Wyrażenie regularne: dopasuj wszystko po konkretnym słowie
re.search(r'(?<=test :)[^.\s]*',text)
Xenophobic Xenomorph
re.search(r'(?<=test :)[^.\s]*',text)test = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQAB'
var regex = /.*?base64(.*?)/g;
var match = regex.exec(test);
console.log(match[1]);