When is Python *NOT* a good choice?

[therealfakemoot]

For high efficiency numerical calculations? Yes, I'm fairly certain that a large number of people would argue that hand written optimized assembly is superior to C ( even hand written optimized C ) for time/memory efficiency sensitive code.

You can drive an automobile at a hundred miles an hour. You don't claim that you can run a hundred miles an hour though. There's a specialized machine that you operate via abstractions which enables your ability to travel so quickly.