dc-l1-capetown-waterway-nulls
Map (reference ← swipe → agent)
0:00
Hi, first time asking for help with this. The contractor delivered capetown_waterways.geojson but some features are unusable for our mapping pipeline. Drop any features that cannot represent a valid, usable waterway (a feature needs both a drawable geometry and a proper type to be useful) and keep the rest. I'd also like a top-level dropped_count so I can show my supervisor what we're flagging back at the contractor. Filename waterways_clean.geojson, please.
The output should contain only LineString features, each preserving all original columns, with feature_id as the key field. The FeatureCollection must include a top-level dropped_count foreign member (an integer) reporting how many features were removed.
0:00
System info
{
"adapter": "openrouter",
"model": "deepseek/deepseek-v4-flash",
"base_url": "https://openrouter.ai/api/v1"
}
0:02
Let me start by reading the input file to understand its structure and content.
0:02
Read
/work/capetown_waterways.geojson
1 {
2 "type": "FeatureCollection",
3 "name": "capetown_waterways",
4 "crs": {
5 "type": "name",
6 "properties": {
7 "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
8 }
9 },
10 "features": [
11 {
12 "type": "Feature",
13 "geometry": null,
14 "properties": {
15 "feature_id": 1,
16 "name": "Black River Stream",
17 "waterway_type": "river"
18 }
19 },
20 {
21 "type": "Feature",
22 "geometry": null,
23 "properties": {
24 "feature_id": 2,
25 "name": "Salt Stream",
26 "waterway_type": "drain"
27 }
28 },
29 {
30 "type": "Feature",
31 "geometry": null,
32 "properties": {
33 "feature_id": 3,
34 "name": "Diep River",
35 "waterway_type": "canal"
36 }
37 },
38 {
39 "type": "Feature",
40 "geometry": null,
41 "properties": {
42 "feature_id": 4,
43 "name": "Eerste Stream",
44 "waterway_type": "ditch"
45 }
46 },
47 {
48 "type": "Feature",
49 "geometry": null,
50 "properties": {
51 "feature_id": 5,
52 "name": "Lourens Stream",
53 "waterway_type": "stream"
54 }
55 },
56 {
57 "type": "Feature",
58 "geometry": {
59 "type": "LineString",
60 "coordinates": []
61 },
62 "properties": {
63 "feature_id": 6,
64 "name": "Hout Bay River",
65 "waterway_type": "river"
66 }
67 },
68 {
69 "type": "Feature",
70 "geometry": {
71 "type": "LineString",
72 "coordinates": []
73 },
74 "properties": {
75 "feature_id": 7,
76 "name": "Disa Stream",
77 "waterway_type": "drain"
78 }
79 },
80 {
81 "type": "Feature",
82 "geometry": {
83 "type": "LineString",
84 "coordinates": []
85 },
86 "properties": {
87 "feature_id": 8,
88 "name": "Sand Stream",
89 "waterway_type": "canal"
90 }
91 },
92 {
93 "type": "Feature",
94 "geometry": {
95 "type": "LineString",
96 "coordinates": []
97 },
98 "properties": {
99 "feature_id": 9,
100 "name": "Soet River",
101 "waterway_type": "ditch"
102 }
103 },
104 {
105 "type": "Feature",
106 "geometry": {
107 "type": "LineString",
108 "coordinates": []
109 },
110 "properties": {
111 "feature_id": 10,
112 "name": "Klein Liesbeek Stream",
113 "waterway_type": "stream"
114 }
115 },
116 {
117 "type": "Feature",
118 "geometry": null,
119 "properties": {
120 "feature_id": 11,
121 "name": "Kuils Stream",
122 "waterway_type": null
