re = /(?:(^|,)(?i:[а-яё]()|[^,])*+(?!\2))+,?/
str = '42 year old, blonde, car, good green tree on field, правильное решение12, данных не больше 3, look what you\'ve done 4 times, pose 74, рисунок 12
привет, bobby, частота кадра 60fps, привет,'
subst = ''
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
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