Итерация строк двух файлов для парсинга Юла

inputfile = "D:/ula_categor.txt"
myfile = open(inputfile, mode = "r", encoding = "utf8")
 
inputfile2 = "D:/goroda.txt"
myfile2 = open(inputfile2, mode = "r", encoding = "utf8")
 
outputfile = "D:/gorodaUnion.txt"
myfile3 = open(outputfile, mode = "w", encoding = "utf8")
 
for line in myfile:
    for line1 in myfile2:
        text = line.replace("moskva", line1)
        myfile3.write(text)
 
myfile.close()
myfile2.close()
myfile3.close()

inputfile = "C:/ula_categor.txt"
myfile = open(inputfile, mode = "r", encoding = "utf8")
 
inputfile2 = "C:/goroda.txt"
myfile2 = open(inputfile2, mode = "r", encoding = "utf8")
 
outputfile = "C:/Intel/gorodaUnion.txt"
myfile3 = open(outputfile, mode = "w", encoding = "utf8")
 
 
town = []
with open('C:/goroda.txt') as f:
    town = f.read().splitlines()
 
for line in myfile:#перебор строк файла с категориями
    for i in range(3623): #3623-длина списка городов(итерация)
        out = line.replace("moskva", town[i])#замена в строке moskva городом из списка
        print(out)
        myfile3.write(out)
 
 
 
myfile.close()
myfile2.close()
myfile3.close()