python 反射机制

 反射也叫路由系统，就是通过字符串的形式导入模块；通过字符串的形式去模块中寻找指定的函数，并执行，利用字符串的形式去对象（模块）中操作（查找、获取、删除、添加）成员，一种基于字符串的时间驱动。

获取：（getattr：获取或执行对象中的对象）

class NameList():
    def __init__(self,name,age):
        self.name = name
        self.age = age

    def Show(self):
        print("My name is %s and I'm %d years old" %(self.name,self.age))

obj = NameList("Adair",18)
# obj.Show()
UserInput=input(">>>")
print(getattr(obj,UserInput))

>>>name
Adair

>>>age
18

>>>Show
<bound method NameList.Show of <__main__.NameList object at 0x000001F6CADEB358>>

getattr 调用函数：
class NameList():
    def __init__(self,name,age):
        self.name = name
        self.age = age

    def Show(self):
        print("My name is %s and I'm %d years old" %(self.name,self.age))

obj = NameList("Adair",18)
# obj.Show()
UserInput=input(">>>")
Get = getattr(obj,UserInput)
Get()

>>>Show
My name is Adair and I'm 18 years old

查找：（hasattr:判断方式是否存在与对象中）

class NameList():
    def __init__(self,name,age):
        self.name = name
        self.age = age

    def Show(self):
        print("My name is %s and I'm %d years old" %(self.name,self.age))

obj = NameList("Adair",18)
UserInput=input(">>>")
print(hasattr(obj,UserInput))

>>>name
True

>>>Show
True

>>>Adair
False

添加/修改（setattr）

class NameList():
    def __init__(self,name,age):
        self.name = name
        self.age = age

    def Show(self):
        print("My name is %s and I'm %d years old" %(self.name,self.age))

obj = NameList("Adair",18)
InputKey=input(">>>")
InputValue=input(">>>")
New = setattr(obj,InputKey,InputValue)
print(getattr(obj,InputKey))

>>>salary
>>>100000
100000


>>>name
>>>xiaohei
xiaohei

删除：（delattr）

class NameList():
    def __init__(self,name,age):
        self.name = name
        self.age = age

    def Show(self):
        print("My name is %s and I'm %d years old" %(self.name,self.age))

obj = NameList("Adair",18)
UserInput=input(">>>")
delattr(obj,UserInput)
print(hasattr(obj,UserInput))

>>>name
False

注：getattr,hasattr,setattr,delattr对模块的修改都在内存中进行，并不会影响文件中真实内容。