File size: 60,948 Bytes
170ebc5
 
 
 
 
 
 
 
781c6a0
170ebc5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "CjRWziAVU2lZ"
      },
      "source": [
        "# Code your first Deep Reinforcement Learning Algorithm with PyTorch: Reinforce. And test its robustness ๐Ÿ’ช\n",
        "\n",
        "<img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit6/thumbnail.png\" alt=\"thumbnail\"/>\n",
        "\n",
        "\n",
        "In this notebook, you'll code your first Deep Reinforcement Learning algorithm from scratch: Reinforce (also called Monte Carlo Policy Gradient).\n",
        "\n",
        "Reinforce is a *Policy-based method*: a Deep Reinforcement Learning algorithm that tries **to optimize the policy directly without using an action-value function**.\n",
        "\n",
        "More precisely, Reinforce is a *Policy-gradient method*, a subclass of *Policy-based methods* that aims **to optimize the policy directly by estimating the weights of the optimal policy using gradient ascent**.\n",
        "\n",
        "To test its robustness, we're going to train it in 2 different simple environments:\n",
        "- Cartpole-v1\n",
        "- PixelcopterEnv\n",
        "\n",
        "โฌ‡๏ธ Here is an example of what **you will achieve at the end of this notebook.** โฌ‡๏ธ"
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "  <img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit6/envs.gif\" alt=\"Environments\"/>\n"
      ],
      "metadata": {
        "id": "s4rBom2sbo7S"
      }
    },
    {
      "cell_type": "markdown",
      "source": [
        "### ๐ŸŽฎ Environments:\n",
        "\n",
        "- [CartPole-v1](https://www.gymlibrary.dev/environments/classic_control/cart_pole/)\n",
        "- [PixelCopter](https://pygame-learning-environment.readthedocs.io/en/latest/user/games/pixelcopter.html)\n",
        "\n",
        "### ๐Ÿ“š RL-Library:\n",
        "\n",
        "- Python\n",
        "- PyTorch\n",
        "\n",
        "\n",
        "We're constantly trying to improve our tutorials, so **if you find some issues in this notebook**, please [open an issue on the GitHub Repo](https://github.com/huggingface/deep-rl-class/issues)."
      ],
      "metadata": {
        "id": "BPLwsPajb1f8"
      }
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "L_WSo0VUV99t"
      },
      "source": [
        "## Objectives of this notebook ๐Ÿ†\n",
        "At the end of the notebook, you will:\n",
        "- Be able to **code from scratch a Reinforce algorithm using PyTorch.**\n",
        "- Be able to **test the robustness of your agent using simple environments.**\n",
        "- Be able to **push your trained agent to the Hub** with a nice video replay and an evaluation score ๐Ÿ”ฅ."
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "lEPrZg2eWa4R"
      },
      "source": [
        "## This notebook is from the Deep Reinforcement Learning Course\n",
        "<img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/notebooks/deep-rl-course-illustration.jpg\" alt=\"Deep RL Course illustration\"/>"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "6p5HnEefISCB"
      },
      "source": [
        "In this free course, you will:\n",
        "\n",
        "- ๐Ÿ“– Study Deep Reinforcement Learning in **theory and practice**.\n",
        "- ๐Ÿง‘โ€๐Ÿ’ป Learn to **use famous Deep RL libraries** such as Stable Baselines3, RL Baselines3 Zoo, CleanRL and Sample Factory 2.0.\n",
        "- ๐Ÿค– Train **agents in unique environments**\n",
        "\n",
        "And more check ๐Ÿ“š the syllabus ๐Ÿ‘‰ https://simoninithomas.github.io/deep-rl-course\n",
        "\n",
        "Donโ€™t forget to **<a href=\"http://eepurl.com/ic5ZUD\">sign up to the course</a>** (we are collecting your email to be able toย **send you the links when each Unit is published and give you information about the challenges and updates).**\n",
        "\n",
        "\n",
        "The best way to keep in touch is to join our discord server to exchange with the community and with us ๐Ÿ‘‰๐Ÿป https://discord.gg/ydHrjt3WP5"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "mjY-eq3eWh9O"
      },
      "source": [
        "## Prerequisites ๐Ÿ—๏ธ\n",
        "Before diving into the notebook, you need to:\n",
        "\n",
        "๐Ÿ”ฒ ๐Ÿ“š [Study Policy Gradients by reading Unit 4](https://huggingface.co/deep-rl-course/unit4/introduction)"
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "# Let's code Reinforce algorithm from scratch ๐Ÿ”ฅ\n",
        "\n",
        "\n",
        "To validate this hands-on for the certification process, you need to push your trained models to the Hub.\n",
        "\n",
        "- Get a result of >= 350 for `Cartpole-v1`.\n",
        "- Get a result of >= 5 for `PixelCopter`.\n",
        "\n",
        "To find your result, go to the leaderboard and find your model, **the result = mean_reward - std of reward**. **If you don't see your model on the leaderboard, go at the bottom of the leaderboard page and click on the refresh button**.\n",
        "\n",
        "For more information about the certification process, check this section ๐Ÿ‘‰ https://huggingface.co/deep-rl-course/en/unit0/introduction#certification-process\n"
      ],
      "metadata": {
        "id": "Bsh4ZAamchSl"
      }
    },
    {
      "cell_type": "markdown",
      "source": [
        "## An advice ๐Ÿ’ก\n",
        "It's better to run this colab in a copy on your Google Drive, so that **if it timeouts** you still have the saved notebook on your Google Drive and do not need to fill everything from scratch.\n",
        "\n",
        "To do that you can either do `Ctrl + S` or `File > Save a copy in Google Drive.`"
      ],
      "metadata": {
        "id": "JoTC9o2SczNn"
      }
    },
    {
      "cell_type": "markdown",
      "source": [
        "## Set the GPU ๐Ÿ’ช\n",
        "- To **accelerate the agent's training, we'll use a GPU**. To do that, go to `Runtime > Change Runtime type`\n",
        "\n",
        "<img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/notebooks/gpu-step1.jpg\" alt=\"GPU Step 1\">"
      ],
      "metadata": {
        "id": "PU4FVzaoM6fC"
      }
    },
    {
      "cell_type": "markdown",
      "source": [
        "- `Hardware Accelerator > GPU`\n",
        "\n",
        "<img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/notebooks/gpu-step2.jpg\" alt=\"GPU Step 2\">"
      ],
      "metadata": {
        "id": "KV0NyFdQM9ZG"
      }
    },
    {
      "cell_type": "markdown",
      "source": [
        "## Create a virtual display ๐Ÿ–ฅ\n",
        "\n",
        "During the notebook, we'll need to generate a replay video. To do so, with colab, **we need to have a virtual screen to be able to render the environment** (and thus record the frames).\n",
        "\n",
        "Hence the following cell will install the librairies and create and run a virtual screen ๐Ÿ–ฅ"
      ],
      "metadata": {
        "id": "bTpYcVZVMzUI"
      }
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "jV6wjQ7Be7p5"
      },
      "outputs": [],
      "source": [
        "%%capture\n",
        "!apt install python-opengl\n",
        "!apt install ffmpeg\n",
        "!apt install xvfb\n",
        "!pip install pyvirtualdisplay\n",
