[Elrac]

Looking at your wish for exploratory evaluations in for-comprehensions, I was reminded of how Clojure does this. I found it quite elegant.

The inside of the for-braces allow for keyword-based sub-clauses: There's

- ":when" which will suppress output for elements not matching a filter expression,

- ":while" which will stop when elements stop matching a filter, and

- ":let" which will let you bind some new values in mid-loop.

I rarely need these features, but when I do I find them really really helpful. Maybe someday someone will consider doing something similar in Python.