Python becomes a platform

The recent announcement of clojure-py made some noise in the Clojure community, but not, as far as I can tell, in the Python community. For those who haven't heard of it before, clojure-py is an implementation of the Clojure language in Python, compiling Clojure code to bytecode for Python's virtual machine. It's still incomplete, but already usable if you can live with the subset of Clojure that has been implemented.

I think that this is an important event for the Python community, because it means that Python is no longer just a language, but is becoming a platform. One of the stated motivations of the clojure-py developers is to tap into the rich set of libraries that the Python ecosystem provides, in particular for scientific applications. Python is thus following the path that Java already went in the past: the Java virtual machine, initially designed only to support the Java language, became the target of many different language implementations which all provide interoperation with Java itself.

It will of course be interesting to see if more languages will follow once people realize it can be done. The prospect of speed through PyPy's JIT, another stated motivation for the clojure-py community, could also get more lanuage developers interested in Python as a platform.

Should Python programmers care about clojure-py? I'd say yes. Clojure is strong in two areas in which Python isn't. One of them is metaprogramming, a feature absent from Python which Clojure had from the start through its Lisp heritage. The other feature is persistent immutable data structures, for which clojure-py provides an implementation in Python. Immutable data structures make for more robust code, in particular but not exclusively for concurrent applications.