        "!pip install pyglet==1.5.1"
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "# Virtual display\n",
        "from pyvirtualdisplay import Display\n",
        "\n",
        "virtual_display = Display(visible=0, size=(1400, 900))\n",
        "virtual_display.start()"
      ],
      "metadata": {
        "id": "Sr-Nuyb1dBm0"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "tjrLfPFIW8XK"
      },
      "source": [
        "## Install the dependencies ๐Ÿ”ฝ\n",
        "The first step is to install the dependencies. Weโ€™ll install multiple ones:\n",
        "\n",
        "- `gym`\n",
        "- `gym-games`: Extra gym environments made with PyGame.\n",
        "- `huggingface_hub`: ๐Ÿค— works as a central place where anyone can share and explore models and datasets. It has versioning, metrics, visualizations, and other features that will allow you to easily collaborate with others.\n",
        "\n",
        "You may be wondering why we install gym and not gymnasium, a more recent version of gym? **Because the gym-games we are using are not updated yet with gymnasium**.\n",
        "\n",
        "The differences you'll encounter here:\n",
        "- In `gym` we don't have `terminated` and `truncated` but only `done`.\n",
        "- In `gym` using `env.step()` returns `state, reward, done, info`\n",
        "\n",
        "You can learn more about the differences between Gym and Gymnasium here ๐Ÿ‘‰ https://gymnasium.farama.org/content/migration-guide/\n",
        "\n",
        "\n",
        "You can see here all the Reinforce models available ๐Ÿ‘‰ https://huggingface.co/models?other=reinforce\n",
        "\n",
        "And you can find all the Deep Reinforcement Learning models here ๐Ÿ‘‰ https://huggingface.co/models?pipeline_tag=reinforcement-learning\n"
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "!pip install -r https://raw.githubusercontent.com/huggingface/deep-rl-class/main/notebooks/unit4/requirements-unit4.txt"
      ],
      "metadata": {
        "id": "e8ZVi-uydpgL"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "AAHAq6RZW3rn"
      },
      "source": [
        "## Import the packages ๐Ÿ“ฆ\n",
        "In addition to import the installed libraries, we also import:\n",
        "\n",
        "- `imageio`: A library that will help us to generate a replay video\n",
        "\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "V8oadoJSWp7C"
      },
      "outputs": [],
      "source": [
        "import numpy as np\n",
        "\n",
        "from collections import deque\n",
        "\n",
        "import matplotlib.pyplot as plt\n",
        "%matplotlib inline\n",
        "\n",
        "# PyTorch\n",
        "import torch\n",
        "import torch.nn as nn\n",
        "import torch.nn.functional as F\n",
        "import torch.optim as optim\n",
        "from torch.distributions import Categorical\n",
        "\n",
        "# Gym\n",
        "import gym\n",
        "import gym_pygame\n",
        "\n",
        "# Hugging Face Hub\n",
        "from huggingface_hub import notebook_login # To log to our Hugging Face account to be able to upload models to the Hub.\n",
        "import imageio"
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "## Check if we have a GPU\n",
        "\n",
        "- Let's check if we have a GPU\n",
        "- If it's the case you should see `device:cuda0`"
      ],
      "metadata": {
        "id": "RfxJYdMeeVgv"
      }
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "kaJu5FeZxXGY"
      },
      "outputs": [],
      "source": [
        "device = torch.device(\"cuda:0\" if torch.cuda.is_available() else \"cpu\")"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "U5TNYa14aRav"
      },
      "outputs": [],
      "source": [
        "print(device)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "PBPecCtBL_pZ"
      },
      "source": [
        "We're now ready to implement our Reinforce algorithm ๐Ÿ”ฅ"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "8KEyKYo2ZSC-"
      },
      "source": [
        "# First agent: Playing CartPole-v1 ๐Ÿค–"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "haLArKURMyuF"
      },
      "source": [
        "## Create the CartPole environment and understand how it works\n",
        "### [The environment ๐ŸŽฎ](https://www.gymlibrary.dev/environments/classic_control/cart_pole/)\n"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "AH_TaLKFXo_8"
      },
      "source": [
        "### Why do we use a simple environment like CartPole-v1?\n",
        "As explained in [Reinforcement Learning Tips and Tricks](https://stable-baselines3.readthedocs.io/en/master/guide/rl_tips.html), when you implement your agent from scratch you need **to be sure that it works correctly and find bugs with easy environments before going deeper**. Since finding bugs will be much easier in simple environments.\n",
        "\n",
        "\n",
        "> Try to have some โ€œsign of lifeโ€ on toy problems\n",
        "\n",
        "\n",
        "> Validate the implementation by making it run on harder and harder envs (you can compare results against the RL zoo). You usually need to run hyperparameter optimization for that step.\n",
        "___\n",
        "### The CartPole-v1 environment\n",
        "\n",
        "> A pole is attached by an un-actuated joint to a cart, which moves along a frictionless track. The pendulum is placed upright on the cart and the goal is to balance the pole by applying forces in the left and right direction on the cart.\n",
        "\n",
        "\n",
        "\n",
        "So, we start with CartPole-v1. The goal is to push the cart left or right **so that the pole stays in the equilibrium.**\n",
        "\n",
        "The episode ends if:\n",
        "- The pole Angle is greater than ยฑ12ยฐ\n",
        "- Cart Position is greater than ยฑ2.4\n",
        "- Episode length is greater than 500\n",
        "\n",
        "We get a reward ๐Ÿ’ฐ of +1 every timestep the Pole stays in the equilibrium."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "POOOk15_K6KA"
      },
      "outputs": [],
      "source": [
        "env_id = \"CartPole-v1\"\n",
        "# Create the env\n",
        "env = gym.make(env_id)\n",
        "\n",
        "# Create the evaluation env\n",
        "eval_env = gym.make(env_id)\n",
        "\n",
        "# Get the state space and action space\n",
        "s_size = env.observation_space.shape[0]\n",
        "a_size = env.action_space.n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "FMLFrjiBNLYJ"
      },
      "outputs": [],
      "source": [
        "print(\"_____OBSERVATION SPACE_____ \\n\")\n",
        "print(\"The State Space is: \", s_size)\n",
        "print(\"Sample observation\", env.observation_space.sample()) # Get a random observation"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "Lu6t4sRNNWkN"
      },
      "outputs": [],
      "source": [
        "print(\"\\n _____ACTION SPACE_____ \\n\")\n",
        "print(\"The Action Space is: \", a_size)\n",
        "print(\"Action Space Sample\", env.action_space.sample()) # Take a random action"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "7SJMJj3WaFOz"
      },
      "source": [
        "## Let's build the Reinforce Architecture\n",
