I'm learning Python lately (Dec.'20) and found this concept is very convoluted. Let's say I have a function. How can I tell if a particular objects type can be applied to this kind of function overloading?
def compute(a, b, c):
return (a+b) * c
It works fine with some of these object type - number, string, but not others.
>>> a, b, c=1,2,3
>>> a, b, c = 'hi', 'U', 3 # okay
>>> a, b, c = [1], [2,3], 3 # okay
>>> a, b, c = {1}, {2}, 3 # it's set()
Taking the + as an example, a data type must implement the __add__() (magic/special/"dunder") method to meaningfully use the + operator. In your examples, it is defined for integers, strings and lists, but not for sets.
The Python Data Model is the reference document if you want to learn more about this topic, but as a starting point you may find this article useful.
If you want to know whether a particular object, say x has an operator overloaded, or what we call magic method in Python, you can check:
hasattr(x, '__add__') # for + and similarly for any other.
Of course, you can define one such method for a class you want, if it does not exist.
"string" * 3 = "stringstringstring"however where you have used {} curley bracket. These cannot have maths done to them{1} - {2}is legal. The problem is that sets don't support+.