题目：
实现类和函数级的静态变量。
视频教程：
Python入门题032：类和函数级静态变量
代码1：
class People:
Type = '人'
def __init__(self, name):
self.name = name
def show(self):
print(f'{self.name} 是 {self.Type}')
class Teacher(People):
pass
class Student(People):
pass
teacher_li = Teacher('李老师')
student_ming = Student('小明')
student_hong = Student('小红')
print('------ 1')
teacher_li.show()
student_ming.show()
student_hong.show()
print('------ 2')
People.Type = '僵尸'
teacher_li.show()
student_ming.show()
student_hong.show()
print('------ 3')
People.Type = '人'
Student.Type = '僵尸'
teacher_li.show()
student_ming.show()
student_hong.show()
print('------ 4')
People.Type = '人'
teacher_li.show()
student_ming.show()
student_hong.show()
代码2：
def ticktock():
if not hasattr(ticktock, 'counter'):
ticktock.counter = 0
print(f'欢迎光临，这是你第 {ticktock.counter} 次来了!')
ticktock.counter += 1
ticktock()
ticktock()
ticktock()
