Showing dynamic Class/Object possibilites using object.__dict__ in Python 3.6+

point1.py

import math

# basic point class
class Point(object):

    def __init__(self, x, y):
        self.x = x
        self.y = y

    def distance(self, other_point):
        return math.hypot(self.x - other_point.x, self.y - other_point.y)

def run():
    p1 = Point(1, 2)
    p2 = Point(2, 3)

    print(f'distance: {p1.distance(p2):.5f}')

if __name__ == '__main__':
    run()

point2.py

import math

# added __repr__ printing self.__dict__
class Point(object):

    def __init__(self, x, y):
        self.x = x
        self.y = y

    def distance(self, other_point):
        return math.hypot(self.x - other_point.x, self.y - other_point.y)

    def __repr__(self): return str(self.__dict__)  # new

def run():
    p1 = Point(1, 2)
    p2 = Point(2, 3)
    print(f'p1:{p1}  p2:{p2}')  # new

    print(f'distance: {p1.distance(p2):.5f}')

if __name__ == '__main__':
    run()

point3.py

import math

class Point(object):

    defaults = {'x': 0, 'y': 0}  # new

    def __init__(self):
        self.__dict__.update(Point.defaults)  # new body

    def distance(self, other_point):
        return math.hypot(self.x - other_point.x, self.y - other_point.y)

    def __repr__(self): return str(self.__dict__)

def run():  # modified
    p1 = Point()
    print(f'p1:{p1}')


if __name__ == '__main__':
    run()

point4.py

import math

# created template and class method to update it
class Point(object):

    defaults = {'x': 0, 'y': 0}  # new

    @classmethod
    def set_defaults(cls, **kwargs):  # new method
        Point.defaults.update(kwargs)

    def __init__(self):
        self.__dict__.update(Point.defaults)  # new body

    def distance(self, other_point):
        return math.hypot(self.x - other_point.x, self.y - other_point.y)

    def __repr__(self): return str(self.__dict__)

def run():  # modified
    p1 = Point()
    print(f'p1:{p1}')
    Point.set_defaults(x=99)

    p2 = Point()
    print(f'p2:{p2}')

    # surprise
    Point.set_defaults(z=0)
    p3 = Point()
    print(f'p3:{p3}')
    p3.z = 42
    print(f'p3:{p3}')

if __name__ == '__main__':
    run()

point_final.py

import math

# add dynamic object attributes
class Point(object):

    defaults = {'x': 0, 'y': 0}

    @classmethod
    def set_defaults(cls, **kwargs):
        Point.defaults.update(kwargs)

    def __init__(self, *args, **kwargs):
        self.__dict__.update(Point.defaults)

        keys = list(Point.defaults.keys())
        for i, v in enumerate(args):  # copy args to __dict__ in order
            self.__dict__[keys[i]] = v

        self.modify_attributes(**kwargs)

    def modify_attributes(self, **kwargs):
        self.__dict__.update(kwargs)  # new

    def distance(self, other_point):
        return math.hypot(self.x - other_point.x, self.y - other_point.y)

    def __repr__(self): return str(self.__dict__)

def run():  # modified
    p1 = Point(1, 2, z=99, label='p1')
    print(p1)
    p1.modify_attributes(z=88, color='green')
    print(p1)


if __name__ == '__main__':
    run()

PointV.txt

Lessons in dynamic attributes for a class using self.__dict__
  From python.org documents:

      object.__dict__ :
        A dictionary or other mapping object
        used to store an object’s (writable) attributes.

Learn to object.__dict__  for:

1. Setting defaults for the classes/object attributes
   Kind of like a dynamic template for your objects

2. Defining a flexible constructor can be called with attributes or
   allowed to be set to defaults

3. Adding new attributes to class to affect future object instances

4. Adding attributes to specific object dynamically after creation


*** this code relies on python version 3.6+ or 3.7+

*** This is just one way to do these things,
I don't claim they are the most pythonic way.

*** you should already know these concepts:
 @classmethod, *args, **kwargs, and dict update, enumerate