如何更改结构中变量的值？

#include <stdio.h>

struct Person {
    char name[20];
    int age;
};

int main() {
    struct Person person;
    strcpy(person.name, "John");
    person.age = 25;

    printf("Before change: %s, %d\n", person.name, person.age);

    strcpy(person.name, "Alice");
    person.age = 30;

    printf("After change: %s, %d\n", person.name, person.age);

    return 0;
}

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

person = Person("John", 25)
print("Before change:", person.name, person.age)

person.name = "Alice"
person.age = 30

print("After change:", person.name, person.age)