singletons.novalue

Pythonic FP - Collection of singleton classes

class pythonic_fp.singletons.novalue.NoValue

Singleton class representing a missing value.

Similar to None but

• while None represents “returned no values”

• NoValue() represents the absence of a value

Usage:

• import NoValue from pythonic-fp.singletons and then

  • either use NoValue() directly

  • or define _noValue: Final[NoValue] = NoValue() don’t export it

• compare using is and is not

  • not == or !=

  • None means returned no values, so None == None makes sense

  • if one or both values are missing, then what is there to compare?