tiagosamaha / dijkstra Goto Github PK

I am doing a math modeling to optimize the public traffic.l need a program to solve the problem of the shortest route.but I am freshman so that l can't understand the dijkstra.finally，I find your program.I think it is very good.thank you.
when i modify the program，usually program will meet the problem

for vertex in self.shortest_path():
File "C:\Users\Administrator\Downloads\dijkstra-master\dijkstra-master\dijkstra.py", line 51, in shortest_path
back = self.P[back]
KeyError: -1

what is the trouble？
in exemple_1.py ,my dict example is
{0: {1: 760, 59: 779, 33: 403}, 1: {0: 760, 2: 930, 60: 368}, 2: {1: 930, 3: 305, 61: 400, 129: 539}, 3: {136: 416, 2: 305, 4: 2000}, 4: {3: 2000, 5: 700, 150: 346}, 5: {161: 2411, 4: 700, 6: 922}, 6: {20: 651, 5: 922, 21: 274}, 7: {8: 437, 13: 359, 37: 561}, 8: {9: 490, 7: 437, 14: 364, 73: 557}, 9: {8: 490, 72: 561, 15: 364}, 10: {112: 956, 11: 495, 76: 919}, 11: {113: 849, 10: 495, 75: 923, 12: 317}, 12: {114: 789, 11: 317, 74: 913, 13: 586}, 13: {12: 586, 14: 431, 38: 666, 7: 359}, 14: {8: 364, 15: 485, 13: 431, 95: 395}, 15: {9: 364, 115: 186, 14: 485}, 16: {17: 515, 109: 420, 78: 790}, 17: {16: 515, 18: 899, 108: 586, 77: 639}, 18: {17: 899, 107: 619, 76: 389}, 19: {64: 456, 122: 757, 20: 478}, 20: {19: 478, 6: 651, 62: 483}, 21: {6: 274, 22: 519, 150: 1466}, 22: {23: 522, 21: 519, 62: 458, 55: 1025}, 23: {22: 522, 54: 1006, 63: 465}, 24: {25: 483, 31: 783, 57: 495}, 25: {24: 483, 32: 673, 26: 538, 58: 540}, 26: {40: 541, 25: 538, 33: 422}, 27: {28: 402, 146: 2329, 44: 1297}, 28: {27: 402, 29: 580, 45: 1129}, 29: {28: 580, 30: 347, 46: 908}, 30: {34: 1481, 29: 347, 31: 520}, 31: {24: 783, 32: 468, 30: 520}, 32: {25: 673, 31: 468, 33: 765}, 33: {0: 403, 32: 765, 26: 422}, 34: {56: 319, 30: 1481, 39: 521}, 35: {104: 394, 36: 428, 94: 463}, 36: {35: 428, 92: 235, 37: 507}, 37: {73: 433, 74: 645, 36: 507, 7: 561}, 38: {114: 546, 39: 1098, 13: 666, 95: 632}, 39: {96: 511, 34: 521, 125: 365, 38: 1098}, 40: {41: 519, 26: 541, 59: 534, 58: 527}, 41: {40: 519, 96: 1012, 42: 521, 149: 525}, 42: {41: 521, 154: 552, 43: 496, 148: 530}, 43: {153: 558, 42: 496, 147: 535}, 44: {27: 1297, 45: 515, 47: 323}, 45: {48: 327, 28: 1129, 44: 515, 46: 531}, 46: {49: 327, 29: 908, 45: 531}, 47: {48: 509, 145: 624, 44: 323}, 48: {49: 534, 45: 327, 142: 618, 47: 509}, 49: {48: 534, 56: 380, 46: 327}, 50: {51: 576, 147: 448, 118: 514}, 51: {152: 450, 50: 576, 52: 517, 119: 880}, 52: {120: 1217, 138: 451, 51: 517, 53: 343}, 53: {121: 1415, 52: 343, 54: 348, 127: 451}, 54: {23: 1006, 53: 348, 134: 450, 55: 517}, 55: {22: 1025, 54: 517, 151: 443}, 56: {49: 380, 34: 319, 125: 400, 57: 799}, 57: {24: 495, 56: 799, 58: 487, 96: 523}, 58: {40: 527, 25: 540, 160: 519, 57: 487}, 59: {0: 779, 40: 534, 60: 573, 149: 519}, 60: {1: 368, 59: 573, 156: 528, 61: 530}, 61: {60: 530, 2: 400, 140: 522}, 62: {20: 483, 22: 458, 63: 513}, 63: {122: 202, 62: 513, 23: 465}, 64: {65: 567, 19: 456, 97: 1345}, 65: {64: 567, 66: 514, 83: 431, 122: 454}, 66: {65: 514, 67: 341, 84: 435, 121: 497}, 67: {120: 539, 66: 341, 68: 441, 85: 432}, 68: {67: 441, 69: 459, 86: 456, 119: 626}, 69: {68: 459, 70: 477, 118: 779, 87: 510}, 70: {88: 507, 71: 364, 117: 858, 69: 477}, 71: {72: 181, 89: 512, 116: 946, 70: 364}, 72: {9: 561, 90: 511, 71: 181, 73: 535}, 73: {8: 557, 72: 535, 91: 511, 37: 433}, 74: {105: 912, 75: 319, 12: 913, 37: 645}, 75: {74: 319, 11: 923, 76: 495, 106: 951}, 76: {10: 919, 75: 495, 18: 