Fails to execute due to mixed space/tab indentation problems.

[shaunharker]

There are a number of instances of the code involving the following text

	    elif isinstance(value, datetime):
		result[attr] = str(value.date())
            else:
                result[attr] = value

where the indentation has both spaces and tabs. (Spaces-only are to be preferred, of course). Unfortunately this fails to parse on my system (macOS with Python 3.7). Since the same code snippet is replicated many times it cannot be fixed just in one place so it might be worth considering https://en.wikipedia.org/wiki/Don%27t_repeat_yourself to shorten the code and make it easier to maintain.