Python OOP - 在类中调用方法

Question

I am new in Python OOP and I am trying to understand one line of this Code (This is just a part of the whole Code)

I am trying to understand what "pet.name" in the methode "whichone" do. The parameter 'petlist' in whichone can be empty or a list with strings. The Parameter 'name' has just one string.

Can someone explain me what "pet.name" actually do?

from random import randrange

class Pet():
    boredom_decrement = 4
    hunger_decrement = 6
    boredom_threshold = 5
    hunger_threshold = 10
    sounds = ['Mrrp']
    def __init__(self, name = "Kitty"):
        self.name = name
        self.hunger = randrange(self.hunger_threshold)
        self.boredom = randrange(self.boredom_threshold)
        self.sounds = self.sounds[:]  


def whichone(petlist, name):
    for pet in petlist:
        if pet.name == name:
            return pet
    return None # no pet matched

def play():
    animals = []

    option = ""
    base_prompt = """
        Quit
        Choice: """
    feedback = ""
    while True:
        action = input(feedback + "\n" + base_prompt)
        feedback = ""
        words = action.split()
        if len(words) > 0:
            command = words[0]
        else:
            command = None
        if command == "Quit":
            print("Exiting...")
            return
        elif command == "Adopt" and len(words) > 1:
            if whichone(animals, words[1]):
                feedback += "You already have a pet with that name\n"
            else:
                animals.append(Pet(words[1]))

play()

Answer 1

Each Pet has a name that you give when constructing an object, that being pet.name ("Kitty" by default).

I assume whichdone() is supposed to get a list of Pet objects and query them against name argument. It will return the first Pet whose name matches a name that you've used as input to whichdone() .

Answer 2

Assuming the petlist parameter is a List of Pet objects, then the for pet in petlist line will iterate through the list and you will be able to use the pet variable to access the current element.

What is happening in the for loop is that you check whether the current object has the name you passed as a second parameter of the whichone function. To do this, you'll need to access the name attribute of the object stored in the pet variable (which is assumed to be of type Pet ). The Python syntax for this is pet.name ( <variable_name>.<attribute_name> ).
You know of the existence of this attribute thanks to the class definition, to the __init__ method, where you can see the new instance of the Pet class will receive a name upon creation (which is defaulted to "Kitty").