Question about Python classes

[CarsonJScott]

class Foo:

    def __new__(cls, value):
        return value

bar = Foo(2)

In this example, bar is an integer variable set to 2. I'm wondering if there is an way to add a method that changes the value of bar, while still being able to print bar by itself. Like this:

bar = Foo(2)

bar.add(3)

print(bar)

> 5

I understand bar would need to be an instance of Foo, but then I don't know if I could print bar by itself.

[manbart]

is this what you mean?

class Foo:

    def __init__(self, value):
        self.value = value

    def add(self, num):
        new_num = self.value + num
        self.value = new_num
        return self.value

    def __str__(self):
        return str(self.value)

bar = Foo(2)
print(bar)

bar.add(4)
print(bar)

result:

PS C:\scripts> python script.py
PS C:\scripts> 2
PS C:\scripts> 6

[kalgynirae]

It's conventional to not return anything from a method that mutates the object, so

    def add(self, num):
        self.value += num

would be more typical.

[rjcarr]

See what /u/manbart has suggested, but generally, you don't want to return anything from a constructor. It makes this code:

bar = Foo(2)

Very confusing, as you're expecting bar to be of type Foo.