389, 77: 923}, 77: {17: 639, 76: 923, 78: 549, 111: 1861}, 78: {16: 790, 77: 549, 110: 1882}, 79: {80: 330, 98: 565, 126: 324}, 80: {81: 317, 99: 551, 132: 380, 79: 330}, 81: {80: 317, 82: 241, 131: 373, 100: 559}, 82: {81: 241, 130: 402, 101: 552}, 83: {65: 431, 84: 547, 97: 872}, 84: {98: 877, 83: 547, 66: 435, 85: 328}, 85: {67: 432, 99: 875, 84: 328, 86: 319}, 86: {68: 456, 100: 872, 85: 319, 87: 317}, 87: {88: 485, 69: 510, 86: 317, 101: 874}, 88: {89: 352, 70: 507, 102: 759, 87: 485}, 89: {88: 352, 90: 194, 71: 512}, 90: {72: 511, 89: 194, 91: 533, 103: 631}, 91: {73: 511, 90: 533, 92: 194, 94: 528}, 92: {91: 194, 36: 235}, 93: {130: 532, 123: 807, 94: 1139}, 94: {35: 463, 91: 528, 93: 1139, 103: 500}, 95: {96: 1352, 115: 401, 14: 395, 38: 632}, 96: {41: 1012, 39: 511, 57: 523, 95: 1352}, 97: {64: 1345, 98: 577, 83: 872, 133: 925}, 98: {97: 577, 99: 329, 84: 877, 79: 565}, 99: {80: 551, 98: 329, 100: 318, 85: 875}, 100: {81: 559, 99: 318, 101: 247, 86: 872}, 101: {82: 552, 100: 247, 102: 356, 87: 874}, 102: {88: 759, 101: 356, 103: 382}, 103: {90: 631, 94: 500, 102: 382, 130: 1029}, 104: {105: 317, 123: 1346, 35: 394}, 105: {104: 317, 74: 912, 124: 1345, 106: 319}, 106: {105: 319, 75: 951, 107: 387, 141: 1333}, 107: {144: 1310, 18: 619, 108: 968, 106: 387}, 108: {17: 586, 107: 968, 109: 548}, 109: {16: 420, 108: 548}, 110: {78: 1882, 111: 517}, 111: {112: 1029, 77: 1861, 110: 517}, 112: {145: 1098, 10: 956, 111: 1029, 113: 406}, 113: {112: 406, 114: 327, 11: 849, 142: 1188}, 114: {113: 327, 12: 789, 125: 1112, 38: 546}, 115: {153: 495, 15: 186, 116: 373, 95: 401}, 116: {115: 373, 117: 380, 71: 946}, 117: {116: 380, 70: 858, 118: 426}, 118: {50: 514, 117: 426, 69: 779, 119: 682}, 119: {120: 616, 51: 880, 68: 626, 118: 682}, 120: {121: 360, 67: 539, 52: 1217, 119: 616}, 121: {120: 360, 66: 497, 122: 477, 53: 1415}, 122: {65: 454, 19: 757, 63: 202, 121: 477}, 123: {104: 1346, 124: 325, 93: 807}, 124: {105: 1345, 123: 325, 141: 244}, 125: {56: 400, 114: 1112, 142: 505, 39: 365}, 126: {132: 332, 133: 561, 79: 324}, 127: {128: 498, 138: 347, 53: 451, 134: 350}, 128: {127: 498, 129: 518, 139: 348, 135: 352}, 129: {128: 518, 136: 356, 2: 539, 140: 340}, 130: {103: 1029, 82: 402, 131: 430, 93: 532, 159: 353}, 131: {81: 373, 130: 430, 132: 327, 159: 365}, 132: {80: 380, 137: 651, 131: 327, 126: 332}, 133: {97: 925, 126: 561}, 134: {127: 350, 151: 524, 54: 450, 135: 500}, 135: {128: 352, 136: 517, 134: 500, 151: 723}, 136: {129: 356, 3: 416, 150: 1460, 135: 517}, 137: {132: 651, 158: 490, 159: 332}, 138: {152: 511, 139: 497, 52: 451, 127: 347}, 139: {128: 348, 138: 497, 155: 509, 140: 521}, 140: {129: 340, 139: 521, 156: 513, 61: 522}, 141: {144: 318, 106: 1333, 124: 244}, 142: {48: 618, 113: 1188, 125: 505, 145: 439}, 143: {144: 2106}, 144: {107: 1310, 141: 318, 143: 2106}, 145: {112: 1098, 142: 439, 47: 624}, 146: {27: 2329}, 147: {152: 578, 50: 448, 43: 535, 148: 500}, 148: {42: 530, 147: 500, 155: 581, 149: 520}, 149: {41: 525, 148: 520, 59: 519, 156: 585}, 150: {136: 1460, 4: 346, 21: 1466, 151: 522}, 151: {55: 443, 134: 524, 150: 522, 135: 723}, 152: {138: 511, 51: 450, 147: 578, 155: 497}, 153: {43: 558, 154: 494, 115: 495}, 154: {160: 522, 153: 494, 42: 552}, 155: {152: 497, 148: 581, 139: 509, 156: 520}, 156: {60: 528, 155: 520, 140: 513, 149: 585}, 157: {158: 976}, 158: {137: 490, 157: 976}, 159: {137: 332, 130: 353, 131: 365}, 160: {58: 519, 154: 522}, 161: {5: 2411}}

if you help me,l will think you very much