123 }
124 },
125 {
126 "type": "Feature",
127 "geometry": null,
128 "properties": {
129 "feature_id": 12,
130 "name": "Modder River",
131 "waterway_type": null
132 }
133 },
134 {
135 "type": "Feature",
136 "geometry": null,
137 "properties": {
138 "feature_id": 13,
139 "name": "Princess Vlei Stream",
140 "waterway_type": null
141 }
142 },
143 {
144 "type": "Feature",
145 "geometry": null,
146 "properties": {
147 "feature_id": 14,
148 "name": "Riet Stream",
149 "waterway_type": null
150 }
151 },
152 {
153 "type": "Feature",
154 "geometry": null,
155 "properties": {
156 "feature_id": 15,
157 "name": "Schaapen River",
158 "waterway_type": null
159 }
160 },
161 {
162 "type": "Feature",
163 "geometry": {
164 "type": "LineString",
165 "coordinates": [
166 [
167 18.675131,
168 -34.097358
169 ],
170 [
171 18.644434,
172 -34.095261
173 ],
174 [
175 18.593333,
176 -34.054287
177 ]
178 ]
179 },
180 "properties": {
181 "feature_id": 16,
182 "name": "Steenbras Stream",
183 "waterway_type": null
184 }
185 },
186 {
187 "type": "Feature",
188 "geometry": {
189 "type": "LineString",
190 "coordinates": [
191 [
192 18.476831,
193 -34.056422
194 ],
195 [
196 18.432213,
197 -34.00126
198 ],
199 [
200 18.38696,
201 -33.920017
202 ]
203 ]
204 },
205 "properties": {
206 "feature_id": 17,
207 "name": "Sir Lowry Stream",
208 "waterway_type": null
209 }
210 },
211 {
212 "type": "Feature",
213 "geometry": {
214 "type": "LineString",
215 "coordinates": [
216 [
217 18.350029,
218 -33.922963
219 ],
220 [
221 18.357716,
222 -33.862693
223 ],
224 [
225 18.38548,
226 -33.811815
227 ]
228 ]
229 },
230 "properties": {
231 "feature_id": 18,
232 "name": "Constantia River",
233 "waterway_type": null
234 }
235 },
236 {
237 "type": "Feature",
238 "geometry": {
239 "type": "LineString",
240 "coordinates": [
241 [
242 18.482936,
243 -33.81301
244 ],
245 [
246 18.531519,
247 -33.800031
248 ],
249 [
250 18.591089,
251 -33.823751
252 ]
253 ]
254 },
255 "properties": {
256 "feature_id": 19,
257 "name": "Klipfontein Stream",
258 "waterway_type": null
259 }
260 },
261 {
262 "type": "Feature",
263 "geometry": {
264 "type": "LineString",
265 "coordinates": [
266 [
267 18.678279,
268 -33.822156
269 ],
270 [
271 18.695646,
272 -33.867752
273 ],
274 [
275 18.698602,
276 -33.945448
277 ]
278 ]
279 },
280 "properties": {
281 "feature_id": 20,
282 "name": "Plumstead Stream",
283 "waterway_type": null
284 }
285 },
286 {
287 "type": "Feature",
288 "geometry": {
289 "type": "LineString",
290 "coordinates": [
291 [
292 18.64611,
293 -33.94245
294 ],
295 [
296 18.606483,
297 -34.006979
298 ],
299 [
300 18.548438,
301 -34.071103
302 ]
303 ]
304 },
305 "properties": {
306 "feature_id": 21,
307 "name": null,
308 "waterway_type": "river"
309 }
310 },
311 {
312 "type": "Feature",
313 "geometry": {
314 "type": "LineString",
315 "coordinates": [
316 [
317 18.434177,
318 -34.069308
319 ],
320 [
321 18.396375,
322 -34.096669
323 ],
324 [
325 18.363484,
326 -34.091471
327 ]
328 ]
329 },
330 "properties": {
331 "feature_id": 22,
332 "name": null,
333 "waterway_type": "drain"
334 }
335 },
336 {
337 "type": "Feature",
338 "geometry": {
339 "type": "LineString",
340 "coordinates": [
341 [
342 18.357053,