        "This implementation is based on two implementations:\n",
        "- [PyTorch official Reinforcement Learning example](https://github.com/pytorch/examples/blob/main/reinforcement_learning/reinforce.py)\n",
        "- [Udacity Reinforce](https://github.com/udacity/deep-reinforcement-learning/blob/master/reinforce/REINFORCE.ipynb)\n",
        "- [Improvement of the integration by Chris1nexus](https://github.com/huggingface/deep-rl-class/pull/95)\n",
        "\n",
        "<img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit6/reinforce.png\" alt=\"Reinforce\"/>"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "49kogtxBODX8"
      },
      "source": [
        "So we want:\n",
        "- Two fully connected layers (fc1 and fc2).\n",
        "- Using ReLU as activation function of fc1\n",
        "- Using Softmax to output a probability distribution over actions"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "w2LHcHhVZvPZ"
      },
      "outputs": [],
      "source": [
        "class Policy(nn.Module):\n",
        "    def __init__(self, s_size, a_size, h_size):\n",
        "        super(Policy, self).__init__()\n",
        "        # Create two fully connected layers\n",
        "\n",
        "\n",
        "\n",
        "    def forward(self, x):\n",
        "        # Define the forward pass\n",
        "        # state goes to fc1 then we apply ReLU activation function\n",
        "\n",
        "        # fc1 outputs goes to fc2\n",
        "\n",
        "        # We output the softmax\n",
        "\n",
        "    def act(self, state):\n",
        "        \"\"\"\n",
        "        Given a state, take action\n",
        "        \"\"\"\n",
        "        state = torch.from_numpy(state).float().unsqueeze(0).to(device)\n",
        "        probs = self.forward(state).cpu()\n",
        "        m = Categorical(probs)\n",
        "        action = np.argmax(m)\n",
        "        return action.item(), m.log_prob(action)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "rOMrdwSYOWSC"
      },
      "source": [
        "### Solution"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "jGdhRSVrOV4K"
      },
      "outputs": [],
      "source": [
        "class Policy(nn.Module):\n",
        "    def __init__(self, s_size, a_size, h_size):\n",
        "        super(Policy, self).__init__()\n",
        "        self.fc1 = nn.Linear(s_size, h_size)\n",
        "        self.fc2 = nn.Linear(h_size, a_size)\n",
        "\n",
        "    def forward(self, x):\n",
        "        x = F.relu(self.fc1(x))\n",
        "        x = self.fc2(x)\n",
        "        return F.softmax(x, dim=1)\n",
        "\n",
        "    def act(self, state):\n",
        "        state = torch.from_numpy(state).float().unsqueeze(0).to(device)\n",
        "        probs = self.forward(state).cpu()\n",
        "        m = Categorical(probs)\n",
        "        action = np.argmax(m)\n",
        "        return action.item(), m.log_prob(action)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "ZTGWL4g2eM5B"
      },
      "source": [
        "I make a mistake, can you guess where?\n",
        "\n",
        "- To find out let's make a forward pass:"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "lwnqGBCNePor"
      },
      "outputs": [],
      "source": [
        "debug_policy = Policy(s_size, a_size, 64).to(device)\n",
        "debug_policy.act(env.reset())"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "14UYkoxCPaor"
      },
      "source": [
        "- Here we see that the error says `ValueError: The value argument to log_prob must be a Tensor`\n",
        "\n",
        "- It means that `action` in `m.log_prob(action)` must be a Tensor **but it's not.**\n",
        "\n",
        "- Do you know why? Check the act function and try to see why it does not work.\n",
        "\n",
        "Advice ๐Ÿ’ก: Something is wrong in this implementation. Remember that we act function **we want to sample an action from the probability distribution over actions**.\n"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "gfGJNZBUP7Vn"
      },
      "source": [
        "### (Real) Solution"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "Ho_UHf49N9i4"
      },
      "outputs": [],
      "source": [
        "class Policy(nn.Module):\n",
        "    def __init__(self, s_size, a_size, h_size):\n",
        "        super(Policy, self).__init__()\n",
        "        self.fc1 = nn.Linear(s_size, h_size)\n",
        "        self.fc2 = nn.Linear(h_size, a_size)\n",
        "\n",
        "    def forward(self, x):\n",
        "        x = F.relu(self.fc1(x))\n",
        "        x = self.fc2(x)\n",
        "        return F.softmax(x, dim=1)\n",
        "\n",
        "    def act(self, state):\n",
        "        state = torch.from_numpy(state).float().unsqueeze(0).to(device)\n",
        "        probs = self.forward(state).cpu()\n",
        "        m = Categorical(probs)\n",
        "        action = m.sample()\n",
        "        return action.item(), m.log_prob(action)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "rgJWQFU_eUYw"
      },
      "source": [
        "By using CartPole, it was easier to debug since **we know that the bug comes from our integration and not from our simple environment**."
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "- Since **we want to sample an action from the probability distribution over actions**, we can't use `action = np.argmax(m)` since it will always output the action that have the highest probability.\n",
        "\n",
        "- We need to replace with `action = m.sample()` that will sample an action from the probability distribution P(.|s)"
      ],
      "metadata": {
        "id": "c-20i7Pk0l1T"
      }
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "4MXoqetzfIoW"
      },
      "source": [
        "### Let's build the Reinforce Training Algorithm\n",
        "This is the Reinforce algorithm pseudocode:\n",
        "\n",
        "<img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit6/pg_pseudocode.png\" alt=\"Policy gradient pseudocode\"/>\n",
        "  "
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "- When we calculate the return Gt (line 6) we see that we calculate the sum of discounted rewards **starting at timestep t**.\n",
        "\n",
        "- Why? Because our policy should only **reinforce actions on the basis of the consequences**: so rewards obtained before taking an action are useless (since they were not because of the action), **only the ones that come after the action matters**.\n",
        "\n",
        "- Before coding this you should read this section [don't let the past distract you](https://spinningup.openai.com/en/latest/spinningup/rl_intro3.html#don-t-let-the-past-distract-you) that explains why we use reward-to-go policy gradient.\n",
        "\n",
        "We use an interesting technique coded by [Chris1nexus](https://github.com/Chris1nexus) to **compute the return at each timestep efficiently**. The comments explained the procedure. Don't hesitate also [to check the PR explanation](https://github.com/huggingface/deep-rl-class/pull/95)\n",
        "But overall the idea is to **compute the return at each timestep efficiently**."
