Question

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))

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

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

but it shows me output like this:

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

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

Answer 1

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]

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)