Continuation lines are given extra indentation.  If you don't like the
suggested indentation, change it to something you do like, and Python-
mode will strive to indent later lines of the statement in the same way.

If a line is a continuation line by virtue of being in an unclosed
paren/bracket/brace structure (`list', for short), the suggested
indentation depends on whether the current line contains the first item
in the list.  If it does, it's indented py-indent-offset columns beyond
the indentation of the line containing the open bracket.  If you don't
like that, change it by hand.  The remaining items in the list will mimic
whatever indentation you give to the first item.

If a line is a continuation line because the line preceding it ends with
a backslash, the third and following lines of the statement inherit their
indentation from the line preceding them.  The indentation of the second
line in the statement depends on the form of the first (base) line:  if
the base line is an assignment statement with anything more interesting
than the backslash following the leftmost assigning `=', the second line
is indented two columns beyond that `='.  Else it's indented to two
columns beyond the leftmost solid chunk of non-whitespace characters on
the base line.

Warning:  indent-region should not normally be used!  It calls \\[indent-for-tab-command]
repeatedly, and as explained above, \\[indent-for-tab-command] can't guess the block
structure you intend.
%c:indent-for-tab-command
%c:py-newline-and-indent
%c:py-delete-char


The next function may be handy when editing code you didn't write:
%c:py-guess-indent-offset


The remaining `indent' functions apply to a region of Python code.  They
assume the block structure (equals indentation, in Python) of the region
is correct, and alter the indentation in various ways while preserving
the block structure:
%c:py-indent-region
%c:py-shift-region-left
%c:py-shift-region-right

@MARKING & MANIPULATING REGIONS OF CODE

\\[py-mark-block]\t mark block of lines
\\[mark-python-def-or-class]\t mark smallest enclosing def
\\[universal-argument] \\[mark-python-def-or-class]\t mark smallest enclosing class
\\[py-comment-region]\t comment out region of code
\\[universal-argument] \\[py-comment-region]\t uncomment region of code
%c:py-mark-block
%c:mark-python-def-or-class
%c:py-comment-region

@MOVING POINT

\\[py-previous-statement]\t move to statement preceding point
\\[py-next-statement]\t move to statement following point
\\[py-goto-block-up]\t move up to start of current block
\\[beginning-of-python-def-or-class]\t move to start of def
\\[universal-argument] \\[beginning-of-python-def-or-class]\t move to start of class
\\[end-of-python-def-or-class]\t move to end of def
\\[universal-argument] \\[end-of-python-def-or-class]\t move to end of class

The first two move to one statement beyond the statement that contains
point.  A numeric prefix argument tells them to move that many
statements instead.  Blank lines, comment lines, and continuation lines
do not count as `statements' for these commands.  So, e.g., you can go
to the first code statement in a file by entering
\t\\[beginning-of-buffer]\t to move to the top of the file
\t\\[py-next-statement]\t to skip over initial comments and blank lines
Or do `\\[py-previous-statement]' with a huge prefix argument.
%c:py-previous-statement
%c:py-next-statement
%c:py-goto-block-up
%c:beginning-of-python-def-or-class
%c:end-of-python-def-or-class

@LITTLE-KNOWN EMACS COMMANDS PARTICULARLY USEFUL IN PYTHON MODE

`\\[indent-new-comment-line]' is handy for entering a multi-line comment.

`\\[set-selective-display]' with a `small' prefix arg is ideally suited for viewing the
overall class and def structure of a module.

`\\[back-to-indentation]' moves point to a line's first non-blank character.

`\\[indent-relative]' is handy for creating odd indentation.

@OTHER EMACS HINTS

If you don't like the default value of a variable, change its value to
whatever you do like by putting a `setq' line in your .emacs file.
E.g., to set the indentation increment to 4, put this line in your
.emacs:
\t(setq  py-indent-offset  4)
To see the value of a variable, do `\\[describe-variable]' and enter the variable
name at the prompt.

When entering a key sequence like `C-c C-n', it is not necessary to
release the CONTROL key after doing the `C-c' part -- it suffices to
press the CONTROL key, press and release `c' (while still holding down
CONTROL), press and release `n' (while still holding down CONTROL), &
then release CONTROL.

Entering Python mode calls with no arguments the value of the variable
`python-mode-hook', if that value exists and is not nil; for backward
compatibility it also tries `py-mode-hook'; see the `Hooks' section of
the Elisp manual for details.

Obscure:  When python-mode is first loaded, it looks for all bindings
to newline-and-indent in the global keymap, and shadows them with
local bindings to py-newline-and-indent."))

