面象对象的反射和单列模式

a ="普通变量a"
b ="普通变量b"
A ="普通常量A"
B ="普通常量B"
import sys
def func():
    print("func,function")
def func1():
    print("func1,function")
while 1:
    res = input("<<<:").strip()
    if res.upper() == "Q":
        break
    if hasattr(sys.modules[__name__],res):
        object =getattr(sys.modules[__name__],res)
        if callable(object):
            object()
        else:
            print(object)
    else:
        print("Error")


单例模式

class Teacher:
    flag = None
    def __new__(cls,*args,**kwargs):
        if cls.flag is None:
            cls.flag = object.__new__(cls)
        return cls.flag
    def __init__(self,name):
        self.name = name
alex1 = Teacher("alex")
alex2 = Teacher("alex")
yuan = Teacher("yuan")
print(alex1.name)
print(yuan.name)