The underscore is to avoid conflicts with your own attributes named make, asdict, etc. So you could do:

  MyClass = namedtuple("MyClass", ["make", "asdict", "fields"])
  x = MyClass(make=10, asdict=11, fields=12)
  print(x.asdict)

The "underscore-to-avoid-naming-conflicts" approach is used elsewhere in the Python standard library, too, although another example isn't coming to me at the moment.