Yes, I used IPython a lot.

What I meant by better interactive interface is that the language itself is designed with interactive use in mind.

For instance compare

  func(x$a, x$b)
  func(a, b, data=x)
  func(a=1, b=2)

with

  func(x['a'], x['b'])
  func('a', 'b', data=x)
  func([1, 2], ['a', 'b'])

The R versions are easier to type and read.

If the Python version is Pandas you could replace the brackets with dot notation. (x.a, x.b)

the last one is, of course, a result of the atrocious handling of the default arguments in Python :)