Python/Kivy : Call function from one class to another class and show widget in Python

Question

I am using Python-2.7 and Kivy. When I run test.py then a show button shows. When I click on the show button then a label and value shows. I am fetching it from

Answer 1

You are creating a new Invoice instance instead of using the existing one.

 Invoice().abc()

try instead:

class EditPopup(Popup):
    mode = StringProperty("")
    label_rec_id = StringProperty("Id")
    col_data = ListProperty(["?", "?", "?"])
    index = NumericProperty(0)

    def __init__(self, obj, **kwargs):
        super(EditPopup, self).__init__(**kwargs)
        self.obj = obj # will need it later...

    def update(self,obj):
        #cur.execute("UPDATE `item` SET itemName=?, itemCode=? WHERE itemId=?",
                #('Item1', 9999, 11))
        #con.commit()

        self.obj.abc()  # was Invoice().abc()

Answer 2

Problem

You are instanting a second instance of class Invoice by invoking Invoice().abc() at method update in class EditPopup.

Solution

1) test.py

Comment off Invoice().abc() at method update in class EditPopup and add pass.

def update(self, obj):
    #cur.execute("UPDATE `item` SET itemName=?, itemCode=? WHERE itemId=?",
            #('Item1', 9999, 11))
    #con.commit()
    # Invoice().abc()
    pass

2) test.kv

Add a call to method abc in class EditPopup after call to method update.

    Button:
        size_hint_x: .5
        text: "Ok"
        on_release:
            root.update(root)
            app.root.abc()
            root.dismiss()

Output