When should I use "parent=None" in __ini__ and "parent" in super()

[Randy Johnson]

Those are contradictory for what you are trying to accomplish unless it is a Parent - Child relationship  (MainWindow - Window):

When you super() an object, it enherits all the properties from its parent object.

Source: 
https://www.w3schools.com/python/python_inheritance.asp

If what you want is 2 windows, you can define 2 instances of both Classes and run both at the end. 

```

class User1(object):
    def __init__(self, fname, age, parent=None):
        self.fname = fname
        self.age = int(age)

        # Calling the return function that prints the details
        self.return_user()

    def return_user(self):
        print(self.fname)
        print(self.age)


class User2(object):

    def __init__(self, lname, height, parent=None):

        self.lname = lname
        self.height = float(height)
        self.return_user()

    def return_user(self):
        print(self.lname)
        print(self.height, "CM")
        print((self.height / 2.54), "IN")


User1("Hugh", 21)
User2("Janus", 175.26)
```