正则表达式找到特定单词后的所有单词？

Question

I have a string like below:

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

I have to find the words after particular word.

I want to extract the words after the word "Subject" in above example.

The output should be like below:

Subject: -Figures/Nautical and beach.

I tried below regex:

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

But there is not fixed number of words after subject keyword to specify so I can't specify exact number of words.

How do I stop at "peroid" or space.There is no specific stopping criterion.

Answer 1

Your (?<=subject)(.{30}(?:\\s|.)) regex asserts the position after subject . then grabs 30 characters other than a linebreak symbol and then matches either a whitespace or any character but a linebreak symbol. This does not really fit your requirements as the substring can be of any length.

You may use alternation based regex with a capturing group:

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

See the regex demo

Details :

• subject: - literal subject: string
• \\s* - 0+ whitespaces
• ([^.]+|\\S+) - Group 1 capturing 1 or more non-period symbols or 1+ non-whitespace symbols

Note : the order of the alternatives matters here since [^.]+ matches spaces, and \\S+ does not. If the substring after \\s* starts with a dot, the \\S+ will match that substring up to a whitespace.

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: 

Answer 2

Try:

re.compile('Subject: [^*]+')

Demo

Answer 3

Regex:

(Subject:.+)\*\*

Match Subject and content after that till '**'

Code:

str = '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'
import re

a = re.search(r'(Subject:.+)\*\*',str)
print(a.group(1))