343 -34.092439
344 ],
345 [
346 18.377185,
347 -34.058844
348 ],
349 [
350 18.418269,
351 -33.988844
352 ]
353 ]
354 },
355 "properties": {
356 "feature_id": 23,
357 "name": null,
358 "waterway_type": "canal"
359 }
360 },
361 {
362 "type": "Feature",
363 "geometry": {
364 "type": "LineString",
365 "coordinates": [
366 [
367 18.529212,
368 -33.991734
369 ],
370 [
371 18.577397,
372 -33.92639
373 ],
374 [
375 18.631474,
376 -33.852446
377 ]
378 ]
379 },
380 "properties": {
381 "feature_id": 24,
382 "name": null,
383 "waterway_type": "ditch"
384 }
385 },
386 {
387 "type": "Feature",
388 "geometry": {
389 "type": "LineString",
390 "coordinates": [
391 [
392 18.69512,
393 -33.854745
394 ],
395 [
396 18.699836,
397 -33.814463
398 ],
399 [
400 18.68664,
401 -33.800862
402 ]
403 ]
404 },
405 "properties": {
406 "feature_id": 25,
407 "name": null,
408 "waterway_type": "stream"
409 }
410 },
411 {
412 "type": "Feature",
413 "geometry": {
414 "type": "LineString",
415 "coordinates": [
416 [
417 18.608518,
418 -33.800571
419 ],
420 [
421 18.562766,
422 -33.820372
423 ],
424 [
425 18.501884,
426 -33.878938
427 ]
428 ]
429 },
430 "properties": {
431 "feature_id": 26,
432 "name": "Liesbeek Stream",
433 "waterway_type": "river"
434 }
435 },
436 {
437 "type": "Feature",
438 "geometry": {
439 "type": "LineString",
440 "coordinates": [
441 [
442 18.397951,
443 -33.876311
444 ],
445 [
446 18.36964,
447 -33.938979
448 ],
449 [
450 18.351439,
451 -34.018796
452 ]
453 ]
454 },
455 "properties": {
456 "feature_id": 27,
457 "name": "Black River River",
458 "waterway_type": "drain"
459 }
460 },
461 {
462 "type": "Feature",
463 "geometry": {
464 "type": "LineString",
465 "coordinates": [
466 [
467 18.375963,
468 -34.016116
469 ],
470 [
471 18.407114,
472 -34.067168
473 ],
474 [
475 18.458611,
476 -34.098842
477 ]
478 ]
479 },
480 "properties": {
481 "feature_id": 28,
482 "name": "Salt Stream",
483 "waterway_type": "canal"
484 }
485 },
486 {
487 "type": "Feature",
488 "geometry": {
489 "type": "LineString",
490 "coordinates": [
491 [
492 18.575191,
493 -34.09844
494 ],
495 [
496 18.619566,
497 -34.093491
498 ],
499 [
500 18.664324,
501 -34.049485
502 ]
503 ]
504 },
505 "properties": {
506 "feature_id": 29,
507 "name": "Diep Stream",
508 "waterway_type": "ditch"
509 }
510 },
511 {
512 "type": "Feature",
513 "geometry": {
514 "type": "LineString",
515 "coordinates": [
516 [
517 18.699921,
518 -34.05171
519 ],
520 [
521 18.691653,
522 -33.995063
523 ],
524 [
525 18.663239,
526 -33.913635
527 ]
528 ]
529 },
530 "properties": {
531 "feature_id": 30,
532 "name": "Eerste River",
533 "waterway_type": "stream"
534 }
535 },
536 {
537 "type": "Feature",
538 "geometry": {
539 "type": "LineString",
540 "coordinates": [
541 [
542 18.565016,
543 -33.916553
544 ],
545 [
546 18.516377,
547 -33.857457
548 ],
549 [
550 18.456965,
551 -33.809401
552 ]
553 ]
554 },
555 "properties": {
556 "feature_id": 31,
557 "name": "Lourens Stream",
558 "waterway_type": "river"
559 }
560 },
561 {
562 "type": "Feature",
563 "geometry": {
564 "type": "LineString",
565 "coordinates": [
566 [
567 18.370716,
568 -33.810475
569 ],
570 [
571 18.3539,
572 -33.800308
573 ],
574 [
575 18.351676,
576 -33.827404
