Understanding what lisp-ers mean by 'repl-driven development' -- and why a python or node repl isn't it -- is really hard for people who don't get this, and haven't used it in practice.
It's not even only about the syntax. The Python environment, as far as I understand (and please correct me if I'm wrong), does not support re-definitions very well. Some things can be re-defined, but some cannot. So that's a problem in itself which makes REPL-driven development not very useful in Python.
Not only can you redefine classes, you can change the class an object belongs to. Just point `obj.__class__` at something else, or change `cls.__bases__` to reorganize the class's inheritance hierarchy.
It's not even only about the syntax. The Python environment, as far as I understand (and please correct me if I'm wrong), does not support re-definitions very well. Some things can be re-defined, but some cannot. So that's a problem in itself which makes REPL-driven development not very useful in Python.