str对象没有属性选择

Question

出什么问题了？我该怎么办？我想制作一个网络爬网工具。 我正在使用BeautifulSoup接电话。

def get_page(url):
    try:
        import requests
        import bs4
        import lxml
        res = requests.get(url)
        soup = bs4.BeautifulSoup(res.content, "lxml")
        return soup
    except:
        return ""


def get_all_target(page):
    list = []


for elem in get_page(page).select("a"):
    list.append(elem.get("href"))
return list


def union(p, q):
    for e in q:
        if e not in p:
            p.append(e)


def crawl_web(seed):
    tocrawl = [seed]


crawled = []
while tocrawl:
    page = tocrawl.pop()
    if page not in crawled:
        union(tocrawl, get_all_target(get_page(page)))
        crawled.append(page)
return crawled

这些是我得到的错误：

File"<stdin>", line 1, in <module>
File "<stdin>", line 9, in crawl_web
File "<stdin>", line 3, in get_all_target
AttributeError: 'str' object has no attribute 'select'

在BeautifulSoup中使用“选择”方法有什么错误吗？