Question

Hi guys!

I have a small problem, i can’t verbally explain the problem, so i’ll just try to illustrate it in code:

class move(object):
    def __init__(self, number):
        self.number = number

list1 = [move(1), move(2), move(3), move(4)]
list2 = [move(3), move(7)]

list1.remove(list2[0])

Traceback (most recent call last):
  File "<pyshell#6>", line 1, in <module>
    list1.remove(list2[0])
ValueError: list.remove(x): x not in list

As you can see, list1[2] and list2[0] are both derived from the same class and have the exact same attributes, they are only two different instances of this class

What is the optimal solution to this problem?

Thank you very much for your help!

Answer 1

You should override the __eq__ of your class to tell Python that two classes are equal if their numbers are equal:

class move(object):
    def __init__(self, number):
        self.number = number

    def __eq__(self, other):
        return self.number == other.number