Matching characters after a certain word and stop matching before this same word

Question

I would like a regex to match all characters after a certain word appear, and stop matching after if this same word appears (or if the expression ends). For example if I want to match every character after "by" or "per" and stop when "by" or "per" appears again:

• Order my clothes by color and by size => ['color and', 'size']
• You much do you spend per week and per category? => ['week and', 'category?']

So far, I have done the following:

(by|per)\s(\w+)

But only gives me one word

Answer 1

You may use

\b(by|per)\s+(.*?)(?=\s*(?:\b(?:by|per)\b|$))

See the regex demo

Details

• \\b - a word boundary
• (by|per) - Group 1: by or per words
• \\s+ - 1+ whitespaces
• (.*?) - Group 2: any zero or more chars other than line break chars, as few as possible up to the first occurrence of...
• (?=\\s*(?:\\b(?:by|per)\\b|$)) - a sequence of
  • \\s* - 0+ whitespaces
  • (?:\\b(?:by|per)\\b|$) - either of
    • \\b(?:by|per)\\b - by or per whole words
    • | - or
    • $ - end of string.