beautiful soup python中的find()和find_all()有什么区别？

Question

我正在做网页抓取，但我在 find() 和 find_all() 中陷入/困惑。

比如哪里使用find_all，哪里使用find()。

另外，我可以在哪里使用这种方法，例如在for 循环或ul li列表中？

这是我尝试过的代码

from bs4 import BeautifulSoup
import requests

urls = "https://www.flipkart.com/offers-list/latest-launches?screen=dynamic&pk=themeViews%3DAug19-Latest-launch-Phones%3ADTDealcard~widgetType%3DdealCard~contentType%3Dneo&wid=7.dealCard.OMU_5&otracker=hp_omu_Latest%2BLaunches_5&otracker1=hp_omu_WHITELISTED_neo%2Fmerchandising_Latest%2BLaunches_NA_wc_view-all_5"

source = requests.get(urls)

soup = BeautifulSoup(source.content, 'html.parser')

divs = soup.find_all('div', class_='MDGhAp')

names = divs.find_all('a')

full_name = names.find_all('div', class_='iUmrbN').text

print(full_name)

并得到这样的错误

  File "C:/Users/ASUS/Desktop/utube/sunil.py", line 9, in <module>
    names = divs.find_all('a')
  File "C:\Users\ASUS\AppData\Local\Programs\Python\Python38-32\lib\site-packages\bs4\element.py", line 1601, in __getattr__
    raise AttributeError(

AttributeError: ResultSet object has no attribute 'find_all'. You're probably treating a list of items like a single item. Did you call find_all() when you meant to call find()?

那么谁能解释我应该在哪里使用查找和查找全部？

Answer 1

通过这个例子也许更清楚：

from bs4 import BeautifulSoup
import re

html = """
<ul>
<li>First</li>
<li>Second</li>
<li>Third</li>
</ul>
"""   
soup = BeautifulSoup(html,'html.parser')

for n in soup.find('li'):
  # It Give you one element     
  print(n)

for n in soup.find_all('li'):    
  # It Give you all elements
  print(n)

结果 ：

First

<li>First</li>
<li>Second</li>
<li>Third</li>

欲了解更多信息，请阅读此https://www.crummy.com/software/BeautifulSoup/bs4/doc/#calling-a-tag-is-like-calling-find-all