python - 正则表达式查找特定单词之后的所有单词？

Question

我有一个如下所示的字符串:

Features:  -Includes hanging accessories.  -Artist: William-Adolphe Bouguereau.  -Made with 100pct cotton canvas.  -100pct Anti-shrink pine wood bars and Epson anti-fade ultra chrome inks.  -100pct Hand-made and inspected in the U.S.A.  -Orientation: Horizontal.  **Subject: -Figures/Nautical and beach.**  Gender: -Unisex/Both.  Size: -Mini 17'' and under/Small 18''-24''/Medium 25''-32''/Large 33''-40''/Oversized 41'' and above.  Style: -Fine art.  Color: -Blue.  Country of Manufacture: -United States.  Product Type: -Print of painting.  Region: -Europe.  Primary Art Material: -Canvas. Dimensions:  -8'' H x 12'' W x 0.75'' D: 0.72 lb.  -12'' H x 18'' W x 0.75'' D: 1.14 lbs.  -12'' H x 18'' W x 1.5'' D: 2.45 lbs.  -18'' H x 26'' W x 0.75'' D: 1.44 lbs.  Paintings Prints Tori White Wildon Photography Photos Posters Abstract Black D cor Designs Framed Hazelwood Hokku Home Landscape Oil Accent 075 12 15 18 26 40 60 8 D H W x 1 1017 1824 2532 holidays, christmas gift gifts for girls boys

我必须找到特定单词之后的单词。

我想提取上面示例中“Subject”之后的单词。

输出应如下所示:

Subject: -Figures/Nautical and beach.

我尝试了下面的正则表达式:

re.compile('(?<=subject)(.{30}(?:\s|.))',re.I)

但是主题关键字后没有固定的字数可供指定，因此我无法指定确切的字数。

如何在“周期”或空格处停止。没有具体的停止标准。

Answer 1

您的(?<=subject)(.{30}(?:\s|.))正则表达式断言 subject 之后的位置。然后抓取除换行符之外的 30 个字符，然后匹配空格或除换行符之外的任何字符。这并不真正符合您的要求，因为子字符串可以是任意长度。

您可以将基于交替的正则表达式与捕获组一起使用:

subject:\s*([^.]+|\S+)

请参阅regex demo

详细信息:

• subject: - 文字subject:字符串
• \s* - 0+ 空格
• ([^.]+|\S+) - 第 1 组捕获 1 个或多个非句号符号或 1 个以上非空白符号

注意:自 [^.]+ 起，替代项的顺序很重要匹配空格，并且 \S+才不是。如果 \s* 之后的子串以点开头，\S+将该子字符串匹配到空格。

Python demo :

import re
p = re.compile(r'subject:\s*([^.]+|\S+)', re.IGNORECASE)
s = "Features:  -Includes hanging accessories.  -Artist: William-Adolphe Bouguereau.  -Made with 100pct cotton canvas.  -100pct Anti-shrink pine wood bars and Epson anti-fade ultra chrome inks.  -100pct Hand-made and inspected in the U.S.A.  -Orientation: Horizontal.  **Subject: -Figures/Nautical and beach.**  Gender: -Unisex/Both.  Size: -Mini 17'' and under/Small 18''-24''/Medium 25''-32''/Large 33''-40''/Oversized 41'' and above.  Style: -Fine art.  Color: -Blue.  Country of Manufacture: -United States.  Product Type: -Print of painting.  Region: -Europe.  Primary Art Material: -Canvas. Dimensions:  -8'' H x 12'' W x 0.75'' D: 0.72 lb.  -12'' H x 18'' W x 0.75'' D: 1.14 lbs.  -12'' H x 18'' W x 1.5'' D: 2.45 lbs.  -18'' H x 26'' W x 0.75'' D: 1.44 lbs.  Paintings Prints Tori White Wildon Photography Photos Posters Abstract Black D cor Designs Framed Hazelwood Hokku Home Landscape Oil Accent 075 12 15 18 26 40 60 8 D H W x 1 1017 1824 2532 holidays, christmas gift gifts for girls boys"
m = p.search(s)
if m:
    print(m.group())    # this includes Subject: 
    print(m.group(1))   # this does not include Subject: