python

#!/usr/bin/python
import os

def read_url_from_file():
    urls = []
    try:
        rp = open('urls.txt', 'r')
        urls = rp.readlines()
        rp.close()
    except:
        url = raw_input("file urls.txt not exists, please input a url >>>")
        if not url.lower().startswith('http://'):
            url = 'http://' + url
        urls.append(url)
    return urls

def save_result(urls, filename):
    wp = open(filename, 'w')
    wp.write('\n'.join(urls))#用'\n'连接字符串
    wp.close()

urls = read_url_from_file()
print urls
filename = 'abc'
save_result(urls, filename)