Why is truth() faster than bool() in Python?

Uncommon to see such a linkbaitish title for a programming post. The reason truth() (from operator) is faster than bool() is that

* bool() takes one optional and named argument, and

* truth() takes one argument.

For those wondering what the hell truth() is, I think they're talking about this phenomenon:

  python -m timeit "if bool(1): x = 1"
  1000000 loops, best of 3: 0.187 usec per loop

  python -m timeit "if 1: x = 1"
  10000000 loops, best of 3: 0.0266 usec per loop

This article doesn't actually answer the question posed by the title, FYI.