It's not "just an example", it's the core of their argument. They say "Pythonic code uses a hash table-like data structure" - but that's completely wrong.
His other argument, about summing points, makes no sense either. He doesn't seem to have even profiled his "slow" point summing code or tried basic Python optimisations like using a list comprehension or generator to sum the points. And if that doesn't work well enough, and point summing is a critical part of your program, then you'd use a library like NumPy to handle that, rather than using raw python.
His other argument, about summing points, makes no sense either. He doesn't seem to have even profiled his "slow" point summing code or tried basic Python optimisations like using a list comprehension or generator to sum the points. And if that doesn't work well enough, and point summing is a critical part of your program, then you'd use a library like NumPy to handle that, rather than using raw python.