时间戳

首页 > 解决方案 > 如何过滤字符串列表中的关键字？

python - 如何过滤字符串列表中的关键字？

问题描述

我有一个字符串列表，这些字符串是我使用 BeautifulSoup 抓取的链接。我不知道如何只返回包含单词“The”的字符串。该解决方案可能使用正则表达式，但对我不起作用。

我试过了

for i in links_list:
     if re.match('^The', i) is not None:
        eps_only.append(i)

但我得到了像这样的错误

File "/opt/homebrew/Caskroom/miniconda/base/lib/python3.8/re.py", line 191, in match
    return _compile(pattern, flags).match(string)
TypeError: expected string or bytes-like object

该列表如下所示：

['index.html', 'seinfeld-scripts.html', 'episodes_oveview.html', 'seinfeld-characters.html', 'buy-seinfeld.html', 'http://addthis.com/bookmark.php?v=250&username=doctoroids', None, None, None, None, 'http://community.seinfeldscripts.com', 'buy-seinfeld.html', 'seinfeld-t-shirt.html', 'seinfeld-dvd.html', 'episodes_oveview.html', 'alpha.html', '    http://www.shareasale.com/r.cfm?u=439896&b=119192&m=16934&afftrack=seinfeldScriptsTop&urllink=search%2E80stees%2Ecom%2F%3Fcategory%3D80s%2BTV%26i%3D1%26theme%3DSeinfeld%26u1%3Dcategory%26u2%3Dtheme', ' TheSeinfeldChronicles.htm', ' TheStakeout.htm', ' TheRobbery.htm', ' MaleUnbonding.htm', ' TheStockTip.htm', ' TheExGirlfriend.htm', ' ThePonyRemark.htm', ' TheJacket.htm', ' ThePhoneMessage.htm', ' TheApartment.htm', ' TheStatue.htm', ' TheRevenge.htm', ' TheHeartAttack.htm', ' TheDeal.htm', ' TheBabyShower.htm', ' TheChineseRestaurant.htm', ' TheBusboy.htm', 'TheNote.html', ' TheTruth.htm', 'ThePen.html', ' TheDog.htm', ' TheLibrary.htm', ' TheParkingGarage.htm', 'TheCafe.html', ' TheTape.htm', 'TheNoseJob.html', 'TheStranded.html', ...]

更新：完整代码

import requests
import re
from bs4 import BeautifulSoup

##################
##--user agent--##
##################

user_agent_desktop = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) '\
    'AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 '\
    'Safari/537.36'

headers = {'User-Agent': user_agent_desktop}

#########################
##--fetching the page--##
#########################

URL = 'https://www.seinfeldscripts.com/seinfeld-scripts.html'
page = requests.get(URL, headers=headers)
soup = BeautifulSoup(page.content, 'html.parser')


############################################################
##--scraping the links to the scripts from the main page--##
############################################################

links_list = []
eps_only = []

for link in soup.find_all('a'):
    links_list.append(link.get('href'))

### sorting for links that contain 'the' ###

for i in filter(None, links_list):
    if re.match('^The', str(i)) is not None:
        eps_only.append(i)
        print(eps_only)

标签： pythonregexbeautifulsoup

解决方案

如果它作为参数传递， Pythonre.match将失败None——因此你得到的错误。

您的一些列表元素是None.

在将它们传递给re.match.

例如：

for i in links_list:
    if i is not None and re.match('^The', i) is not None:
        eps_only.append(i)

或者，您可以事先将它们过滤掉，如下所示：

links_list = [l for l in links_list if l is not None]

推荐阅读