      ],
      "metadata": {
        "id": "QmcXG-9i2Qu2"
      }
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "O554nUGPpcoq"
      },
      "source": [
        "The second question you may ask is **why do we minimize the loss**? You talked about Gradient Ascent not Gradient Descent?\n",
        "\n",
        "- We want to maximize our utility function $J(\\theta)$ but in PyTorch like in Tensorflow it's better to **minimize an objective function.**\n",
        "    - So let's say we want to reinforce action 3 at a certain timestep. Before training this action P is 0.25.\n",
        "    - So we want to modify $\\theta$ such that $\\pi_\\theta(a_3|s; \\theta) > 0.25$\n",
        "    - Because all P must sum to 1, max $\\pi_\\theta(a_3|s; \\theta)$ will **minimize other action probability.**\n",
        "    - So we should tell PyTorch **to min $1 - \\pi_\\theta(a_3|s; \\theta)$.**\n",
        "    - This loss function approaches 0 as $\\pi_\\theta(a_3|s; \\theta)$ nears 1.\n",
        "    - So we are encouraging the gradient to max $\\pi_\\theta(a_3|s; \\theta)$\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "iOdv8Q9NfLK7"
      },
      "outputs": [],
      "source": [
        "def reinforce(policy, optimizer, n_training_episodes, max_t, gamma, print_every):\n",
        "    # Help us to calculate the score during the training\n",
        "    scores_deque = deque(maxlen=100)\n",
        "    scores = []\n",
        "    # Line 3 of pseudocode\n",
        "    for i_episode in range(1, n_training_episodes+1):\n",
        "        saved_log_probs = []\n",
        "        rewards = []\n",
        "        state = # TODO: reset the environment\n",
        "        # Line 4 of pseudocode\n",
        "        for t in range(max_t):\n",
        "            action, log_prob = # TODO get the action\n",
        "            saved_log_probs.append(log_prob)\n",
        "            state, reward, done, _ = # TODO: take an env step\n",
        "            rewards.append(reward)\n",
        "            if done:\n",
        "                break\n",
        "        scores_deque.append(sum(rewards))\n",
        "        scores.append(sum(rewards))\n",
        "\n",
        "        # Line 6 of pseudocode: calculate the return\n",
        "        returns = deque(maxlen=max_t)\n",
        "        n_steps = len(rewards)\n",
        "        # Compute the discounted returns at each timestep,\n",
        "        # as the sum of the gamma-discounted return at time t (G_t) + the reward at time t\n",
        "\n",
        "        # In O(N) time, where N is the number of time steps\n",
        "        # (this definition of the discounted return G_t follows the definition of this quantity\n",
        "        # shown at page 44 of Sutton&Barto 2017 2nd draft)\n",
        "        # G_t = r_(t+1) + r_(t+2) + ...\n",
        "\n",
        "        # Given this formulation, the returns at each timestep t can be computed\n",
        "        # by re-using the computed future returns G_(t+1) to compute the current return G_t\n",
        "        # G_t = r_(t+1) + gamma*G_(t+1)\n",
        "        # G_(t-1) = r_t + gamma* G_t\n",
        "        # (this follows a dynamic programming approach, with which we memorize solutions in order\n",
        "        # to avoid computing them multiple times)\n",
        "\n",
        "        # This is correct since the above is equivalent to (see also page 46 of Sutton&Barto 2017 2nd draft)\n",
        "        # G_(t-1) = r_t + gamma*r_(t+1) + gamma*gamma*r_(t+2) + ...\n",
        "\n",
        "\n",
        "        ## Given the above, we calculate the returns at timestep t as:\n",
        "        #               gamma[t] * return[t] + reward[t]\n",
        "        #\n",
        "        ## We compute this starting from the last timestep to the first, in order\n",
        "        ## to employ the formula presented above and avoid redundant computations that would be needed\n",
        "        ## if we were to do it from first to last.\n",
        "\n",
        "        ## Hence, the queue \"returns\" will hold the returns in chronological order, from t=0 to t=n_steps\n",
        "        ## thanks to the appendleft() function which allows to append to the position 0 in constant time O(1)\n",
        "        ## a normal python list would instead require O(N) to do this.\n",
        "        for t in range(n_steps)[::-1]:\n",
        "            disc_return_t = (returns[0] if len(returns)>0 else 0)\n",
        "            returns.appendleft(    ) # TODO: complete here\n",
        "\n",
        "        ## standardization of the returns is employed to make training more stable\n",
        "        eps = np.finfo(np.float32).eps.item()\n",
        "\n",
        "        ## eps is the smallest representable float, which is\n",
        "        # added to the standard deviation of the returns to avoid numerical instabilities\n",
        "        returns = torch.tensor(returns)\n",
        "        returns = (returns - returns.mean()) / (returns.std() + eps)\n",
        "\n",
        "        # Line 7:\n",
        "        policy_loss = []\n",
        "        for log_prob, disc_return in zip(saved_log_probs, returns):\n",
        "            policy_loss.append(-log_prob * disc_return)\n",
        "        policy_loss = torch.cat(policy_loss).sum()\n",
        "\n",
        "        # Line 8: PyTorch prefers gradient descent\n",
        "        optimizer.zero_grad()\n",
        "        policy_loss.backward()\n",
        "        optimizer.step()\n",
        "\n",
        "        if i_episode % print_every == 0:\n",
        "            print('Episode {}\\tAverage Score: {:.2f}'.format(i_episode, np.mean(scores_deque)))\n",
        "\n",
        "    return scores"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "YB0Cxrw1StrP"
      },
      "source": [
        "#### Solution"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "NCNvyElRStWG"
      },
      "outputs": [],
      "source": [
        "def reinforce(policy, optimizer, n_training_episodes, max_t, gamma, print_every):\n",
        "    # Help us to calculate the score during the training\n",
        "    scores_deque = deque(maxlen=100)\n",
        "    scores = []\n",
        "    # Line 3 of pseudocode\n",
        "    for i_episode in range(1, n_training_episodes+1):\n",
        "        saved_log_probs = []\n",
        "        rewards = []\n",
        "        state = env.reset()\n",
        "        # Line 4 of pseudocode\n",
        "        for t in range(max_t):\n",
        "            action, log_prob = policy.act(state)\n",
        "            saved_log_probs.append(log_prob)\n",
        "            state, reward, done, _ = env.step(action)\n",
