assert lower <= upper

And apologies if this has been requested before.  My search turned up nothing.

On Saturday, July 30, 2016 at 5:57:53 PM UTC-4, Neil Girdhar wrote:
It's common to want to clip (or clamp) a number to a range.  This feature is commonly needed for both floating point numbers and integers:


There are a few approaches: 

* use a couple ternary operators (e.g. https://github.com/scipy/scipy/pull/5944/files  line 98, which generated a lot of discussion)
* use a min/max construction,
* call sorted on a list of the three numbers and pick out the first, or
* use numpy.clip. 

Am I right that there is no *obvious* way to do this?  If so, I suggest adding math.clip (or math.clamp) to the standard library that has the meaning:

def clip(number, lower, upper):
    return lower if number < lower else upper if number > upper else number

This would work for non-numeric types so long as the non-numeric types support comparison.  It might also be worth adding

assert lower < upper

to catch some bugs.