[pylint] why pylint wants only capitals identifiers?

[Giacomo Boffi]

i have this code

def example(a):
    return lambda b: a+b+1

fun = example(10)
k_1 = fun(7)
...

and pylint tells me

[...]
C:  4: Invalid name "fun" (should match (([A-Z_][A-Z0-9_]*)|(__.*__))$)
C:  5: Invalid name "k_1" (should match (([A-Z_][A-Z0-9_]*)|(__.*__))$)
[...]

afaict, [A-Z_][A-Z0-9_]* identifiers should be used for constants, and
i don't think of fun or k_1 as constants... what's going on?

tia,
                                                                g
-- 
la lenza penzola
                                           -- PMF, in IHC