You can use the below-mentioned code for appending a string, just concatenate it with the + sign.
An example is as follows:-
>>> a = "Hello, "
>>> b = "world"
>>> str = a + b
str Hello, world
join connects strings together with a separator. The separator is what you place right before the join.
What join does is it takes a list of strings as a parameter.
To know more about this you can have a look at the following video tutorial:-