正则表达式：第二次匹配

Question

I`d created a regex for matching nth occurence in the string:

^(?:[^-]*-){2}([^-].*)

However, testing it in the regex tool did not get 100% matching solution:

For example:

origin: ANIMAL - Animal Rage XL Pre-Workout Grape of Wrath - 151 Grams

expected: ANIMAL - Animal Rage XL Pre-Workout Grape of Wrath

tested: ANIMAL - Animal Rage XL Pre

origin: AST Sports Science - R-ALA 200 - 90 Capsules

expected: AST Sports Science - R-ALA 200

tested: AST Sports Science - R

I understand that in given above regex it is matches second occurrence of "-", and I`d created next regex:

^(?:[^-]*\s-\s){2}([^-].*)

But it is misses the examples above at all.

What I miss for the perfect regex work?

Thanks for help.

Answer 1

You could try the below.

>>> s = 'ANIMAL - Animal Rage XL Pre-Workout Grape of Wrath - 151 Grams'
>>> s1 = 'AST Sports Science - R-ALA 200 - 90 Capsules'
>>> re.search(r'^(?:.*? - .*?)(?= - )', s).group()
'ANIMAL - Animal Rage XL Pre-Workout Grape of Wrath'
>>> re.search(r'^(?:.*? - .*?)(?= - )', s1).group()
'AST Sports Science - R-ALA 200'

https://regex101.com/r/sJ9gM7/29

You could use re.sub function also.

>>> re.sub(r' - (?:(?! - ).)*$', '', s)
'ANIMAL - Animal Rage XL Pre-Workout Grape of Wrath'
>>> re.sub(r' - (?:(?! - ).)*$', '', s1)
'AST Sports Science - R-ALA 200'

This matches the last part of <space>hyphen<space> delimited string. Replacing the match with an empty string will give you the desired output.

Answer 2

It looks like you are looking for this regex: (?m)^(.*)(\\s+\\-\\s+(?!\\s\\-\\s).*)$

Sample code in Python:

str1 = 'ANIMAL - Animal Rage XL Pre-Workout Grape of Wrath - 151 Grams'
str2 = 'Anjolie Ayurveda - Rosemary Lavender and Neem Tulsi Soap Herbal Gift Box - CLEARANCE PRICED Nourish Your Skin & Awaken Your Senses'
print re.sub(r"(?m)^(.*)(\s+\-\s+(?!\s\-\s).*)$", "\g<1>", str1)
print re.sub(r"(?m)^(.*)(\s+\-\s+(?!\s\-\s).*)$", "\g<1>", str2)

Output:

ANIMAL - Animal Rage XL Pre-Workout Grape of Wrath                                                                                                                                                                                                     
Anjolie Ayurveda - Rosemary Lavender and Neem Tulsi Soap Herbal Gift Box