I have several classes that I don’t own. These classes provide methods to access internal information, rather than attributes or properties.

For example a class might look something like this:

class Foo:

  def __init__(self, a, b) -> None:
    self._a = a
    self._b = b

  def a(self): return self._a
  def b(self): return self._b
  def c(self): return self._a + self._b

I would like to be able to use match/case to do something like this:

foo_list = [
  Foo(1,0),
  Foo(0,1),
  Foo(1,2),
  Foo(3,3),
  Foo(3,2),
]

for foo in foo_list:
  match foo:
    case Foo(a=a, b=0):
      print(f'first a = {a}, b = {foo.b}')
    case Foo(a=0, b=b):
      print(f'second a = {foo.a}, b = {b}')
    case Foo(a=1, b=b):
      print(f'third a = {foo.a}, b = {b}')
    case Foo(a=a, b=3):
      print(f'forth a = {a}, b = {foo.b}')
    case Foo(a=a, b=b, c=5):
      print(f'fifth a = {a}, b = {b}, c = {foo.c}')`python

However this does not work since the case statements matching an object expect constructor-like syntax where the named arguments are attributes or properties not getter methods, which is what I have.

What is the Pythonic way to match/case statements with classes such as this?