Admittedly it's not all that popular, but Tcl can do this with no problems at all. (By the way, Tcl also has an integrated event loop as well as a complete imp

Admittedly it's not all that popular, but Tcl can do this with no problems at all. (By the way, Tcl also has an integrated event loop as well as a complete implementation of coroutines, both of which Python only very recently got.)