[Python-ideas] Fwd: Define a method or function attribute outside of a class with the dot operator

Steven D'Aprano steve at pearwood.info
Fri Feb 10 10:25:07 EST 2017

On Sat, Feb 11, 2017 at 01:25:40AM +1100, Chris Angelico wrote:

> For what it's worth, my answers would be:
> __name__ would be the textual representation of exactly what you typed
> between "def" and the open parenthesis. __qualname__ would be built
> the exact same way it currently is, based on that __name__.

If I'm reading this right, you want this behaviour:

class Spam:

def Spam.func(self): pass

assert 'Spam.func' not in Spam.__dict__
assert 'func' in Spam.__dict__

assert Spam.func.__name__ == 'Spam.func'
assert Spam.func.__qualname__ == 'Spam.Spam.func'

If that's the case, I can only ask... what advantage do you see from 
this? Because I can see plenty of opportunity for confusion, and no 

For what its worth, Lua already has this feature:


    Lib = {}
    function Lib.foo (x,y)
      return x + y

If we define that function foo inside the Lib table, and then cause an 
error, the Lua interpreter tells us the function name:

> Lib.foo('a', 1)
stdin:2: attempt to perform arithmetic on local 'x' (a string value)
stack traceback:
        stdin:2: in function 'foo'
        stdin:1: in main chunk
        [C]: in ?


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