Python3递归，避免变量更改以在不同的递归调用中全局反映

def recursive_function(n, result):
    if n == 0:
        return result
    else:
        return recursive_function(n-1, result + n)

result = recursive_function(5, 0)
print(result)  # 输出15

result = 0  # 全局变量

def recursive_function(n):
    global result  # 声明使用全局变量
    if n == 0:
        return result
    else:
        result += n
        return recursive_function(n-1)

result = recursive_function(5)
print(result)  # 输出15