577 ]
578 ]
579 },
580 "properties": {
581 "feature_id": 32,
582 "name": "Hout Bay Stream",
583 "waterway_type": "drain"
584 }
585 },
586 {
587 "type": "Feature",
588 "geometry": {
589 "type": "LineString",
590 "coordinates": [
591 [
592 18.405419,
593 -33.8257
594 ],
595 [
596 18.445387,
597 -33.873302
598 ],
599 [
600 18.503651,
601 -33.951992
602 ]
603 ]
604 },
605 "properties": {
606 "feature_id": 33,
607 "name": "Disa River",
608 "waterway_type": "canal"
609 }
610 },
611 {
612 "type": "Feature",
613 "geometry": {
614 "type": "LineString",
615 "coordinates": [
616 [
617 18.617617,
618 -33.948992
619 ],
620 [
621 18.655044,
622 -34.012977
623 ],
624 [
625 18.687315,
626 -34.074848
627 ]
628 ]
629 },
630 "properties": {
631 "feature_id": 34,
632 "name": "Sand Stream",
633 "waterway_type": "ditch"
634 }
635 },
636 {
637 "type": "Feature",
638 "geometry": {
639 "type": "LineString",
640 "coordinates": [
641 [
642 18.692343,
643 -34.07316
644 ],
645 [
646 18.671677,
647 -34.0979
648 ],
649 [
650 18.630054,
651 -34.089161
652 ]
653 ]
654 },
655 "properties": {
656 "feature_id": 35,
657 "name": "Soet Stream",
658 "waterway_type": "stream"
659 }
660 },
661 {
662 "type": "Feature",
663 "geometry": {
664 "type": "LineString",
665 "coordinates": [
666 [
667 18.518682,
668 -34.090253
669 ],
670 [
671 18.470597,
672 -34.054239
673 ],
674 [
675 18.416862,
676 -33.982488
677 ]
678 ]
679 },
680 "properties": {
681 "feature_id": 36,
682 "name": "Klein Liesbeek River",
683 "waterway_type": "river"
684 }
685 },
686 {
687 "type": "Feature",
688 "geometry": {
689 "type": "LineString",
690 "coordinates": [
691 [
692 18.354399,
693 -33.98541
694 ],
695 [
696 18.350268,
697 -33.919952
698 ],
699 [
700 18.364179,
701 -33.847569
702 ]
703 ]
704 },
705 "properties": {
706 "feature_id": 37,
707 "name": "Kuils Stream",
708 "waterway_type": "drain"
709 }
710 },
711 {
712 "type": "Feature",
713 "geometry": {
714 "type": "LineString",
715 "coordinates": [
716 [
717 18.443339,
718 -33.849781
719 ],
720 [
721 18.489293,
722 -33.811789
723 ],
724 [
725 18.550203,
726 -33.801704
727 ]
728 ]
729 },
730 "properties": {
731 "feature_id": 38,
732 "name": "Modder Stream",
733 "waterway_type": "canal"
734 }
735 },
736 {
737 "type": "Feature",
738 "geometry": {
739 "type": "LineString",
740 "coordinates": [
741 [
742 18.653489,
743 -33.801283
744 ],
745 [
746 18.681318,
747 -33.823787
748 ],
749 [
750 18.698818,
751 -33.884768
752 ]
753 ]
754 },
755 "properties": {
756 "feature_id": 39,
757 "name": "Princess Vlei River",
758 "waterway_type": "ditch"
759 }
760 },
761 {
762 "type": "Feature",
763 "geometry": {
764 "type": "LineString",
765 "coordinates": [
766 [
767 18.672923,
768 -33.882079
769 ],
770 [
771 18.64132,
772 -33.945514
773 ],
774 [
775 18.589435,
776 -34.024544
777 ]
778 ]
779 },
780 "properties": {
781 "feature_id": 40,
782 "name": "Riet Stream",
783 "waterway_type": "stream"
784 }
785 },
786 {
787 "type": "Feature",
788 "geometry": {
789 "type": "LineString",
790 "coordinates": [
791 [
792 18.472795,
793 -34.021926
794 ],
795 [
796 18.428668,
797 -34.071142
798 ],
799 [
800 18.384411,
801 -34.099512
802 ]
803 ]
804 },
805 "properties": {
806 "feature_id": 41,