        "            rewards.append(reward)\n",
        "            if done:\n",
        "                break\n",
        "        scores_deque.append(sum(rewards))\n",
        "        scores.append(sum(rewards))\n",
        "\n",
        "        # Line 6 of pseudocode: calculate the return\n",
        "        returns = deque(maxlen=max_t)\n",
        "        n_steps = len(rewards)\n",
        "        # Compute the discounted returns at each timestep,\n",
        "        # as\n",
        "        #      the sum of the gamma-discounted return at time t (G_t) + the reward at time t\n",
        "        #\n",
        "        # In O(N) time, where N is the number of time steps\n",
        "        # (this definition of the discounted return G_t follows the definition of this quantity\n",
        "        # shown at page 44 of Sutton&Barto 2017 2nd draft)\n",
        "        # G_t = r_(t+1) + r_(t+2) + ...\n",
        "\n",
        "        # Given this formulation, the returns at each timestep t can be computed\n",
        "        # by re-using the computed future returns G_(t+1) to compute the current return G_t\n",
        "        # G_t = r_(t+1) + gamma*G_(t+1)\n",
        "        # G_(t-1) = r_t + gamma* G_t\n",
        "        # (this follows a dynamic programming approach, with which we memorize solutions in order\n",
        "        # to avoid computing them multiple times)\n",
        "\n",
        "        # This is correct since the above is equivalent to (see also page 46 of Sutton&Barto 2017 2nd draft)\n",
        "        # G_(t-1) = r_t + gamma*r_(t+1) + gamma*gamma*r_(t+2) + ...\n",
        "\n",
        "\n",
        "        ## Given the above, we calculate the returns at timestep t as:\n",
        "        #               gamma[t] * return[t] + reward[t]\n",
        "        #\n",
        "        ## We compute this starting from the last timestep to the first, in order\n",
        "        ## to employ the formula presented above and avoid redundant computations that would be needed\n",
        "        ## if we were to do it from first to last.\n",
        "\n",
        "        ## Hence, the queue \"returns\" will hold the returns in chronological order, from t=0 to t=n_steps\n",
        "        ## thanks to the appendleft() function which allows to append to the position 0 in constant time O(1)\n",
        "        ## a normal python list would instead require O(N) to do this.\n",
        "        for t in range(n_steps)[::-1]:\n",
        "            disc_return_t = (returns[0] if len(returns)>0 else 0)\n",
        "            returns.appendleft( gamma*disc_return_t + rewards[t]   )\n",
        "\n",
        "        ## standardization of the returns is employed to make training more stable\n",
        "        eps = np.finfo(np.float32).eps.item()\n",
        "        ## eps is the smallest representable float, which is\n",
        "        # added to the standard deviation of the returns to avoid numerical instabilities\n",
        "        returns = torch.tensor(returns)\n",
        "        returns = (returns - returns.mean()) / (returns.std() + eps)\n",
        "\n",
        "        # Line 7:\n",
        "        policy_loss = []\n",
        "        for log_prob, disc_return in zip(saved_log_probs, returns):\n",
        "            policy_loss.append(-log_prob * disc_return)\n",
        "        policy_loss = torch.cat(policy_loss).sum()\n",
        "\n",
        "        # Line 8: PyTorch prefers gradient descent\n",
        "        optimizer.zero_grad()\n",
        "        policy_loss.backward()\n",
        "        optimizer.step()\n",
        "\n",
        "        if i_episode % print_every == 0:\n",
        "            print('Episode {}\\tAverage Score: {:.2f}'.format(i_episode, np.mean(scores_deque)))\n",
        "\n",
        "    return scores"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "RIWhQyJjfpEt"
      },
      "source": [
        "##  Train it\n",
        "- We're now ready to train our agent.\n",
        "- But first, we define a variable containing all the training hyperparameters.\n",
        "- You can change the training parameters (and should ๐Ÿ˜‰)"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "utRe1NgtVBYF"
      },
      "outputs": [],
      "source": [
        "cartpole_hyperparameters = {\n",
        "    \"h_size\": 16,\n",
        "    \"n_training_episodes\": 1000,\n",
        "    \"n_evaluation_episodes\": 10,\n",
        "    \"max_t\": 1000,\n",
        "    \"gamma\": 1.0,\n",
        "    \"lr\": 1e-2,\n",
        "    \"env_id\": env_id,\n",
        "    \"state_space\": s_size,\n",
        "    \"action_space\": a_size,\n",
        "}"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "D3lWyVXBVfl6"
      },
      "outputs": [],
      "source": [
        "# Create policy and place it to the device\n",
        "cartpole_policy = Policy(cartpole_hyperparameters[\"state_space\"], cartpole_hyperparameters[\"action_space\"], cartpole_hyperparameters[\"h_size\"]).to(device)\n",
        "cartpole_optimizer = optim.Adam(cartpole_policy.parameters(), lr=cartpole_hyperparameters[\"lr\"])"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "uGf-hQCnfouB"
      },
      "outputs": [],
      "source": [
        "scores = reinforce(cartpole_policy,\n",
        "                   cartpole_optimizer,\n",
        "                   cartpole_hyperparameters[\"n_training_episodes\"],\n",
        "                   cartpole_hyperparameters[\"max_t\"],\n",
        "                   cartpole_hyperparameters[\"gamma\"],\n",
        "                   100)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "Qajj2kXqhB3g"
      },
      "source": [
        "## Define evaluation method ๐Ÿ“\n",
        "- Here we define the evaluation method that we're going to use to test our Reinforce agent."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "3FamHmxyhBEU"
      },
      "outputs": [],
      "source": [
        "def evaluate_agent(env, max_steps, n_eval_episodes, policy):\n",
        "  \"\"\"\n",
        "  Evaluate the agent for ``n_eval_episodes`` episodes and returns average reward and std of reward.\n",
        "  :param env: The evaluation environment\n",
        "  :param n_eval_episodes: Number of episode to evaluate the agent\n",
        "  :param policy: The Reinforce agent\n",
        "  \"\"\"\n",
        "  episode_rewards = []\n",
        "  for episode in range(n_eval_episodes):\n",
        "    state = env.reset()\n",
        "    step = 0\n",
        "    done = False\n",
        "    total_rewards_ep = 0\n",
        "\n",
        "    for step in range(max_steps):\n",
        "      action, _ = policy.act(state)\n",
