findall 错误 - NoneType' 对象没有属性 'findall'

Question

我不断收到错误消息“缺少 1 个必需的位置参数：'section_url'”

每次我尝试使用 findall 时都会收到此错误。

刚开始学习python，所以任何帮助都将不胜感激！

from bs4 import BeautifulSoup
import urllib3


def extract_data():

    BASE_URL = "http://www.chicagotribune.com/dining/ct-chicago-rooftops-patios-eat-drink-outdoors-near-me-story.html"

    http = urllib3.PoolManager()
    r = http.request('GET', 'http://www.chicagotribune.com/dining/ct-chicago-rooftops-patios-eat-drink-outdoors-near-me-story.html')
    soup = BeautifulSoup(r.data, 'html.parser')
    heading = soup.find("div", "strong")
    category_links = [BASE_URL + p.a['href'] for p in heading.findAll('p')]
    return category_links
    print(soup)


extract_data()

Answer 1

基于已接受答案的答案，我认为这就是您想要的

from bs4 import BeautifulSoup
import urllib3

def extract_data():

    BASE_URL = "http://www.chicagotribune.com/dining/ct-chicago-rooftops-patios-eat-drink-outdoors-near-me-story.html"

    http = urllib3.PoolManager()
    r = http.request('GET', 'http://www.chicagotribune.com/dining/ct-chicago-rooftops-patios-eat-drink-outdoors-near-me-story.html')
    soup = BeautifulSoup(r.data, 'html.parser')
    heading = soup.select('div strong')
    print(heading)
    category_links = [BASE_URL + p.a['href'] for p in [i for i, x in enumerate(heading) if x == "p"]]
    return category_links


print(extract_data())

Answer 2

通常，NoneType object has no attribute 类错误意味着上游函数返回了None，然后你没有检查它并尝试访问它的方法：

stuff = get_stuff()  # this returns None
stuff.do_stuff()  # this crashes

很可能，库找不到带有soup.find 的标题。尝试改用soup.select('div.strong')。

关于选择器的更多信息： https://www.crummy.com/software/BeautifulSoup/bs4/doc/#css-selectors

关于 NoneType 的更多信息： https://docs.python.org/3.6/library/constants.html#None