I know this sounds stupid, but I'm reading a programming book and they talk about how print() can return nothing (None). They use this code to explain it.
a = 10
b = 15
c = print('a =', a, 'b=', b)
print(c)
I get it, c isn't any data type that print() can take and, y'know, print it. c just has an empty value because it's not a valid data type.
But what data type is c? What data type is None? If c isn't a string, integer, float, nor a boolean, what is it? Shouldn't None be its own data type?
P.S. If I go to python and assign a variable None and print it, it recognises the data value and does not spit a name error. So theoretically, *None is its own data type, right?
Oh, and why does Python not convert c to string and then print it?
None is (like literally everything else in Python besides keywords) an object. Meaning it is an instance of a class (or type if you will). None is an instance of NoneType, which you can find out, if you do this:
print(type(None)) # <class 'NoneType'>
So yes, None has its own data type in Python.
The class is special in the sense that it only ever has one instance: None. And yes, there is a string representation defined for the NoneType class. And the string representation is, well "None", which you see, when you do this: (all equivalent in this case)
print(None)
print(str(None))
print(repr(None))
PS:
It is also worth stressing that None is in fact a singleton. Meaning there only ever is exactly that one instance of the NoneType class. This is why you can do identity comparisons with None, i.e.:
if my_variable is None:
...
As opposed to equality comparisons (which of course work too) like this:
if my_variable == None:
...
And when any function (including built-ins like print) have no explicit return statement or an empty one (like return without anything after it), they implicitly always return that one special None object.