pylint #76912 False positive No value passed for parameter * in function call for instance.lambda [open]

pylint treat lamba at class level different from a function in python, they are the same, consider this code:

""" Test lambda in a class """
import pprint


class Test:
  """ lambda needs Test instance as first argument """
  lam = lambda self, icon: pprint.pprint([self, icon])

  def test(self):
      """ this works at least in python 2.4 through 2.7 """
      self.lam("an icon")

if __name__ == "__main__":
  Test().test()

In python (tested 2.4~2.7), Test().test and Test().lam are bound methods and thus Test().test() and Test().lam("anicon") are valid; while Test.test() and Test.lam() are invalid (need instance of Test as first argument).

Pylint doesn't seem to know this w.r.t. lambdas.

It seems Pylint think that lam = at class level is just a member variable, that is treats lam = lambda: ... same as if it was lam = 123.