Python Forum

I'm trying to learn how to make Python classes by following along with a tutorial video. One of the examples goes like this:

import bpy

class SquareFaceCube:
    """
    a class to represent a cube mesh object with square faces
    """
    def _init_(self):
        self.verts=[
            (-1.0,-1.0,-1.0),
            (-1.0,1.0,-1.0),
            (1.0,1.0,-1.0),
            (1.0,-1.0,-1.0),
            (-1.0,-1.0,1.0),
            (-1.0,1.0,1.0),
            (1.0,1.0,1.0),
            (1.0,-1.0,1.0),
        ]

        self.faces=[
            (0,1,2,3),
            (0,4,5,1),
            (1,5,6,2),
            (2,6,7,3),
            (0,3,7,4),
            (4,7,6,5),
        ]
        
        self.mesh_data=None
        self.mesh_object=None
    
    def create_mesh_data(self):
        """
        create mesh data from verts and faces data
        """
        self.mesh_data=bpy.data.meshes.new("cube_data")
        self.mesh_data.from_pydata(self.verts,[],self.faces)
    
    def create_mesh_object_from_data(self):
        """
        create object from mesh data
        """
        self.mesh_object=bpy.data.objects.new("cube_object",self.mesh_data)
    
    def add_mesh_object_to_scene(self):
        """
        add object into active scene by linking the object to the
        default scene collection
        """
        bpy.context.collection.objects.link(self.mesh_object)
    
    def create_mesh_object(self):
        """
        create mesh object from data and add new object
        into the scene
        """
        self.create_mesh_data()
        self.create_mesh_object_from_data()
        self.add_mesh_object_to_scene()
    
    def add_into_scene(self, location):
        if self.mesh_object==None:
            self.create_mesh_object()
            self.mesh_object.location=location
        else:
            print("Warning: can't add mesh object because it is already added to the scene")

def main():
    square_face_cube=SquareFaceCube()
    square_face_cube.add_into_scene(location=(0,0,0))

if __name__=="__main__":
    main()

I copied the whole script to try and do it my self but for some reason I keep coming out with this error message.

Error:
Python: Traceback (most recent call last):
  File "C:\Users\jacob\OneDrive\Documents\Blender\Blender Custom UI\Blender Custom UI.blend\Class ex 1", line 72, in <module>
  File "C:\Users\jacob\OneDrive\Documents\Blender\Blender Custom UI\Blender Custom UI.blend\Class ex 1", line 69, in main
  File "C:\Users\jacob\OneDrive\Documents\Blender\Blender Custom UI\Blender Custom UI.blend\Class ex 1", line 61, in add_into_scene
AttributeError: 'SquareFaceCube' object has no attribute 'mesh_object'

One of the first variables in self.mesh_object. Can someone please tell me what I am doing wrong with this code?

the_jl_zone Wrote:One of the first variables in self.mesh_object. Can someone please tell me what I am doing wrong with this code?

"==" i think you mean "=" common mistake when first learning python

You need __init__ (double underscores), not _init_. The single underscores around init result in the method not being called when our create an instance.

Are you running this Python script inside Blender? Would you mind sharing which tutorial is this?