MethodType作用就是把类外面的方法绑定到类或者类的实例上面。使用情况如下

from types import MethodType
def set_score(self, score): #建一个函数
    if 0 <= score <=100:
        self.score = score
    else:
        raise ValueError('should input between 0 and 100)
class Student:
    pass

 第一种情形：将方法绑定到类上

# 将方法绑定到类上
Student.set_score = MethodType(set_score, Student)  # 使用方法 MethodType(函数名， 类名)
s1 = Student()
s2 = Student()
s1.set_score(92)
s2.set_score(95)
print(s1.score, s2.score)
###########################################################################################
C:\Users\zedking\AppData\Local\Programs\Python\Python310\python.exe D:/python/MethodType.py
95 95

Process finished with exit code 0

解析：为什么s1，s2都显示的95呢，因为s1和s2都指向了相同的set_score所在的地址，所有s2把s1的值覆盖了。都显示的95。 

第二种情形: 将方法绑定到实例上

s1 = Student()
s2 = Student()
s1.set_score =MethodType(set_score, s1)
s2.set_score =MethodType(set_score, s2)
s1.set_score(92)
s2.set_score(95)
print(s1.score)
print(s2.score)
########################################################
C:\Users\zedking\AppData\Local\Programs\Python\Python310\python.exe D:/python/MethodType.py
92
95

Process finished with exit code 0

解析：MethodType把方法绑定在类实例上时，每个实例有自己单独的指向区域，互不干扰