human
I am working on the file "Python_OO.ipynb".
The first task is:
Methods
So far this just looks like another way to store your data. It becomes more powerful when you write methods for your object. 
Methods can be thought of as functions associated with an object.
You can now access the attributes of the object within methods by calling self.&lt;attribute name&gt;.
Let's make a simple method for the SpaceRock object, which determines the size of the asteroid.
Can you write Python program for it?
 ... Can you provide a the Python program you requested?
assistant
#Here is the Python program you requested.

class SpaceRock(object):
    
    def __init__(self, name=None, ab_mag=None, albedo=None):
        self.name = name
        self.ab_mag = ab_mag
        self.albedo = albedo
        
    def diameter(self):
        result = (1329.0 / np.sqrt(self.albedo)) * (10 ** (-0.2 * self.ab_mag))
        return result * u.km