        "      new_state, reward, done, info = env.step(action)\n",
        "      total_rewards_ep += reward\n",
        "\n",
        "      if done:\n",
        "        break\n",
        "      state = new_state\n",
        "    episode_rewards.append(total_rewards_ep)\n",
        "  mean_reward = np.mean(episode_rewards)\n",
        "  std_reward = np.std(episode_rewards)\n",
        "\n",
        "  return mean_reward, std_reward"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "xdH2QCrLTrlT"
      },
      "source": [
        "## Evaluate our agent ๐Ÿ“ˆ"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "ohGSXDyHh0xx"
      },
      "outputs": [],
      "source": [
        "evaluate_agent(eval_env,\n",
        "               cartpole_hyperparameters[\"max_t\"],\n",
        "               cartpole_hyperparameters[\"n_evaluation_episodes\"],\n",
        "               cartpole_policy)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "7CoeLkQ7TpO8"
      },
      "source": [
        "### Publish our trained model on the Hub ๐Ÿ”ฅ\n",
        "Now that we saw we got good results after the training, we can publish our trained model on the hub ๐Ÿค— with one line of code.\n",
        "\n",
        "Here's an example of a Model Card:\n",
        "\n",
        "<img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit6/modelcard.png\"/>"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "Jmhs1k-cftIq"
      },
      "source": [
        "### Push to the Hub\n",
        "#### Do not modify this code"
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "from huggingface_hub import HfApi, snapshot_download\n",
        "from huggingface_hub.repocard import metadata_eval_result, metadata_save\n",
        "\n",
        "from pathlib import Path\n",
        "import datetime\n",
        "import json\n",
        "import imageio\n",
        "\n",
        "import tempfile\n",
        "\n",
        "import os"
      ],
      "metadata": {
        "id": "LIVsvlW_8tcw"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "Lo4JH45if81z"
      },
      "outputs": [],
      "source": [
        "def record_video(env, policy, out_directory, fps=30):\n",
        "  \"\"\"\n",
        "  Generate a replay video of the agent\n",
        "  :param env\n",
        "  :param Qtable: Qtable of our agent\n",
        "  :param out_directory\n",
        "  :param fps: how many frame per seconds (with taxi-v3 and frozenlake-v1 we use 1)\n",
        "  \"\"\"\n",
        "  images = []\n",
        "  done = False\n",
        "  state = env.reset()\n",
        "  img = env.render(mode='rgb_array')\n",
        "  images.append(img)\n",
        "  while not done:\n",
        "    # Take the action (index) that have the maximum expected future reward given that state\n",
        "    action, _ = policy.act(state)\n",
        "    state, reward, done, info = env.step(action) # We directly put next_state = state for recording logic\n",
        "    img = env.render(mode='rgb_array')\n",
        "    images.append(img)\n",
        "  imageio.mimsave(out_directory, [np.array(img) for i, img in enumerate(images)], fps=fps)"
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "def push_to_hub(repo_id,\n",
        "                model,\n",
        "                hyperparameters,\n",
        "                eval_env,\n",
        "                video_fps=30\n",
        "                ):\n",
        "  \"\"\"\n",
        "  Evaluate, Generate a video and Upload a model to Hugging Face Hub.\n",
        "  This method does the complete pipeline:\n",
        "  - It evaluates the model\n",
        "  - It generates the model card\n",
        "  - It generates a replay video of the agent\n",
        "  - It pushes everything to the Hub\n",
        "\n",
        "  :param repo_id: repo_id: id of the model repository from the Hugging Face Hub\n",
        "  :param model: the pytorch model we want to save\n",
        "  :param hyperparameters: training hyperparameters\n",
        "  :param eval_env: evaluation environment\n",
        "  :param video_fps: how many frame per seconds to record our video replay\n",
        "  \"\"\"\n",
        "\n",
        "  _, repo_name = repo_id.split(\"/\")\n",
        "  api = HfApi()\n",
        "\n",
        "  # Step 1: Create the repo\n",
        "  repo_url = api.create_repo(\n",
        "        repo_id=repo_id,\n",
        "        exist_ok=True,\n",
        "  )\n",
        "\n",
        "  with tempfile.TemporaryDirectory() as tmpdirname:\n",
        "    local_directory = Path(tmpdirname)\n",
        "\n",
        "    # Step 2: Save the model\n",
        "    torch.save(model, local_directory / \"model.pt\")\n",
        "\n",
        "    # Step 3: Save the hyperparameters to JSON\n",
        "    with open(local_directory / \"hyperparameters.json\", \"w\") as outfile:\n",
        "      json.dump(hyperparameters, outfile)\n",
        "\n",
        "    # Step 4: Evaluate the model and build JSON\n",
        "    mean_reward, std_reward = evaluate_agent(eval_env,\n",
        "                                            hyperparameters[\"max_t\"],\n",
        "                                            hyperparameters[\"n_evaluation_episodes\"],\n",
        "                                            model)\n",
        "    # Get datetime\n",
        "    eval_datetime = datetime.datetime.now()\n",
        "    eval_form_datetime = eval_datetime.isoformat()\n",
        "\n",
        "    evaluate_data = {\n",
        "          \"env_id\": hyperparameters[\"env_id\"],\n",
        "          \"mean_reward\": mean_reward,\n",
        "          \"n_evaluation_episodes\": hyperparameters[\"n_evaluation_episodes\"],\n",
        "          \"eval_datetime\": eval_form_datetime,\n",
        "    }\n",
        "\n",
        "    # Write a JSON file\n",
        "    with open(local_directory / \"results.json\", \"w\") as outfile:\n",
        "        json.dump(evaluate_data, outfile)\n",
        "\n",
        "    # Step 5: Create the model card\n",
        "    env_name = hyperparameters[\"env_id\"]\n",
        "\n",
        "    metadata = {}\n",
        "    metadata[\"tags\"] = [\n",
        "          env_name,\n",
        "          \"reinforce\",\n",
        "          \"reinforcement-learning\",\n",
        "          \"custom-implementation\",\n",
        "          \"deep-rl-class\"\n",
        "      ]\n",
        "\n",
        "    # Add metrics\n",
        "    eval = metadata_eval_result(\n",
        "        model_pretty_name=repo_name,\n",
        "        task_pretty_name=\"reinforcement-learning\",\n",
        "        task_id=\"reinforcement-learning\",\n",
        "        metrics_pretty_name=\"mean_reward\",\n",
