贪心的正则表达式look[重复]

Question

我正在编写一个正则表达式来抓取“”之间的数据。我遇到的唯一问题是最后一个“ 正在被捕获。正则表达式

  line = '<DT><A HREF="https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html" ADD_DATE="1567455957">Clickjacking Defense · OWASP Cheat Sheet Series</A>'
  capture_regex = re.compile(r'(?<=HREF=").*?"',re.IGNORECASE)
  m = capture_regex.search(line)

< code>m.group()打印< code > https://cheatsheetseries . owasp . org/Cheat sheets/click jacking _ Defense _ Cheat _ sheet . html " 。如何编写不包含最后一个引号的正则表达式？

回答了我的问题。我添加了我在我的正则表达式中添加了所谓的非贪婪。capture_regex = 重新编译（r'（？




Answer 1

这将起作用：

import re

line = '<DT><A HREF="https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html" ADD_DATE="1567455957">Clickjacking Defense · OWASP Cheat Sheet Series</A>'

capture_regex = re.compile(r'(?<=HREF=")([^"]*)(?:")',re.IGNORECASE)
# capture_regex = re.compile(r'(?:HREF=")([^"]*)(?:")',re.IGNORECASE) this will work too
print(capture_regex.search(line).groups())
# print(capture_regex.findall(line))  # if your text contains more than one HREF

输出：

  ['https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html']

Answer 2

capture_regex = re.compile(r'(?<=HREF=").*?(?=")',re.IGNORECASE)

工作小提琴

编辑:调整了正则表达式，因为它太贪婪了。感谢@newdeveloper指出来！

Answer 3

也许，bs4中的＜code＞find_all＜/code＞可以正常工作：

from bs4 import BeautifulSoup

line = '<DT><A HREF="https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html" ADD_DATE="1567455957">Clickjacking Defense · OWASP Cheat Sheet Series</A>'
soup = BeautifulSoup(line, 'html.parser')

for l in soup.find_all('a', href=True):
    print(l['href'])

https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html

如果不是，也许，一些类似于

(?i)href="\s*([^\s"]*?)\s*"

使用re。findall＜/code＞可能在这里工作：

import re

expression = r'(?i)href="\s*([^\s"]*?)\s*"'

string = """
<DT><A HREF="https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html" ADD_DATE="1567455957">Clickjacking Defense · OWASP Cheat Sheet Series</A>
<DT><A HREF=" https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html " ADD_DATE="1567455957">Clickjacking Defense · OWASP Cheat Sheet Series</A>
"""

print(re.findall(expression, string))

['https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html', 'https://cheatsheetseries.owasp.org/cheatsheets/Clickjacking_Defense_Cheat_Sheet.html']

如果您希望浏览/简化/修改表达式，regex101.com 右上角的面板上进行了说明。如果您愿意，还可以在此链接中观看它与某些示例输入的匹配情况。