;;; Helper functions

(defvar py-parse-state-re
  (concat
   "^[ \t]*\\(if\\|elif\\|else\\|while\\|def\\|class\\)\\>"
   "\\|"
   "^[^ #\t\n]"))
;; returns the parse state at point (see parse-partial-sexp docs)
(defun py-parse-state ()
  (save-excursion
    (let ( (here (point)) )
      ;; back up to the first preceding line (if any; else start of
      ;; buffer) that begins with a popular Python keyword, or a non-
      ;; whitespace and non-comment character.  These are good places to
      ;; start parsing to see whether where we started is at a non-zero
      ;; nesting level.  It may be slow for people who write huge code
      ;; blocks or huge lists ... tough beans.
      (re-search-backward py-parse-state-re nil 'move)
      (beginning-of-line)
      (parse-partial-sexp (point) here))))

;; if point is at a non-zero nesting level, returns the number of the
;; character that opens the smallest enclosing unclosed list; else
;; returns nil.
(defun py-nesting-level ()
  (let ( (status (py-parse-state)) )
    (if (zerop (car status))
	nil				; not in a nest
      (car (cdr status)))))		; char# of open bracket

;; t iff preceding line ends with backslash that's not in a comment
(defun py-backslash-continuation-line-p ()
  (save-excursion
    (beginning-of-line)
    (and
     ;; use a cheap test first to avoid the regexp if possible
     ;; use 'eq' because char-after may return nil
     (eq (char-after (- (point) 2)) ?\\ )
     ;; make sure; since eq test passed, there is a preceding line
     (forward-line -1) ; always true -- side effect
     (looking-at py-continued-re))))

;; t iff current line is a continuation line
(defun py-continuation-line-p ()
  (save-excursion
   (beginning-of-line)
    (or (py-backslash-continuation-line-p)
	(py-nesting-level))))

;; go to initial line of current statement; usually this is the
;; line we're on, but if we're on the 2nd or following lines of a
;; continuation block, we need to go up to the first line of the block.
;;
;; Tricky:  We want to avoid quadratic-time behavior for long continued
;; blocks, whether of the backslash or open-bracket varieties, or a mix
;; of the two.  The following manages to do that in the usual cases.
(defun py-goto-initial-line ()
  (let ( open-bracket-pos )
    (while (py-continuation-line-p)
      (beginning-of-line)
      (if (py-backslash-continuation-line-p)
	  (while (py-backslash-continuation-line-p)
	    (forward-line -1))
	;; else zip out of nested brackets/braces/parens
	(while (setq open-bracket-pos (py-nesting-level))
	  (goto-char open-bracket-pos)))))
  (beginning-of-line))

;; go to point right beyond final line of current statement; usually
;; this is the start of the next line, but if this is a multi-line
;; statement we need to skip over the continuation lines.
;; Tricky:  Again we need to be clever to avoid quadratic time behavior.
(defun py-goto-beyond-final-line ()
  (forward-line 1)
  (let ( state )
    (while (and (py-continuation-line-p)
		(not (eobp)))
      ;; skip over the backslash flavor
      (while (and (py-backslash-continuation-line-p)
		  (not (eobp)))
	(forward-line 1))
      ;; if in nest, zip to the end of the nest
      (setq state (py-parse-state))
      (if (and (not (zerop (car state)))
	       (not (eobp)))
	  (progn
	    ;; BUG ALERT:  I could swear, from reading the docs, that
	    ;; the 3rd argument should be plain 0
	    (parse-partial-sexp (point) (point-max) (- 0 (car state))
				nil state)
	    (forward-line 1))))))

;; t iff statement opens a block == iff it ends with a colon that's
;; not in a comment
;; point should be at the start of a statement
(defun py-statement-opens-block-p ()
  (save-excursion
    (let ( (start (point))
	   (finish (progn (py-goto-beyond-final-line) (1- (point))))
	   (searching t)
	   (answer nil)
	   state)
      (goto-char start)
      (while searching
	;; look for a colon with nothing after it except whitespace, and
	;; maybe a comment
	(if (re-search-forward ":\\([ \t]\\|\\\\\n\\)*\\(#.*\\)?$"
			       finish t)
	    (if (eq (point) finish)	; note: no `else' clause; just
					; keep searching if we're not at
					; the end yet
		;; sure looks like it opens a block -- but it might
		;; be in a comment
		(progn
		  (setq searching nil)	; search is done either way
		  (setq state (parse-partial-sexp start
						  (match-beginning 0)))
		  (setq answer (not (nth 4 state)))))
	  ;; search failed: couldn't find another interesting colon
	  (setq searching nil)))
      answer)))

