Comment by VWWHFSfQ | Hacker News Reader

Comment by VWWHFSfQ | Hacker News Reader

There are bugs in this code and I'm glad that I'm not the only one that has done it!

    graph = {
        key: {
            p
            for p in inspect.signature(method).parameters.keys()
            if p != "self" and not p.startswith("_")
        }
        for key, method in cls._registry.items()
    }

The first parameter to a bound method does not have to be called `self`. It's conventional, but not required. Is there a better way in the inspect module to filter these parameters? This comes up more often with classmethods where the naming convention `cls` is most common but I see `klass` somewhat frequently as well.

This got me thinking and I'm not even seeing the `self` being returned in the list of parameters on Python 3.8.5:

   >>> class Test:
   ...     def test(self, a, b, c=5):
   ...         return a + b + c
   ...
   >>> t = Test()
   >>> inspect.signature(t.test).parameters
   mappingproxy(OrderedDict([('a', <Parameter "a">), ('b', <Parameter "b">), ('c', <Parameter "c=5">)]))

That's because ``t.test`` returns a MethodType instance rather than a FunctionType instance, which is invoked without the self.

Ah, you're absolutely correct!

  In [4]: class Test:
     ...:     def test(self, a, b, c=5):
     ...:         return a + b + c
     ...:

  In [5]: inspect.signature(Test.test).parameters
  Out[5]:
  mappingproxy({'self': <Parameter "self">,
              'a': <Parameter "a">,
              'b': <Parameter "b">,
              'c': <Parameter "c=5">})

Then, any idea how you would address the GP's original point? How should "self" be detected if it can be called something else?

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