自学Python--反射

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反射：多用于网络编程

反射就是通过字符串的形式，导入模块；通过字符串的形式，去模块寻找指定函数，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，一种基于字符串的事件驱动！

hasattr和getattr：

class Info:
    infos = {'teachers':'teachers infos', 'students':'students infos'}

    def show_student(self):
        print('show_student')

    def show_teacher(self):
        print('show_teacher')

    @classmethod
    def func(cls):
        print('classmethod')


print(hasattr(Info, 'test')) # False

if hasattr(Info, 'infos'):
    res = getattr(Info, 'infos')
    print(res) # {'teachers': 'teachers infos', 'students': 'students infos'}

if hasattr(Info, 'func'):
    res = getattr(Info, 'func') # 类方法内存地址
    res() # classmethod

=========================================================================================
class Info:
    infos = {'teachers':'show_teacher', 'students':'show_student'}

    def show_student(self):
        print('show_student')

    def show_teacher(self):
        print('show_teacher')

    @classmethod
    def func(cls):
        print('classmethod')


info = Info()

if hasattr(info, 'infos'):
    res = getattr(info, 'infos')
    for i in res:
        if hasattr(info, res[i]):
            getattr(info, res[i])() # show_teacher show_student

反射模块时第一个参数为模块名

反射自己模块时：

import sys

def f():
    print('f')

current_module = sys.modules[__name__] # 获取本模块对象
res = getattr(current_module, 'f')
res() # f

设置修改变量：setattr

删除变量：delattr