import urllib.request as urllib2from bs4 import BeautifulSoup as bsfrom urllib.error import URLError, HTTPError, ContentTooShortErrora = []def download(url): print("download..."+url) try: html = urllib2.urlopen(url) except(URLError, HTTPError, ContentTooShortError) as e: print("download error:"+e.reason) html = None return htmldef parser_html(response): soup = bs(response, 'html.parser') return soup# 打印信息def out_information(soup): # 记录爬取了多少数据 indexSpan = 1 # 打印出title标签的内容 print(soup.title.string) # 将a标签的信息存储在a列表里 for link in soup.find_all('a'): a.append(str(indexSpan) + link.text) indexSpan += 1 # 打印出a列表的内容 print(a)if __name__ == "__main__": # 需要访问的url url = "https://www.baidu.com/" # 下载url response = download(url) # 解析网页 soup = parser_html(response) # 打印内容 out_information(soup)

这段代码尝试从指定的URL下载页面，然后使用BeautifulSoup来解析页面内容，最后打印出页面的title标签和所有链接（a标签）的文本内容。

不过，这段代码有几个问题：

1. `urllib2` 库的导入语句应该写成 `import urllib.request as urllib2`，否则会报错。
2. 在 `except` 语句中，`e.reason`应该改为`str(e)`或者`e.reason`改为`e.reason.strerror`，否则也会报错。
3. 在 `out_information` 函数中，变量 `a` 没有被初始化，需要在函数前面加上 `a = []` 进行初始化。

下面是修改后的代码：

import urllib.request as urllib2
from bs4 import BeautifulSoup as bs
from urllib.error import URLError, HTTPError, ContentTooShortError

a = []

def download(url):
    print("download..."+url)
    try:
        html = urllib2.urlopen(url)
    except (URLError, HTTPError, ContentTooShortError) as e:
        print("download error:" + str(e))
        html = None
    return html

def parser_html(response):
    soup = bs(response, 'html.parser')
    return soup

# 打印信息
def out_information(soup):
    # 记录爬取了多少数据
    indexSpan = 1
    # 打印出title标签的内容
    print(soup.title.string)
    # 将a标签的信息存储在a列表里
    for link in soup.find_all('a'):
        a.append(str(indexSpan) + link.text)
        indexSpan += 1
    # 打印出a列表的内容
    print(a)

if __name__ == "__main__":
    # 需要访问的url
    url = "https://www.baidu.com/"
    # 下载url
    response = download(url)
    # 解析网页
    soup = parser_html(response)
    # 打印内容
    out_information(soup)