import re
str = "text = [('Тестовый текст,)]"
x = re.findall("'([\w ]+)", str, re.UNICODE)
print(x[0])
aW1wb3J0IHJlCgpzdHIgPSAidGV4dCA9IFsoJ9Ci0LXRgdGC0L7QstGL0Lkg0YLQtdC60YHRgiwpXSIKeCA9IHJlLmZpbmRhbGwoIicoW1x3IF0rKSIsIHN0ciwgcmUuVU5JQ09ERSkKCnByaW50KHhbMF0p