I would like to set up an abstraction where I would like to only allow the sub datatypes of Foo to be passed in parts of my application. All of these really are typed NamedTuples, as they carry no functionality. This leads me to have Foo inherit from typing.NamedTuple, and add no additional functionality to Foo. My issue is when instantiating subtypes of Foo, I am greeted with an error.
Consider the following snippet
from typing import NamedTuple
class Foo(NamedTuple):
pass
class Bar(Foo):
a: int
b: str
class Baz(Foo):
one_thing: float
another_thing: float
bar = Bar(4, "sdlfkjsdfkj")
print(bar)
The output of the snippet will be the following error...
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-20-b0f9b9293905> in <module>
15 another_thing: float
16
---> 17 bar = Bar(4, "sdlfkjsdfkj")
18 print(bar)
TypeError: __new__() takes 1 positional argument but 3 were given
However if I let Bar inherit directly from typing.NamedTuple then I am able to get the following snippet to function properly
class Bar(NamedTuple):
a: int
b: str
bar = Bar(4, "sdlfkjsdfkj")
print(bar)
>>> Bar(a=4, b='sdlfkjsdfkj')
Does this mean that for each data class definition (such as Bar or Baz) I have to inherit from typing.NamedTuple? Why can I not factor that out to a top level class?
Many Thanks in Advance!
