Day 17 – 自定义类（Class）

自定义类

类定义的语法，如下

# 类的定义, ClassName必须首字母大写
class ClassName:

# 类的对象
class_name_1 = ClassName()

构造器（初始化器）

Python 的初始化器为__init__方法

class ClassName:
	def __init__(self):
	# 将属性进行初始化

类的属性

属性的初始化操作在构造器中进行

# 属性的定义
class ClassName:
	def __init__(self, attribute_1, attribute_2, ...)
		self.attribute_a = attribute1
		self.attribute_b = attribute2
		...

# 对象属性的使用
class_name_1 = ClassName(attribute_1, attribute_2, ...)

类的方法

类的方法定义，如下所示

class ClassName:
	# 初始化器（构造器）
	def __init__(self, attribute_1, attribute_2, ...)
		self.attribute_a = attribute1
		self.attribute_b = attribute2
		...
	# 方法定义
	def function_a(self, class_name):
		# 方法的内部实现

# 对象方法的使用
class_name_1 = ClassName(attribute_1, attribute_2, ...)
class_name_2 = ClassName(attribute_1, attribute_2, ...)
class_name_1.function_a(class_name_2)

Quiz 游戏

main.py 文件内容

from question_model import Question
from data import question_data
from quiz_brain import QuizBrain

question_bank = []
for question in question_data:
    question_bank.append(Question(question["text"], question["answer"]))

quiz = QuizBrain(question_bank)
while quiz.still_has_question():
    quiz.next_question()

print("You've completed the quiz.")
print(f"Your final score was: {quiz.score}/{quiz.question_number}")

quiz_brain.py文件内容

class QuizBrain:
    def __init__(self, q_list):
        """类初始化"""
        self.question_number = 0
        self.question_list = q_list
        self.score = 0

    def next_question(self):
        """下一个问题"""
        current_question = self.question_list[self.question_number]
        self.question_number += 1
        user_answer = input(f"Q.{self.question_number}: {current_question.text} (True/False)?: ")
        self.check_answer(user_answer, current_question.answer)

    def still_has_question(self):
        """是否还有问题，有返回 True， 否则返回 False"""
        return self.question_number < len(self.question_list)

    def check_answer(self, user_answer, current_answer):
        """检测用户答案"""
        if user_answer == current_answer:
            self.score += 1
            print("You got it right!")
        else:
            print("That's wrong.")
        print(f"The correct answer was {current_answer}.")
        print(f"Your current score was {self.score}/{self.question_number}")

question_model.py文件内容

class Question:

    def __init__(self, q_text, q_answer):
        """属性初始化"""
        self.text = q_text
        self.answer = q_answer

data.py文件内容

question_data = [
{"text": "A slug's blood is green.", "answer": "True"},
{"text": "The loudest animal is the African Elephant.", "answer": "False"},
{"text": "Approximately one quarter of human bones are in the feet.", "answer": "True"},
{"text": "The total surface area of a human lungs is the size of a football pitch.", "answer": "True"},
{"text": "In West Virginia, USA, if you accidentally hit an animal with your car, you are free to take it home to eat.", "answer": "True"},
{"text": "In London, UK, if you happen to die in the House of Parliament, you are entitled to a state funeral.", "answer": "False"},
{"text": "It is illegal to pee in the Ocean in Portugal.", "answer": "True"},
{"text": "You can lead a cow down stairs but not up stairs.", "answer": "False"},
{"text": "Google was originally called 'Backrub'.", "answer": "True"},
{"text": "Buzz Aldrin's mother's maiden name was 'Moon'.", "answer": "True"},
{"text": "No piece of square dry paper can be folded in half more than 7 times.", "answer": "False"},
{"text": "A few ounces of chocolate can to kill a small dog.", "answer": "True"}
]