python實作取txt檔案中檔案名稱的具體位置

b=[]
count = 1
all_count = 1
filename = "/media/zong.txt"
output_file='/media/d.txt'

country_list = []
with open(filename, "r") as ins: #打開檔案
    for line in ins: #循環檔案的每一行
        a = line[2:-5]
        b.append(a)
        b.sort()
        writer = open(output_file, 'w')
        writer.write('\n'.join('%s' %id for id in b))
        writer.close()