Python class creates attributes in order

Question

I am hoping to do some calculation using class methods and create a new attribute for each function (create_d and create_e). It doesn't feel very elegant because one has to run create_d before create_e. Is there a better way to organize them?

new_obj = TestClass(a, b, c)
new_obj.create_d(data)
new_obj.create_e(data)

class TestClass(object):

    def __init__(self, a, b, c):
        self._a = a
        self._b = b
        self._c = c

    def create_d(self, data):
        self._d = math(data, self._a, self._b)

    def create_e(self, data):
        self._e = more_math(data, self._d)

Answer 1

As a comment says, you can pass data as parameter

class TestClass(object):

    def __init__(self, a, b, c, data):
        self._a = a
        self._b = b
        self._c = c
        self._d = math(data, self._a, self._b)
        self._e = more_math(data, self._d)

Then to initialize:

new_obj = TestClass(a, b, c)

EDIT:

If you don't wanna carry self._d and self._e because their calculation is so expensive you can use properties as below:

@property
def create_d(self, data):
  return math(data, self._a, self._b)
    
@property
def create_(self, data):
  return more_math(data, self._d)

And then when you need the values just call the properties:

new_obj.create_d # return the calculation

Or if you're gonna use after just store it in a variable:

e = new_obj.create_e

You can check this out for more examples. Hope this can help you :)