        "        metrics_id=\"mean_reward\",\n",
        "        metrics_value=f\"{mean_reward:.2f} +/- {std_reward:.2f}\",\n",
        "        dataset_pretty_name=env_name,\n",
        "        dataset_id=env_name,\n",
        "      )\n",
        "\n",
        "    # Merges both dictionaries\n",
        "    metadata = {**metadata, **eval}\n",
        "\n",
        "    model_card = f\"\"\"\n",
        "  # **Reinforce** Agent playing **{env_id}**\n",
        "  This is a trained model of a **Reinforce** agent playing **{env_id}** .\n",
        "  To learn to use this model and train yours check Unit 4 of the Deep Reinforcement Learning Course: https://huggingface.co/deep-rl-course/unit4/introduction\n",
        "  \"\"\"\n",
        "\n",
        "    readme_path = local_directory / \"README.md\"\n",
        "    readme = \"\"\n",
        "    if readme_path.exists():\n",
        "        with readme_path.open(\"r\", encoding=\"utf8\") as f:\n",
        "          readme = f.read()\n",
        "    else:\n",
        "      readme = model_card\n",
        "\n",
        "    with readme_path.open(\"w\", encoding=\"utf-8\") as f:\n",
        "      f.write(readme)\n",
        "\n",
        "    # Save our metrics to Readme metadata\n",
        "    metadata_save(readme_path, metadata)\n",
        "\n",
        "    # Step 6: Record a video\n",
        "    video_path =  local_directory / \"replay.mp4\"\n",
        "    record_video(env, model, video_path, video_fps)\n",
        "\n",
        "    # Step 7. Push everything to the Hub\n",
        "    api.upload_folder(\n",
        "          repo_id=repo_id,\n",
        "          folder_path=local_directory,\n",
        "          path_in_repo=\".\",\n",
        "    )\n",
        "\n",
        "    print(f\"Your model is pushed to the Hub. You can view your model here: {repo_url}\")"
      ],
      "metadata": {
        "id": "_TPdq47D7_f_"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "w17w8CxzoURM"
      },
      "source": [
        "### .\n",
        "\n",
        "By using `push_to_hub` **you evaluate, record a replay, generate a model card of your agent and push it to the Hub**.\n",
        "\n",
        "This way:\n",
        "- You can **showcase our work** ๐Ÿ”ฅ\n",
        "- You can **visualize your agent playing** ๐Ÿ‘€\n",
        "- You can **share with the community an agent that others can use** ๐Ÿ’พ\n",
        "- You can **access a leaderboard ๐Ÿ† to see how well your agent is performing compared to your classmates** ๐Ÿ‘‰ https://huggingface.co/spaces/huggingface-projects/Deep-Reinforcement-Learning-Leaderboard\n"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "cWnFC0iZooTw"
      },
      "source": [
        "To be able to share your model with the community there are three more steps to follow:\n",
        "\n",
        "1๏ธโƒฃ (If it's not already done) create an account to HF โžก https://huggingface.co/join\n",
        "\n",
        "2๏ธโƒฃ Sign in and then, you need to store your authentication token from the Hugging Face website.\n",
        "- Create a new token (https://huggingface.co/settings/tokens) **with write role**\n",
        "\n",
        "\n",
        "<img src=\"https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/notebooks/create-token.jpg\" alt=\"Create HF Token\">\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "QB5nIcxR8paT"
      },
      "outputs": [],
      "source": [
        "notebook_login()"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "GyWc1x3-o3xG"
      },
      "source": [
        "If you don't want to use a Google Colab or a Jupyter Notebook, you need to use this command instead: `huggingface-cli login` (or `login`)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "F-D-zhbRoeOm"
      },
      "source": [
        "3๏ธโƒฃ We're now ready to push our trained agent to the ๐Ÿค— Hub ๐Ÿ”ฅ using `package_to_hub()` function"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "UNwkTS65Uq3Q"
      },
      "outputs": [],
      "source": [
        "repo_id = \"\" #TODO Define your repo id {username/Reinforce-{model-id}}\n",
        "push_to_hub(repo_id,\n",
        "                cartpole_policy, # The model we want to save\n",
        "                cartpole_hyperparameters, # Hyperparameters\n",
        "                eval_env, # Evaluation environment\n",
        "                video_fps=30\n",
        "                )"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "jrnuKH1gYZSz"
      },
      "source": [
        "Now that we try the robustness of our implementation, let's try a more complex environment: PixelCopter ๐Ÿš\n",
        "\n",
        "\n"
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "## Second agent: PixelCopter ๐Ÿš\n",
        "\n",
        "### Study the PixelCopter environment ๐Ÿ‘€\n",
        "- [The Environment documentation](https://pygame-learning-environment.readthedocs.io/en/latest/user/games/pixelcopter.html)\n"
      ],
      "metadata": {
        "id": "JNLVmKKVKA6j"
      }
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "JBSc8mlfyin3"
      },
      "outputs": [],
      "source": [
        "env_id = \"Pixelcopter-PLE-v0\"\n",
        "env = gym.make(env_id)\n",
        "eval_env = gym.make(env_id)\n",
        "s_size = env.observation_space.shape[0]\n",
        "a_size = env.action_space.n"
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "print(\"_____OBSERVATION SPACE_____ \\n\")\n",
        "print(\"The State Space is: \", s_size)\n",
        "print(\"Sample observation\", env.observation_space.sample()) # Get a random observation"
      ],
      "metadata": {
        "id": "L5u_zAHsKBy7"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "source": [
        "print(\"\\n _____ACTION SPACE_____ \\n\")\n",
        "print(\"The Action Space is: \", a_size)\n",
        "print(\"Action Space Sample\", env.action_space.sample()) # Take a random action"
      ],
      "metadata": {
        "id": "D7yJM9YXKNbq"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "NNWvlyvzalXr"
      },
      "source": [
        "The observation space (7) ๐Ÿ‘€:\n",
        "- player y position\n",
        "- player velocity\n",
        "- player distance to floor\n",
        "- player distance to ceiling\n",
        "- next block x distance to player\n",
        "- next blocks top y location\n",
        "- next blocks bottom y location\n",
        "\n",
        "The action space(2) ๐ŸŽฎ:\n",
        "- Up (press accelerator)\n",
        "- Do nothing (don't press accelerator)\n",
        "\n",
        "The reward function ๐Ÿ’ฐ:\n",
        "- For each vertical block it passes through it gains a positive reward of +1. Each time a terminal state reached it receives a negative reward of -1."
