Выбрать данные о проводниках и упорядочить по убыванию плотности

with open('input.txt', encoding = 'utf-8') as f_in:
    
    f = f_in.read().replace(',', ' ')
    res = [[] for _ in range(3)]
    for line in f.splitlines():
        mat = line.split()
        res[int(mat[-1])].append(mat[:-1])
 
with open('conductor.txt', 'w', encoding = 'utf-8') as f_con,\
        open('semiconductor.txt', 'w', encoding = 'utf-8') as f_semicon,\
        open('insulator.txt', 'w', encoding = 'utf-8') as f_ins:
            
            for m in sorted(res[0], key=lambda x: -int(x[1])):
                print(*m, file=f_con)
                
            for m in sorted(res[1], key=lambda x: -int(x[1])):
                print(*m, file=f_semicon)
                
            for m in sorted(res[2], key=lambda x: -int(x[1])):
                print(*m, file=f_ins)

class ChemicalEl:
 
    def __init__(self, name_par="", density_par="100.12", conduction_par='0'):
        self.name = name_par
        self.density = float(density_par) if ',' not in density_par else float(density_par.replace(',', '.'))
        self.conduction = int(conduction_par)
 
    def __repr__(self):
        ret_ss = ''
        ret_ss += "\'" + self.name + "\'"
        ret_ss += " " + str(self.density)
        ret_ss += " " + str(self.conduction)
        return ret_ss
 
#ты дал файл в кодировке винды
with open(r"file.txt", encoding='cp1251') as fr:
    file_line_list = fr.readlines()
    conductors = []
    for line in file_line_list:
        line_parts = line.strip().split()
        if len(line_parts) == 3 and line_parts[2] == '1':
            conductors.append(ChemicalEl(line_parts[0], line_parts[1], line_parts[2]))
conductors.sort(key=lambda x: x.density, reverse=True)
print(conductors)