Somewhat unrelated, but hte first concern that popped into my head is how the information contained ties to specific version of its subject? Like, the Python b

Somewhat unrelated, but hte first concern that popped into my head is how the information contained ties to specific version of its subject? Like, the Python book looks awesome but I have to use Python 2.7 day-to-day (don't ask). Are Python 2/3 stuff clearly marked?