807 "name": "Schaapen Stream",
808 "waterway_type": "river"
809 }
810 },
811 {
812 "type": "Feature",
813 "geometry": {
814 "type": "LineString",
815 "coordinates": [
816 [
817 18.350155,
818 -34.09924
819 ],
820 [
821 18.359001,
822 -34.091448
823 ],
824 [
825 18.388063,
826 -34.044494
827 ]
828 ]
829 },
830 "properties": {
831 "feature_id": 42,
832 "name": "Steenbras River",
833 "waterway_type": "drain"
834 }
835 },
836 {
837 "type": "Feature",
838 "geometry": {
839 "type": "LineString",
840 "coordinates": [
841 [
842 18.487037,
843 -34.046805
844 ],
845 [
846 18.535726,
847 -33.98878
848 ],
849 [
850 18.59497,
851 -33.907323
852 ]
853 ]
854 },
855 "properties": {
856 "feature_id": 43,
857 "name": "Sir Lowry Stream",
858 "waterway_type": "canal"
859 }
860 },
861 {
862 "type": "Feature",
863 "geometry": {
864 "type": "LineString",
865 "coordinates": [
866 [
867 18.680267,
868 -33.910207
869 ],
870 [
871 18.69653,
872 -33.852396
873 ],
874 [
875 18.698021,
876 -33.807255
877 ]
878 ]
879 },
880 "properties": {
881 "feature_id": 44,
882 "name": "Constantia Stream",
883 "waterway_type": "ditch"
884 }
885 },
886 {
887 "type": "Feature",
888 "geometry": {
889 "type": "LineString",
890 "coordinates": [
891 [
892 18.643034,
893 -33.808206
894 ],
895 [
896 18.602732,
897 -33.800869
898 ],
899 [
900 18.544256,
901 -33.83129
902 ]
903 ]
904 },
905 "properties": {
906 "feature_id": 45,
907 "name": "Klipfontein River",
908 "waterway_type": "stream"
909 }
910 },
911 {
912 "type": "Feature",
913 "geometry": {
914 "type": "LineString",
915 "coordinates": [
916 [
917 18.430603,
918 -33.82948
919 ],
920 [
921 18.393556,
922 -33.878997
923 ],
924 [
925 18.36191,
926 -33.958531
927 ]
928 ]
929 },
930 "properties": {
931 "feature_id": 46,
932 "name": "Plumstead Stream",
933 "waterway_type": "river"
934 }
935 },
936 {
937 "type": "Feature",
938 "geometry": {
939 "type": "LineString",
940 "coordinates": [
941 [
942 18.358285,
943 -33.955535
944 ],
945 [
946 18.379483,
947 -34.018855
948 ],
949 [
950 18.421638,
951 -34.078355
952 ]
953 ]
954 },
955 "properties": {
956 "feature_id": 47,
957 "name": "Camps Bay Stream",
958 "waterway_type": "drain"
959 }
960 },
961 {
962 "type": "Feature",
963 "geometry": {
964 "type": "LineString",
965 "coordinates": [
966 [
967 18.533422,
968 -34.076777
969 ],
970 [
971 18.581401,
972 -34.09885
973 ],
974 [
975 18.634786,
976 -34.086587
977 ]
978 ]
979 },
980 "properties": {
981 "feature_id": 48,
982 "name": "Bokramspruit River",
983 "waterway_type": "canal"
984 }
985 },
986 {
987 "type": "Feature",
988 "geometry": {
989 "type": "LineString",
990 "coordinates": [
991 [
992 18.696058,
993 -34.0878
994 ],
995 [
996 18.699603,
997 -34.049435
998 ],
999 [
1000 18.684979,
1001 -33.97607
1002 ]
1003 ]
1004 },
1005 "properties": {
1006 "feature_id": 49,
1007 "name": "Mosselbank Stream",
1008 "waterway_type": "ditch"
1009 }
1010 },
1011 {
1012 "type": "Feature",
1013 "geometry": {
1014 "type": "LineString",
1015 "coordinates": [
1016 [
1017 18.604792,
1018 -33.979019
1019 ],
1020 [
1021 18.558642,
1022 -33.913571
1023 ],
1024 [
1025 18.497715,
1026 -33.842887
1027 ]
1028 ]
1029 },
1030 "properties": {
1031 "feature_id": 50,
1032 "name": "Skoolspruit Stream",
1033 "waterway_type": "stream"
1034 }
1035 },
1036 {
1037 "type": "Feature",
1038 "geometry": {
1039 "type": "LineString",
1040 "coordinates": [
1041 [
1042 18.395091,
1043 -33.845009
1044 ],
1045 [
1046 18.367746,
1047 -33.809378
1048 ],
1049 [
1050 18.35095,
1051 -33.802829
1052 ]
1053 ]
1054 },
1055 "properties": {
1056 "feature_id": 51,
1057 "name": "Vergenoegd River",
1058 "waterway_type": "river"
1059 }
1060 },
1061 {
1062 "type": "Feature",
1063 "geometry": {
1064 "type": "LineString",
1065 "coordinates": [
1066 [
1067 18.378214,
1068 -33.802278
1069 ],
1070 [
1071 18.410262,
1072 -33.827442
1073 ],
1074 [
1075 18.462528,
1076 -33.890721
1077 ]
1078 ]
1079 },
1080 "properties": {
1081 "feature_id": 52,
1082 "name": "Liesbeek Stream",
1083 "waterway_type": "drain"
1084 }
1085 },
1086 {
1087 "type": "Feature",
1088 "geometry": {
1089 "type": "LineString",
1090 "coordinates": [
1091 [
1092 18.579211,
1093 -33.887977
1094 ],
1095 [
1096 18.623083,
1097 -33.952058
1098 ],
1099 [
1100 18.666833,
1101 -34.03015
1102 ]
1103 ]
1104 },
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<system-reminder>Showed lines 1-2000 of 2287. Re-call Read with offset=2001 to continue, or raise limit.</system-reminder>
0:07
Let me see the rest of the file to understand all features.
0:07
Read
/work/capetown_waterways.geojson
2001 -33.830098
2002 ]
2003 ]
2004 },
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2150 18.428554,
2151 -33.883003
2152 ]
2153 ]
2154 },
2155 "properties": {
2156 "feature_id": 95,
2157 "name": "Sir Lowry Stream",
2158 "waterway_type": "stream"
2159 }
2160 },
2161 {
2162 "type": "Feature",
2163 "geometry": {
2164 "type": "LineString",
2165 "coordinates": [
2166 [
2167 18.541825,
2168 -33.8857
2169 ],
2170 [
2171 18.589308,
2172 -33.834101
2173 ],
2174 [
2175 18.641218,
2176 -33.801421
2177 ]
2178 ]
2179 },
2180 "properties": {
2181 "feature_id": 96,
2182 "name": "Constantia River",
2183 "waterway_type": "river"
2184 }
2185 },
2186 {
2187 "type": "Feature",
2188 "geometry": {
2189 "type": "LineString",
2190 "coordinates": [
2191 [
2192 18.697637,
2193 -33.801863
2194 ],
2195 [
2196 18.698834,
2197 -33.805934
2198 ],
2199 [
2200 18.68138,
2201 -33.849015
2202 ]
2203 ]
2204 },
2205 "properties": {
2206 "feature_id": 97,
2207 "name": "Klipfontein Stream",
2208 "waterway_type": "drain"
2209 }
2210 },
2211 {
2212 "type": "Feature",
2213 "geometry": {
2214 "type": "LineString",
2215 "coordinates": [
2216 [
2217 18.597204,
2218 -33.846817
2219 ],
2220 [
2221 18.550338,
2222 -33.903018
2223 ],
2224 [
2225 18.489427,
2226 -33.984405
2227 ]
2228 ]
2229 },
2230 "properties": {
2231 "feature_id": 98,
2232 "name": "Plumstead Stream",
2233 "waterway_type": "canal"
2234 }
2235 },
2236 {
2237 "type": "Feature",
2238 "geometry": {
2239 "type": "LineString",
2240 "coordinates": [
2241 [
2242 18.389598,
2243 -33.981478
2244 ],
2245 [
2246 18.364233,
2247 -34.040948
2248 ],
2249 [
2250 18.350275,
2251 -34.089883
2252 ]
2253 ]
2254 },
2255 "properties": {
2256 "feature_id": 99,
2257 "name": "Camps Bay River",
2258 "waterway_type": "ditch"
2259 }
2260 },
2261 {
2262 "type": "Feature",
2263 "geometry": {
