Python: Object Has No Attribute Error : An array

Question

class foo:
 #initially
 def __init__(self):
 self.nodes1=[]
 self.nodes2=[]
 self.edges=[]
 def add_node(self,type,x,y):
 if type==1:
 self.nodes1.append(node1(x,y))
class node1:
 def __init__(self,x,y): #Getting coordinates from outside while creating the class.
 self.x=x
 self.y=y
b_foo = foo 
b_foo.add_node(b_foo,1,0,1)

I try to add an element to the class' array. This code gives an error like this:

AttributeError: type object 'bipartite' has no attribute 'nodes1'

• vermanil: You are not creating the instance of class properly. Replace last second line with this b_foo = foo()

Answer 1

You should create an instance of your class:

b_foo = foo() # creates a class instance
b_foo.add_node(1,0,1) # "self" is passed implicitly