如何在使用函数返回名称后重用它？

name = get_name()
print("Hello, " + name)

name = None

def get_name():
    global name
    name = "John Doe"

get_name()
print("Hello, " + name)

class Person:
    def __init__(self):
        self.name = None

    def get_name(self):
        self.name = "John Doe"

person = Person()
person.get_name()
print("Hello, " + person.name)