Inner class function without self

Question

Peace, everyone! I'm using Python 3.6.3 and I find strange that such construction is possible:

class TestClass(object):
    def __init__(self):
        self.arg = "arg"

    def test():
        print("Hey test")

And using:

>>> TestClass.test()
"Hey test"

I know that in Python there are standard methods with self as parameter (don't know how to call them properly), static methods, class methods, abstract methods.

But what kind of method the test() is? Is it static method?

---

Edited:

Are there any useful usecases of such method of determining a function inside a class?

Answer 1

Let me explain with an example:

class TestClass(object):
  def __init__(self):
    self.arg = "arg"

  def test1():
    print("class method test1, Hey test")

  @classmethod
  def test2(cls):
    print("class method test2, Hey test")

  def test3(self):
    print("instance method test3, Hey test")

Look what happens when you call test1 with the class or with the instance:

First:

  TestClass.test1() #called from class
class method test1, Hey test
   TestClass().test1() #created an instance TestClass()
Traceback (most recent call last):
  File "python", line 1, in <module>
TypeError: test1() takes 0 positional arguments but 1 was given

that's because when you create an instance, the self parameter is used, but here, the method has not the self parameter, that's why it brakes.

next one!

   TestClass.test2()
class method test2, Hey test
   TestClass().test2()
class method test2, Hey test

That worked for instance and for class, why? well, as you can see test2(cls) take an argument, cls, here, I'm not using it, so, it's ok that it works.

bring me the next subject, muajaja

  TestClass().test3()
instance method test3, Hey test
   TestClass.test3()
Traceback (most recent call last):
  File "python", line 1, in <module>
TypeError: test3() missing 1 required positional argument: 'self'

That's easy to see, when you call it as class, you haven't provided the self parameter