Python

Question

from bs4 import BeautifulSoup
import requests
 
url = "https://www.wikipedia.com/wiki/computer"

response = requests.get(url)
data = response.text
soup = BeautifulSoup(data, "lxml")
results = soup.find_all("a")

for results in results:
    if results.get("href") [:5] == "https":
        print(results.get("href"))

此代码returns出现以下错误：

TypeError: 'NoneType' object is not subscriptable

我试过将 [:5] 放在 () 中，这会停止错误但不会输出超链接。我哪里做错了？

Answer 1

始终检查函数调用的 return 值。

all_results = soup.find_all("a")

for results in all_results:
    result = results.get("href")
    if result is None:
        pass # put a breakpoint here to see all the results which do not contain a "href" tag
    elif result.startswith("https"):
        print(result)

Python - 'NoneType' 对象不可订阅？

Python - 'NoneType' object is not subscriptable?

slice

nonetype