Feature or enhancement

Proposal:

With floating point data, thefloat('NaN') special value is commonly used as a placeholder for missing values. We providemath.isnan to support stripping out those values prior to sorting or summation:

>>>frommathimportisnan>>>fromitertoolsimportfilterfalse>>>data= [3.3,float('nan'),1.1,2.2]>>>sorted(filterfalse(isnan,data))[1.1,2.2,3.3]

For non-float data, theNone special value is commonly used as a placeholder for missing values. I propose a new function in the operator module analogous tomath.isnan():

>>> data= ['c',None,'a','b']>>>sorted(filterfalse(is_none, data))['a', 'b', 'c']

This helps fulfill a primary use case for the operator module which is to support functional programming withmap(),filter(), etc.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-115808: Addis_none andis_not_none operators #115814