re = /(?<=by )((\w+) (\w+))(?:,\s*)?((\w+) (\w+))?(?:\s*(?<=and ))((\w+) (\w+))/mi
str = 'By Person One, Person Two and Person Three
By Person One, Person Two
By Person One
By Person Two and Person Three
'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html