Key Word(s): Class methods, Static methods, Instance methods, Dunder methods
Exercise 1¶
You have a Dog
class as shown below. The constructor sets up an instance of the class and specifies a list of dog colors and any special abilities. For example, a black lab color list would simply read ['black']
and the special abilities might be the string 'retrieving'
.
class Dog:
def __init__(self, breed, colors, special=None):
self.breed = breed
self.colors = colors
self.special = special
Suppose you're reading in some data about dog breeds and for some reason you want to create instances of each breed. You might do something like:
my_dog = Dog('lab', ['black'], 'retrieving')
vars(my_dog)
Of course, every time you need a lab
instance, you would need to remember these arguments. Instead, you could use classmethods
as a factory to generate objects that you want. This may be useful as a pre-processing step in some workflow.
Exercise Task¶
Include a classmethod
in the Dog
class for a beagle (or any other dog of your choosing). Here's how it should work:
my_dog = Dog.beagle()
print((my_dog)) # returns <__main__.Dog object at 0x10a4bc320>
print(vars(my_dog)) # returns {'breed': 'beagle', 'colors': ['black', 'white', 'brown'], 'special': 'hunting'}
Deliverables¶
The exercise solution should be included in a file called L8E1.py
. The Python file should include the class definition as well as the demo.