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Python Object-Oriented Python (retired) Inheritance __str__

Posted by Hunter Kiely
Hunter Kiely
2,768 Points

Help understanding a specific argument given to the format function

The str method (~1:40) returns a string using the .format function. 

def __init__(self, **kwargs):
    self.hit_points = random.randint(self.min_hit_points, self.max_hit_points)
    self.experience = random.randint(self.min_experience, self.max_experience)
    self.color =  random.choice(COLORS)

for key, value in kwargs.items():
    setattr(self, key, value)

def __str__(self):
    return('{} {}, HP: {}, XP: {}'.format(self.color.title(),      #here

How is the str method able to access the color variable, when the self.color variable is defined in the init? I believe the answer I am looking for is an explanation on self with pointers.

1 Answer

Tom Sager
Tom Sager
18,987 Points
Tom Sager
Tom Sager
18,987 Points

str is an instance method, which can only be called after init has been called. Init creates an instance. References to self within an object definition point to whatever instance was used to call that method.

So init creates an instance with a particular color, and str returns variables from that instance (such as color).

from monster import Dragon  # creates the Dragon class from the monster class
draco = Dragon()   # calls init, which creates a new instance named draco (with a color)
print(draco)       # calls str; draco is the instance, so 'self' points to draco