python 正则表达式非贪婪强制

Question

我在这里看到了一个关于非贪婪匹配的例子。

reg_string = "(.*?)>Title"
path = "<html><head><title>Title</title>"
match = re.match(reg_string, path)
if match:
   print match.group()

但是如果我想python大喊这个不匹配怎么办，因为第一个>之后就没有Title了。因为这场比赛：

"<html\><head><title>Title"

Answer 1

您可能想查看 BeautifulSoup Python 库以更直接地解析和处理 HTML:

https://www.crummy.com/software/BeautifulSoup/bs4/doc/

Answer 2

尝试reg_string = "([^>]*?)>Title"

Answer 3

据我了解，您想获取 Title 之前的所有内容；但是如果没有标题文本，那么它应该抱怨？

# Here we add a zero-to-many length match, delimited by `<` or end of line
# and capture it in a second group
reg_string = "(.*?)>(.*?)(<|$)"

path = "<html><head><title>Title</title>"

match = re.match(reg_string, path)
if match:
    if match.group(2) == "":
        throw Exception("No title content")
    else
        print match.group(1)
else:
    throw Exception("No match")

python 正则表达式非贪婪强制

python regex non-greedy forced

python

regex

non-greedy