Difference between + and , in python3

Question

I'm a little confused, if you try:
variable = 10;
print(variable, "hello!");

the code Will run, why?

if you try this:

variable = 10;
print(variable + "hello!");

I will get an error, can someone explain me the difference between using + and ,?

Answer 1

The comma separates the results and print function prints them both.
n = 10, h = 'hi'
print(h, 'ho')
-> hi ho

The add "+" operator can add two numbers or concat strings but not number and string
print(n + 20) -> 30
print('2' + '3N') -> 23N
print(n + 'hi') #error

Answer 2

operator + is not defined for int,string.

But print(a,b,c....) is independent of type of a,b,c....
the system looks up the appropiate representation of the type.

Answer 3

using + is a math operator. it wants to add numbers and you are only giving it 1 number. the comma is for concatenation. it just places whatever you want on the line. you could convert the number to a string like this...
str(variable) or variable = str(10)
then you can use the plus sign. Also when you use a comma it will automatically add a space. The plus won't.
Hope this helps.