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "### Define the new Policy ๐Ÿง \n",
        "- We need to have a deeper neural network since the environment is more complex"
      ],
      "metadata": {
        "id": "aV1466QP8crz"
      }
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "I1eBkCiX2X_S"
      },
      "outputs": [],
      "source": [
        "class Policy(nn.Module):\n",
        "    def __init__(self, s_size, a_size, h_size):\n",
        "        super(Policy, self).__init__()\n",
        "        # Define the three layers here\n",
        "\n",
        "    def forward(self, x):\n",
        "        # Define the forward process here\n",
        "        return F.softmax(x, dim=1)\n",
        "\n",
        "    def act(self, state):\n",
        "        state = torch.from_numpy(state).float().unsqueeze(0).to(device)\n",
        "        probs = self.forward(state).cpu()\n",
        "        m = Categorical(probs)\n",
        "        action = m.sample()\n",
        "        return action.item(), m.log_prob(action)"
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "#### Solution"
      ],
      "metadata": {
        "id": "47iuAFqV8Ws-"
      }
    },
    {
      "cell_type": "code",
      "source": [
        "class Policy(nn.Module):\n",
        "    def __init__(self, s_size, a_size, h_size):\n",
        "        super(Policy, self).__init__()\n",
        "        self.fc1 = nn.Linear(s_size, h_size)\n",
        "        self.fc2 = nn.Linear(h_size, h_size*2)\n",
        "        self.fc3 = nn.Linear(h_size*2, a_size)\n",
        "\n",
        "    def forward(self, x):\n",
        "        x = F.relu(self.fc1(x))\n",
        "        x = F.relu(self.fc2(x))\n",
        "        x = self.fc3(x)\n",
        "        return F.softmax(x, dim=1)\n",
        "\n",
        "    def act(self, state):\n",
        "        state = torch.from_numpy(state).float().unsqueeze(0).to(device)\n",
        "        probs = self.forward(state).cpu()\n",
        "        m = Categorical(probs)\n",
        "        action = m.sample()\n",
        "        return action.item(), m.log_prob(action)"
      ],
      "metadata": {
        "id": "wrNuVcHC8Xu7"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "SM1QiGCSbBkM"
      },
      "source": [
        "### Define the hyperparameters โš™๏ธ\n",
        "- Because this environment is more complex.\n",
        "- Especially for the hidden size, we need more neurons."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "y0uujOR_ypB6"
      },
      "outputs": [],
      "source": [
        "pixelcopter_hyperparameters = {\n",
        "    \"h_size\": 64,\n",
        "    \"n_training_episodes\": 50000,\n",
        "    \"n_evaluation_episodes\": 10,\n",
        "    \"max_t\": 10000,\n",
        "    \"gamma\": 0.99,\n",
        "    \"lr\": 1e-4,\n",
        "    \"env_id\": env_id,\n",
        "    \"state_space\": s_size,\n",
        "    \"action_space\": a_size,\n",
        "}"
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "###  Train it\n",
        "- We're now ready to train our agent ๐Ÿ”ฅ."
      ],
      "metadata": {
        "id": "wyvXTJWm9GJG"
      }
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "7mM2P_ckysFE"
      },
      "outputs": [],
      "source": [
        "# Create policy and place it to the device\n",
        "# torch.manual_seed(50)\n",
        "pixelcopter_policy = Policy(pixelcopter_hyperparameters[\"state_space\"], pixelcopter_hyperparameters[\"action_space\"], pixelcopter_hyperparameters[\"h_size\"]).to(device)\n",
        "pixelcopter_optimizer = optim.Adam(pixelcopter_policy.parameters(), lr=pixelcopter_hyperparameters[\"lr\"])"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "v1HEqP-fy-Rf"
      },
      "outputs": [],
      "source": [
        "scores = reinforce(pixelcopter_policy,\n",
        "                   pixelcopter_optimizer,\n",
        "                   pixelcopter_hyperparameters[\"n_training_episodes\"],\n",
        "                   pixelcopter_hyperparameters[\"max_t\"],\n",
        "                   pixelcopter_hyperparameters[\"gamma\"],\n",
        "                   1000)"
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "### Publish our trained model on the Hub ๐Ÿ”ฅ"
      ],
      "metadata": {
        "id": "8kwFQ-Ip85BE"
      }
    },
    {
      "cell_type": "code",
      "source": [
        "repo_id = \"\" #TODO Define your repo id {username/Reinforce-{model-id}}\n",
        "push_to_hub(repo_id,\n",
        "                pixelcopter_policy, # The model we want to save\n",
        "                pixelcopter_hyperparameters, # Hyperparameters\n",
        "                eval_env, # Evaluation environment\n",
        "                video_fps=30\n",
        "                )"
      ],
      "metadata": {
        "id": "6PtB7LRbTKWK"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "7VDcJ29FcOyb"
      },
      "source": [
        "## Some additional challenges ๐Ÿ†\n",
        "The best way to learn **is to try things on your own**! As you saw, the current agent is not doing great. As a first suggestion, you can train for more steps. But also trying to find better parameters.\n",
        "\n",
        "In the [Leaderboard](https://huggingface.co/spaces/huggingface-projects/Deep-Reinforcement-Learning-Leaderboard) you will find your agents. Can you get to the top?\n",
        "\n",
        "Here are some ideas to achieve so:\n",
        "* Train more steps\n",
        "* Try different hyperparameters by looking at what your classmates have done ๐Ÿ‘‰ https://huggingface.co/models?other=reinforce\n",
        "* **Push your new trained model** on the Hub ๐Ÿ”ฅ\n",
        "* **Improving the implementation for more complex environments** (for instance, what about changing the network to a Convolutional Neural Network to handle\n",
        "frames as observation)?"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "x62pP0PHdA-y"
      },
      "source": [
        "________________________________________________________________________\n",
        "\n",
        "**Congrats on finishing this unit**!ย There was a lot of information.\n",
        "And congrats on finishing the tutorial. You've just coded your first Deep Reinforcement Learning agent from scratch using PyTorch and shared it on the Hub ๐Ÿฅณ.\n",
        "\n",
        "Don't hesitate to iterate on this unit **by improving the implementation for more complex environments** (for instance, what about changing the network to a Convolutional Neural Network to handle\n",
        "frames as observation)?\n",
        "\n",
        "In the next unit, **we're going to learn more about Unity MLAgents**, by training agents in Unity environments. This way, you will be ready to participate in the **AI vs AI challenges where you'll train your agents\n",
        "to compete against other agents in a snowball fight and a soccer game.**\n",
        "\n",
        "Sounds fun? See you next time!\n",
        "\n",
        "Finally, we would love **to hear what you think of the course and how we can improve it**. If you have some feedback then, please ๐Ÿ‘‰  [fill this form](https://forms.gle/BzKXWzLAGZESGNaE9)\n",
        "\n",
        "See you in Unit 5! ๐Ÿ”ฅ\n",
        "\n",
        "### Keep Learning, stay awesome ๐Ÿค—\n",
        "\n"
      ]
    }
  ],
  "metadata": {
    "accelerator": "GPU",
    "colab": {
      "private_outputs": true,
      "provenance": [],
      "collapsed_sections": [
        "BPLwsPajb1f8",
        "L_WSo0VUV99t",
        "mjY-eq3eWh9O",
        "JoTC9o2SczNn",
        "gfGJNZBUP7Vn",
        "YB0Cxrw1StrP",
        "47iuAFqV8Ws-",
        "x62pP0PHdA-y"
      ]
    },
    "gpuClass": "standard",
    "kernelspec": {
      "display_name": "Python 3 (ipykernel)",
      "language": "python",
      "name": "python3"
    },
    "language_info": {
      "codemirror_mode": {
        "name": "ipython",
        "version": 3
      },
      "file_extension": ".py",
      "mimetype": "text/x-python",
      "name": "python",
      "nbconvert_exporter": "python",
      "pygments_lexer": "ipython3",
      "version": "3.8.10"
    }
  },
  "nbformat": 4,
  "nbformat_minor": 0
}