In Python, data types (like int, float) both represent a value, but also have some built-in attributes/functions/etc:

In [1]: a = 1.2

In [2]: a
Out[2]: 1.2

In [3]: a.is_integer()
Out[3]: False

Is it possible to reproduce this behavior within Python, e.g. define a class:

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

    # other code ....

s = Scalar(1.2)

where I could have s return 1.2 (instead of typing s.value), and do things like a = s -> a = 1.2? The closest I can get to this behavior is adding something like:

def __getitem__(self, key=None):
    return self.value

and using a = s[()], but that doesn't look very good.

where I could have s return 1.2 (instead of typing s.value)

In the console? Then implement the __repr__ method.

a = s -> a = 1.2

To avoid having to use a = s.value, you can implement __call__ and call the object:

>>> class Scalar:
...     def __init__(self, value):
...         self.value = value
...     def __repr__(self):
...         return str(self.value)
...     def __call__(self):
...         return self.value
...
>>> s = Scalar(1.2)
>>> s
1.2
>>> a = s()
>>> a
1.2

Check the documentation about the data model on emulating numeric types.

For example:

class Scalar:
    def __init__(self, value):
        self.value = value
    def __repr__(self):
        return str(self.value)
    def __call__(self):
        return self.value
    def __add__(self, other):
        return Scalar(self.value + other.value)
    def __lt__(self, other):
        return self.value < other.value
    def ___le__(self, other):
        return self.value <= other.value
    def __eq__(self, other):
        return self.value == other.value
    def __ne__(self, other):
        return self.value != other.value
    def __gt__(self, other):
        return self.value > other.value
    def __ge__(self, other):
        return self.value >= other.value

Can be used like this:

>>> s1 = Scalar(1.2)
>>> s2 = Scalar(2.1)
>>> s1 + s2
3.3
>>> s1 < s2
True
>>> s1 > s2
False
>>> s1 != s2
True
>>> s1 <= s2
True
>>> s1 >= s2
False

There are also the __int__ and __float__ magic methods, which you can implement and use like this (this is more semantically correct):

>>> a = int(s)
>>> a = float(s)