Question

I have a small Python OOP program in which 2 class, Flan and Outil inherit from a superclass Part.
My problem is when I call Flan everything works perfectly, however when I call Outil the program fails silently.
The Outil instance is created, but it lacks all the attributes it doesn’t share with Part.
The Outil instance isn’t added to Outil.list_instance_outils, nor to Part.list_instances.

class Outil(Part):

    list_instance_outils = []    

    def __init___(self, name, part_type, nodes, elems):
        Part.__init__(self, name, part_type, nodes, elems)
        self.vect_norm = vectnorm(self.nodes[self.elems[0,1:]-1, 1:])
        self.elset = Elset(self)
        self.nset = Nset(self, refpoint=True, generate=False)
        self.SPOS = Ab_surface(self, self.elset)
        self.SNEG = Ab_surface(self, self.elset, type_surf='SNEG')
        Outil.list_instance_outils.append(self)
        Part.list_instances.append(self)

class Flan(Part):

    list_instances_flans = []    

    def __init__(self, name, part_type, nodes, elems):
        Part.__init__(self, name, part_type, nodes, elems)       
        self.vect_norm = vectnorm(self.nodes[self.elems[0,1:4]-1, 1:])
        self.elset = Elset(self)
        self.nset = Nset(self)
        self.SPOS = Ab_surface(self, self.elset)
        self.SNEG = Ab_surface(self, self.elset, type_surf='SNEG')
        Flan.list_instances_flans.append(self)        
        Part.list_instances.append(self)

Both this Classes inherit from Part :

class Part():

    list_instances = []

    def __init__(self, name, part_type, nodes, elems):
        self.name = name
        self.name_instance = self.name + '-1'
        self.part_type = part_type
        self.elems = elems
        self.nodes = nodes
        offset = np.min(self.elems[:, 1:])-1
        self.nodes[:, 0] -= offset
        self.elems[:, 1:] -= offset

I cannot stress enough that I have no error message whatsoever.
What am I doing wrong here ?

Answer 1

You wrote __init__ with three trailing underscores instead of two in Outil.

Because of this, it doesn’t get called — Part.__init__ gets called instead. That’s why the class is created but it lacks the attributes beyond what are in Part.