Maybe you could consider a pre-commit hook which blocks /^\s* \t/ on * .py? Or if nothing else it's simple enough to grep/ack for.
I'd also recommend making indentation whitespace visible if your editor supports it - it is syntax after all. I have vim configured to colour leading spaces green, leading tabs as blue, and tabs following anything other than a tab highlighted red. Making inconsistent indentation ugly is quite effective, though sadly ineffective on other people.
I'd also recommend making indentation whitespace visible if your editor supports it - it is syntax after all. I have vim configured to colour leading spaces green, leading tabs as blue, and tabs following anything other than a tab highlighted red. Making inconsistent indentation ugly is quite effective, though sadly ineffective on other people.