Problema do Caixeiro Viajante

[JOAOBERNARD070 0]

Boa tarde podiam me ajudar neste codigo n me seleciona o menor de cada array 

 

distancias = [
    [0, 394,126, 272, 199, 63, 350, 494, 160, 117, 253, 234, 76, 188, 289, 149, 160, 87], #Aveiro
    [389, 0, 498, 541, 274, 338, 81, 147, 366, 272, 177, 182, 444, 205, 144, 521, 520, 425], # Beja
    [126, 505, 0, 217, 309, 174, 415, 604, 251, 234, 363, 344, 57, 298, 400, 54, 105, 178], # Braga
    [272, 543, 217, 0, 273, 289, 462, 726, 178, 356, 485, 362, 210, 420, 521, 280, 120, 200], # Bragança
    [274, 275, 307, 272, 0, 137, 189, 433, 97, 166, 224, 85, 257, 159, 244, 320, 243, 150], # Castelo Branco
    [63, 344, 171, 287, 138, 0, 244, 444, 167, 74, 203, 172, 122, 137, 239, 195, 187, 92], # Coimbra
    [344, 81, 414, 462, 192, 293, 0, 226, 286, 226, 132, 103, 364, 121, 99, 437, 475, 361], # Évora
    [390, 147, 599, 721, 432, 440, 226, 0, 524, 373, 278, 379, 549, 306, 245, 622, 621, 526], # Faro
    [163, 364, 254, 182, 95, 157, 283, 522, 0, 241, 313, 184, 204, 248, 349, 278, 152, 80], # Guarda
    [118, 273, 233, 355, 166, 73, 229, 386, 235, 0, 131, 171, 183, 80, 180, 256, 255, 160], # Leiria
    [254, 178, 364, 486, 225, 204, 134, 278, 317, 134, 0, 200, 314, 83, 49, 387, 386, 291], # Lisboa
    [233, 183, 341, 362, 85, 172, 103, 378, 187, 172, 198, 0, 292, 137, 194, 365, 358, 260], # Portalegre
    [74, 446, 55, 207, 259, 124, 365, 554, 201, 184, 313, 294, 0, 248, 350, 75, 95, 128], # Porto
    [186, 207, 295, 417, 156, 136, 123, 307, 248, 79, 80, 137, 245, 0, 116, 318, 317, 222], # Santarém
    [290, 145, 399, 521, 260, 239, 100, 244, 352, 182, 50, 194, 349, 118, 0, 422, 421, 326], # Setúbal
    [149, 521, 54, 280, 320, 195, 437, 622, 278, 256, 387, 365, 75, 318, 422, 0, 200, 200], # Viana do Castelo
    [160, 520, 105, 120, 243, 187, 475, 621, 152, 255, 386, 358, 95, 317, 421,200, 0, 98], # Vila Real
    [86, 431, 176, 198, 152, 93, 360, 531, 76, 160, 290, 260, 127, 224, 326, 200, 98, 0]] #Viseu

cidades = ["Aveiro", "Beja", "Braga", "Bragança", "Castelo Branco", "Coimbra", "Évora", "Faro", "Guarda", "Leiria", "Lisboa", "Portalegre", "Porto"]

a = []

tamanho = len(distancias)
distancia = 0
for i in range (tamanho):
    posicao = 0
    for u in range(tamanho):
        if(distancias[i][u] != 0):
            small = distancias[i][u]
            if(distancias[i][u] < small):
                small = distancias
                distancia+= small
                
print(small)

[M6 160]

Há uma forma mais simples, ordenas cada um dos arrays, vê o método sort(), e depois tiras a primeira posição, ou última, dependendo de como fizeste a ordenação.