Sure, but I'm intimately familiar with the semantics of the programming languages I use. It takes the same effort to insure floating point versus integer computations in the Python REPL as it does when writing a Python program - which is not much.

I'd rather use my existing knowledge than learn how to interface with something that is probably not as robust or as well designed.

Instacalc.com might be closer to what you want.

I switched from Python to R as my calculator of choice for this reason.

I only recently discovered that there's a lot more to R than intuitive division of integers ;)

Yeah, but in Python you have other niceties, like dates.

Just the other day my pregnant wife asked me to calculate the aprox date she'll give birth (considering she has 17 weeks) ...

  from datetime import datetime, timedelta

  print str( datetime.now() + timedelta(weeks=40 - 17) )

Then use python 3.