This was an issue in Python 2, where for some dumb reason it allowed mixing tabs and spaces and equated tab to 8 spaces (I think). Python 3 doesn't have that issue.
Of course, if one was coding an exploit, one could still use python2. It is still commonly available due to a long tail of legacy scripts and in some cases (like a script I use routinely but didn't write) the difficulty of porting it to python3 (I've asked over a dozen pythonistas over the years, they kept running into same problems)
