1
我的代码:控制台在交互模式下覆盖方法?
class Product:
def __init__(self,name, price,discount):
self.name = name
self.price = price
self.discount = discount
def get_discount_amout(self):
return self.price * self.discount
我复制的代码IPython的控制台,并创建一个实例:
In [2]: book = Product('Think Python', 12.99, 30)
计算折扣金额
In [5]: book.get_discount_amout()
Out[5]: 389.7
我发现拼写错误,算术错误,立即在控制台中纠正它们。首先我定义一个正确的get_discount_amount
函数。
def get_discount_amount_correct(self):
return self.price * self.discount/100
第二次覆盖book
的以前的方法。
book.get_discount_amount = get_discount_amount_correct
测试它。
In [13]: book.get_discount_amount
Out[13]: <function __main__.get_discount_amount_correct>
神奇......然后
In [14]: book.get_discount_amount()
TypeError: get_discount_amount_correct() missing 1 required positional argument: 'self'
尝试,
In [15]: book.get_discount_amount(self)
NameError: name 'self' is not defined
或者尝试拉姆达:
In [16]: book.get_discount_amount = lambda self: self.price * self.discount/100
TypeError: <lambda>() missing 1 required positional argument: 'self'
在控制台中,对象的属性可以很容易地overwrited, 如何o改写它的方法?
您需要修正的方法添加到类('Product'),而不是实例( 'book')。 – jasonharper
它可以在控制台中的script_mode.errors报告中进行修改,Product.get_discount_amount = get_discount_amount_correct',In [26]:Product.get_discount_amount Out [26]: '@jasonharper –