def testpush(i, result=[]):
    if i == 5:
        return result
    i += 1
    result.append(i)
    return testpush(i, result)


result = testpush(0)
result = testpush(0)
result = testpush(0)
print(result)

结果是这样
[1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5]

def testpush(i, result=[]):
    if i == 5:
        return result
    i += 1
    result.append(i)
    return testpush(i, result)


result = testpush(0, [])
result = testpush(0, [])
result = testpush(0, [])
print(result)

结果是这样
[1, 2, 3, 4, 5]

请问函数默认变量的作用域是怎样的？为什么会出现上面两种不同的情况？