(Python3) Is there a way to str1 -= str2? : I know -= operation doesn't work in str.

But is there a function that works the same?

The reason why I need this is because

    def function(self, str_source):
        str_source = str_source[:-1] # removing last character of the string
        str_source += self.other_function() # adding other characters
        return True

in this sort of function, when I do s = s[:-1], the original string does not change.

I know why it does not change, and I know I can just return another modified string, but I am currently working on someone else's codes that I can't complete rip off the Project.

So is it possible to remove the substring of a string in a function?