;; go to point right beyond final line of block begun by the current
;; line.  This is the same as where py-goto-beyond-final-line goes
;; unless we're on colon line, in which case we go to the end of the
;; block.
;; assumes point is at bolp
(defun py-goto-beyond-block ()
  (if (py-statement-opens-block-p)
      (py-mark-block nil 'just-move)
    (py-goto-beyond-final-line)))

;; go to start of first statement (not blank or comment or continuation
;; line) at or preceding point
;; returns t if there is one, else nil
(defun py-goto-statement-at-or-above ()
  (py-goto-initial-line)
  (if (looking-at py-blank-or-comment-re)
	;; skip back over blank & comment lines
	;; note:  will skip a blank or comment line that happens to be
	;; a continuation line too
	(if (re-search-backward "^[ \t]*[^ \t#\n]" nil t)
	    (progn (py-goto-initial-line) t)
	  nil)
    t))

;; go to start of first statement (not blank or comment or continuation
;; line) following the statement containing point
;; returns t if there is one, else nil
(defun py-goto-statement-below ()
  (beginning-of-line)
  (let ( (start (point)) )
    (py-goto-beyond-final-line)
    (while (and
	    (looking-at py-blank-or-comment-re)
	    (not (eobp)))
      (forward-line 1))
    (if (eobp)
	(progn (goto-char start) nil)
      t)))

;; go to start of statement, at or preceding point, starting with keyword
;; KEY.  Skips blank lines and non-indenting comments upward first.  If
;; that statement starts with KEY, done, else go back to first enclosing
;; block starting with KEY.
;; If successful, leaves point at the start of the KEY line & returns t.
;; Else leaves point at an undefined place & returns nil.
(defun py-go-up-tree-to-keyword (key)
  ;; skip blanks and non-indenting #
  (py-goto-initial-line)
  (while (and
	  (looking-at "[ \t]*\\($\\|#[^ \t\n]\\)")
	  (zerop (forward-line -1)))	; go back
    nil)
  (py-goto-initial-line)
  (let* ( (re (concat "[ \t]*" key "\\b"))
	  (case-fold-search nil)	; let* so looking-at sees this
	  (found (looking-at re))
	  (dead nil))
    (while (not (or found dead))
      (condition-case nil		; in case no enclosing block
	  (py-goto-block-up 'no-mark)
	(error (setq dead t)))
      (or dead (setq found (looking-at re))))
    (beginning-of-line)
    found))

;; return string in buffer from start of indentation to end of line;
;; prefix "..." if leading whitespace was skipped
(defun py-suck-up-leading-text ()
  (save-excursion
    (back-to-indentation)
    (concat
     (if (bolp) "" "...")
     (buffer-substring (point) (progn (end-of-line) (point))))))

;; assuming point at bolp, return first keyword ([a-z]+) on the line,
;; as a Lisp symbol; return nil if none
(defun py-suck-up-first-keyword ()
  (let ( (case-fold-search nil) )
    (if (looking-at "[ \t]*\\([a-z]+\\)\\b")
	(intern (buffer-substring (match-beginning 1) (match-end 1)))
      nil)))

(defun py-make-temp-name ()
  (make-temp-name
   (concat (file-name-as-directory py-temp-directory) "python")))

(defun py-delete-file-silently (fname)
  (condition-case nil
      (delete-file fname)
    (error nil)))

(defun py-kill-emacs-hook ()
  ;; delete our temp files
  (while py-file-queue
    (py-delete-file-silently (car py-file-queue))
    (setq py-file-queue (cdr py-file-queue)))
  (if (not (or py-this-is-lucid-emacs-p py-this-is-emacs-19-p))
      ;; run the hook we inherited, if any
      (and py-inherited-kill-emacs-hook
	   (funcall py-inherited-kill-emacs-hook))))

;; make PROCESS's buffer visible, append STRING to it, and force display;
;; also make shell-mode believe the user typed this string, so that
;; kill-output-from-shell and show-output-from-shell work "right"
(defun py-append-to-process-buffer (process string)
  (let ( (cbuf (current-buffer))
	 (pbuf (process-buffer process))
	 (py-scroll-process-buffer t))
    (set-buffer pbuf)
    (goto-char (point-max))
    (move-marker (process-mark process) (point))
    (if (not py-this-is-emacs-19-p)
	(move-marker last-input-start (point))) ; muck w/ shell-mode
    (funcall (process-filter process) process string)
    (if (not py-this-is-emacs-19-p)
	(move-marker last-input-end (point))) ; muck w/ shell-mode
    (set-buffer cbuf))
  (sit-for 0))

;; To do:
;; - support for ptags