Class member become static - Printable Version

Class member become static - Printable Version

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Class member become static - Quasar999 - Sep-14-2023

In the following code data must be an non static attribute of the class Node:

class Node:
    total = 0
    def __init__(self,parent,data):
        Node.total=Node.total+1
        self.index=Node.total
        self.data = data
        if self.index!=1:
            self.parent = parent.index
            self.depth=parent.depth+1
        else:
            self.parent=1
            self.depth=0

list=[Node(0,[2,2,2,2,2,2])]
i=0
while list[i].depth<2:
    for j in range(0,6):
        p_data=list[i].data
        num=p_data[j]
        if num!=0:           
            p_data[j]=0
            for k in range(1,num+1):
                p_data[(j+k)%6]=p_data[(j+k)%6]+1
            list.append(Node(list[i],p_data))
    i=i+1

For every class instance in list all member have the same value for member data and also become static.

RE: Class member become static - deanhystad - Sep-16-2023

Do not use "list" as a variable name. list() is a built-in function that creates a list.

There are no "static" variables in Python. "total" is a class variable.

Your problem is here:

        p_data=list[i].data

p_data and list[1].data are the same list object. Even though "data" is an instance variable that references a list, all instances of Node end up referencing the same list object. Do you want each node to have their own list? You could do this:

        p_data=list[i].data.copy()

Now p_data and list[1].data are different lists. They have the same contents, but they are different list objects. When you create a new Node using pdata, the data in the old Node and the new Node will be different lists.