What is considered an "advanced" topic in Python?

[Laura Creighton]

If you are giving a talk about Decimal -- and trying to stamp out the
inappropriate use of floats you have to first inform people that
what they learned as 'decimals' as children was not floating point,
despite the fact that we write them the same way.

If I ever get the time machine, I am going back in time and demand that
floating point numbers be expressed as 12345:678 instead of 12345.678
because it would save so much trouble.  Never has the adage 'It's not
what you don't know, that bites you.  It's what you know that ain't so.'
been more apt.

I have done much better in speaking about this topic to a bunch of
incredulous people if you next explain that scientists really don't
care about accuracy in their calculations.  (This will surprise them).
Most scentific calculations have some real world measurement in them,
and for most real world measurements, if you are getting even 5 digits
of precision, you are doing really, really, well.  This means that
scientists are going to be throwing away all the extra digits they get
out a a floating point representation, so they don't have to care how
accurate they are.  As long as their results are good in the first 5,
it won't matter.  (Depending on time constraints, a review of
significant figures -- what they are and what they mean is good here.)

It is really hard to get the concept of Decimal across to people who
already have that concept in their mind, but think it is called Float.
You have to first teach them that they don't know anything about Float
and get them to reboot their brains before you can install this new
knowledge.  Otherwise their brains will just overwrite your new knowledge
with 'ah, just use a Float' as soon as you stop speaking.  Same day,
even.

Laura