使用'/'大于小于Python？

Question

I recently got into code golfing and need to save as many characters as possible.

I remember seeing someone say to use if a/b: instead of if a<=b: . However, I looked through Python documentation and saw nothing of the sort.

I could be remembering this all wrong, but I'm pretty sure I've seen this operator used and recommended in multiple instances.

Does this operator exist? If so, how does it work?

Answer 1

That's just division. And, at least for integers a >= 0 and b > 0 , a/b is truthy if a>=b . Because, in that scenario, a/b is a strictly positive integer and bool() applied to a non-zero integer is True .

For zero and negative integer arguments, I am sure that you can work out the truthiness of a/b for yourself.

Answer 2

>>> 5/6
0
>>> bool(5/6)
False

>>> 6/5
1
>>> bool(6/5)
True

It's a result of the / operator in Python 2.7 doing integer division, then converting the result to a boolean.

If you do from __future__ import division , this won't work anymore because the / operator will do floating point division rather than integer division.

So the result will still be > 0 for x < y and will still evaluate to True.

>>> from __future__ import division

>>> 5/6
0.8333333333333334
>>> bool(5/6)
True

>>> 6/5
1.2
>>> bool(6/5)
True