使用Python 3进行Webscrapping

Question

在抓取网站后，我已检索到所有html链接。将它们设置为set（）后，要删除所有重复项，我仍在检索某些值。如何删除“＃”，“＃content”，“＃uscb-nav-skip-header”的值，'/'，无，来自链接集。

from bs4 import BeautifulSoup
import urllib
import re

#Gets the html code for scrapping
r = urllib.request.urlopen('https://www.census.gov/programs-surveys/popest.html').read()

#Creates a beautifulsoup object to run
soup = BeautifulSoup(r, 'html.parser')

#Set removes duplicates
lst2 = set()
for link in soup.find_all('a'):
    lst2.add(link.get('href'))
lst2

{'#',
 '#content',
 '#uscb-nav-skip-header',
 '/',
 '/data/tables/time-series/demo/popest/pre-1980-county.html',
 '/data/tables/time-series/demo/popest/pre-1980-national.html',
 '/data/tables/time-series/demo/popest/pre-1980-state.html',
 '/en.html',
 '/library/publications/2010/demo/p25-1138.html',
 '/library/publications/2010/demo/p25-1139.html',
 '/library/publications/2015/demo/p25-1142.html',
 '/programs-surveys/popest/data.html',
 '/programs-surveys/popest/data/tables.html',
 '/programs-surveys/popest/geographies.html',
 '/programs-surveys/popest/guidance-geographies.html',
 None,
 'https://twitter.com/uscensusbureau',
 ...}

Answer 1

尝试以下操作：

Answer 2

Answer 3

如果您特别想排除'/'（尽管它是有效的URL），则只需在末尾写lst2.discard('/')。由于lst2是一个集合，因此如果存在则将其删除，否则将不执行任何操作。

Answer 4

Answer 5