《Python编程从入门到实践》中出现的问题

Question

这本书在讲解类时举了个例子

class Car:
    def __init__(self, make, model, year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0

    def get_descriptive_name(self):
        long_name = f"{self.year} {self.make} {self.model}"
        return long_name.title()

    def read_odometer(self):
        print(f"This car has {self.read_odometer()} miles on it. ")

my_new_car = Car('audi', 'a4', 2019)
print(my_new_car.get_descriptive_name())
my_new_car.read_odometer()

但是我在我自己电脑上运行此代码，编译器报错了：

Traceback (most recent call last):
  File "D:\PycharmProjects\python_work\car.py", line 22, in <module>
    my_new_car.read_odometer()
  File "D:\PycharmProjects\python_work\car.py", line 18, in read_odometer
    print(f"This car has {self.read_odometer()} miles on it. ")
  File "D:\PycharmProjects\python_work\car.py", line 18, in read_odometer
    print(f"This car has {self.read_odometer()} miles on it. ")
  File "D:\PycharmProjects\python_work\car.py", line 18, in read_odometer
    print(f"This car has {self.read_odometer()} miles on it. ")
  [Previous line repeated 996 more times]
RecursionError: maximum recursion depth exceeded

我刚刚学Python，不是很懂为什么。

Answer 1

 def read_odometer(self):
        print(f"This car has {self.read_odometer()} miles on it. ")

你在print里面引用了函数本身，这个函数本身又会引用自身，于是造成死循环
你可以直接把保存信息扔进百度搜索，通过百度翻译也能了解其含义

递归错误：你在函数内引用了自身，这一过程出错了
超过最大递归深度：一般是陷入了死循环