Question

我有一点工作，显然改变了一些东西，因为它不再起作用。这是一个更大的代码的一部分，但我已经找出了更好的问题区域。我正在运行一个while语句，让用户输入一个数字来扩展或缩小（如果是负数）一个矩形。

我得到了输出：

How much would you like to expand or shrink r by? 3
Rectangle r expanded/shrunk =  <__main__.Rectangle object at 0x000000000345F5F8>
Would you like to try expanding or shrinking again? Y or N

我应该得到“矩形（27,37,106,116）”而不是＆lt; _main line

我知道这是一个简单的问题，我只是忽略了，我需要有人帮助指出它。这是我的代码......

class Rectangle:
    def __init__(self, x, y, w, h):
        self.x = x
        self.y = y
        self.w = w
        self.h = h

    def expand(self, expand_num): # Method to expand/shrink the original rectangle
        return Rectangle(self.x - expand_num, self.y - expand_num, self.w + expand_num * 2, self.h + expand_num * 2)

r_orig = Rectangle(30,40,100,110)


try_expand = 0
while try_expand != "N" and try_expand !="n":
    input_num = input("How much would you like to expand or shrink r by? ")
    expand_num = int(input_num)
    print("Rectangle r expanded/shrunk = ", r_orig.expand(expand_num))
    try_expand = input("Would you like to try expanding or shrinking again? Y or N  ")
    print("")

我已经搜索过其他类似的问题了，似乎问题可能是某个地方的括号，但我只是没有看到它。提前感谢任何发现问题的人。

顺便说一句 - 我对此很新，所以请原谅任何礼仪/编码/短语错误

Answer 1

您应该为您的班级添加__repr__方法。例如：

class Rectangle:
    def __init__(self, x, y, w, h):
        self.x = x
        self.y = y
        self.w = w
        self.h = h

    def expand(self, expand_num): # Method to expand/shrink the original rectangle
        return Rectangle(self.x - expand_num, self.y - expand_num, self.w + expand_num * 2, self.h + expand_num * 2)

    def __repr__(self):
        return "Rectangle("+str(self.x)+", " + str(self.y)+ ", " + str(self.w) + ", " + str(self.h) + ")"
r_orig = Rectangle(30,40,100,110)


try_expand = 0
while try_expand != "N" and try_expand !="n":
    input_num = input("How much would you like to expand or shrink r by? ")
    expand_num = int(input_num)
    print("Rectangle r expanded/shrunk = ", r_orig.expand(expand_num))
    try_expand = input("Would you like to try expanding or shrinking again? Y or N  ")
    print("")

请参阅http://docs.python.org/2/reference/datamodel.html#object.__repr__

无法找到语义问题

1 个答案: