Some people use C++ for speed and Python for rapid prototyping and glue-logic, but combining the two can be tricky. Nim replaces both. It's not quite as fast as C++ (unless you are very careful about memory) and not quite as agile as Python (imo), but when you need both, Nim is great.
Note that Nim iterators correspond to Python generators, an amazingly useful feature. Combined with templates, it swamps C++ in agility. And macros take it to a whole nother level.
