打印用户定义类的对象列表 [英] Printing a list of objects of user defined class

问题描述

所以我有一个类，叫做Vertex.

So I have a class, called Vertex.

class Vertex:
    '''
    This class is the vertex class. It represents a vertex.
    '''

    def __init__(self, label):
        self.label = label
        self.neighbours = []

    def __str__(self):
        return("Vertex "+str(self.label)+":"+str(self.neighbours))

我想打印这个类的对象列表，如下所示:

I want to print a list of objects of this class, like this:

x = [Vertex(1), Vertex(2)]
print x

但它向我展示了这样的输出:

but it shows me output like this:

[<__main__.Vertex instance at 0xb76ed84c>, <__main__.Vertex instance at 0xb76ed86c>]

实际上，我想为每个对象打印 Vertex.label 的值.有什么办法吗?

Actually, I wanted to print the value of Vertex.label for each object. Is there any way to do it?

推荐答案

如果只想打印每个对象的标签，可以使用循环或列表推导式:

If you just want to print the label for each object, you could use a loop or a list comprehension:

print [vertex.label for vertex in x]

但是要回答您原来的问题，您需要定义 __repr__ 方法来获得正确的列表输出.它可能是这样简单的:

But to answer your original question, you need to define the __repr__ method to get the list output right. It could be something as simple as this:

def __repr__(self):
    return str(self)

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