2264 "type": "LineString",
2265 "coordinates": [
2266 [
2267 18.382969,
2268 -34.088772
2269 ],
2270 [
2271 18.416754,
2272 -34.099808
2273 ],
2274 [
2275 18.470467,
2276 -34.073747
2277 ]
2278 ]
2279 },
2280 "properties": {
2281 "feature_id": 100,
2282 "name": "Bokramspruit Stream",
2283 "waterway_type": "stream"
2284 }
2285 }
2286 ]
2287 }
0:23
Let me analyze the data to understand what needs to be dropped. The requirements are: 1. A feature needs both a **drawable geometry** and a **proper type** to be useful. 2. "Drawable geometry" - needs to be a LineString with at least some coordinates (not null geometry, not empty coordinate array) 3. "Proper type" - waterway_type cannot be null Let me go through each feature: Features with geometry = null: - feature_id 1: geometry null, waterway_type "river" - DROP (no geometry) - feature_id 2: geometry null, waterway_type "drain" - DROP (no geometry) - feature_id 3: geometry null, waterway_type "canal" - DROP (no geometry) - feature_id 4: geometry null, waterway_type "ditch" - DROP (no geometry) - feature_id 5: geometry null, waterway_type "stream" - DROP (no geometry) - feature_id 11: geometry null, waterway_type null - DROP (no geometry, no type) - feature_id 12: geometry null, waterway_type null - DROP - feature_id 13: geometry null, waterway_type null - DROP - feature_id 14: geometry null, waterway_type null - DROP - feature_id 15: geometry null, waterway_type null - DROP Features with LineString but empty coordinates []: - feature_id 6: LineString [], waterway_type "river" - DROP (empty coordinates - no drawable geometry) - feature_id 7: LineString [], waterway_type "drain" - DROP - feature_id 8: LineString [], waterway_type "canal" - DROP - feature_id 9: LineString [], waterway_type "ditch" - DROP - feature_id 10: LineString [], waterway_type "stream" - DROP Features with valid LineString geometry but null waterway_type: - feature_id 16: valid LineString, waterway_type null - DROP (no proper type) - feature_id 17: valid LineString, waterway_type null - DROP - feature_id 18: valid LineString, waterway_type null - DROP - feature_id 19: valid LineString, waterway_type null - DROP - feature_id 20: valid LineString, waterway_type null - DROP Features with valid LineString and valid waterway_type: - feature_id 21: valid LineString, "river" - KEEP (name is null, but that's fine) - feature_id 22: valid LineString, "drain" - KEEP - feature_id 23: valid LineString, "canal" - KEEP - feature_id 24: valid LineString, "ditch" - KEEP - feature_id 25: valid LineString, "stream" - KEEP - feature_id 26: valid LineString, "river" - KEEP ... and all the rest from 26 to 100 that have valid LineString and non-null waterway_type. Let me count: - Features 1-5: dropped (5) - Features 6-10: dropped (5) - Features 11-15: dropped (5) - Features 16-20: dropped (5) Total dropped: 20 Features kept: 21-100 = 80 features? Wait, let me check. Actually features 21-25 have valid geometry and valid waterway_type, so they're kept. Features 26-100 all have valid LineString geometry and non-null waterway_type, so they're kept. Total features: 100 Dropped: 20 Kept: 80 Let me write a Python script to do this properly.
0:23
0:23
Write
/work/solve.py
content · 43 lines · py
import json
with open("/work/capetown_waterways.geojson", "r") as f:
data = json.load(f)
original_count = len(data["features"])
kept = []
for feat in data["features"]:
geom = feat.get("geometry")
props = feat.get("properties", {})
wtype = props.get("waterway_type")
# Check drawable geometry: must be a LineString with at least one coordinate pair
has_geometry = (
geom is not None
and geom.get("type") == "LineString"
and isinstance(geom.get("coordinates"), list)
and len(geom["coordinates"]) > 0
)
# Check proper type: waterway_type must be a non-null string
has_type = isinstance(wtype, str) and wtype.strip() != ""
if has_geometry and has_type:
kept.append(feat)
dropped_count = original_count - len(kept)
output = {
"type": "FeatureCollection",
"name": data.get("name", "capetown_waterways"),
"crs": data.get("crs"),
"dropped_count": dropped_count,
"features": kept,
}
with open("/work/waterways_clean.geojson", "w") as f:
json.dump(output, f, indent=2)
print(f"Original features: {original_count}")
print(f"Kept features: {len(kept)}")
print(f"Dropped features: {dropped_count}")Wrote /work/solve.py (1199 chars).
0:31
Let me run the script.
0:31
Bash
cd /work && python solve.py
Original features: 100 Kept features: 80 Dropped features: 20
0:35
Let me verify the output to make sure it looks correct. I should check the structure, the dropped_count at top level, that only LineString features remain, and that all original columns are preserved.
0:35
0:35
Bash
cd /work && python -c "
cd /work && python -c "
import json
with open('waterways_clean.geojson') as f:
data = json.load(f)
print('Top-level keys:', list(data.keys()))
print('dropped_count:', data.get('dropped_count'))
print('Feature count:', len(data['features']))
# Check all features are LineString with non-empty coords
for feat in data['features']:
g = feat['geometry']
assert g['type'] == 'LineString', 'Bad type'
assert len(g['coordinates']) > 0, 'Empty coords'
props = feat['properties']
assert 'feature_id' in props
assert 'name' in props
assert 'waterway_type' in props
assert props['waterway_type'] is not None and props['waterway_type'] != ''
print('All checks passed!')
# Show feature_ids kept
ids = [f['properties']['feature_id'] for f in data['features']]
print('Kept feature_ids:', sorted(ids))
"
Top-level keys: ['type', 'name', 'crs', 'dropped_count', 'features'] dropped_count: 20 Feature count: 80 All checks passed! Kept feature_ids: [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]
0:43
Let me verify which features were dropped: - Features 1-5: geometry is null (no drawable geometry) - Features 6-10: geometry is LineString but coordinates is empty array (no drawable points) - Features 11-15: geometry is null AND waterway_type is null - Features 16-20: have proper LineString geometry but waterway_type is null That's: - 1-5: 5 features (null geometry, various types) - 6-10: 5 features (empty LineString, various types) - 11-15: 5 features (null geometry, null type) - 16-20: 5 features (valid geometry but null type) Total dropped: 20. That matches. Kept: features 21-100 = 80 features. All are LineString with non-empty coordinates and a non-null waterway_type. The output looks correct!
0:43