lista = [['1', 0.0, 1.8], ['1', 3.0, 2.0], ['1', 5.0, 1.5], ['1', 6.0, 1.5], ['1', 9.0, 3.0], ['2', 0.0, 1.8], ['2', 1.0, 1.5], ['2', 2.0, 1.5], ['2', 3.0, 2.0], ['2', 8.0, 2.1], ['3', 0.0, 1.8], ['3', 1.0, 2.0], ['3', 4.0, 1.5], ['3', 8.0, 1.5], ['3', 9.0, 1.5], ['4', 0.0, 1.8], ['4', 1.0, 1.5], ['4', 2.0, 2.0], ['4', 3.0, 2.0], ['4', 4.0, 2.0]]
 
agrupadas = {}
for elem in lista:
    fila = elem[0]
    if fila in agrupadas:
        agrupadas[fila][1].append(elem[1])
        agrupadas[fila][2].append(elem[2])
    else:
        agrupadas[fila] = [fila, [elem[1]], [elem[2]]]
 
resultado = []
for item in agrupadas.values():
    resultado.append([item[0], sum(item[1])/len(item[1]), sum(item[2])/len(item[2])])
 
print(resultado)
 

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