反射:用字符串数据类型的变量来访问这个变量的值.
反射主要用到getattr,hasattr 其次是setattr,delattr
# 什么是反射?
# 用字符串数据类型的变量名来访问这个变量的值
# 反射的方法: getattr hasattr setattr delattr
# class Student:
# def __init__(self,name):
# self.name = name
# def check_course(self):
# print('check_course')
# def choose_course(self):
# print('choose_course')
# def choosed_course(self):
# print('查看已选择的课程')
# stu = Student()
# num = input('>>>')
# if num == 'check_course':
# stu.check_course()
# elif num == 'choose_course':
# stu.choose_course()
# elif num == 'choosed_course':
# stu.choosed_course()
# eval 这个东西 明确的写在你的代码里
# 类 静态属性 类方法 静态方法
# 命名空间.XXX == getattr(命名空间,'XXX')
# class Student:
# ROLE = 'STUDENT'
# @classmethod
# def check_course(cls):
# print('查看课程了')
#
# @staticmethod
# def login():
# print('登录')
# # 反射查看属性
# # print(Student.ROLE)
# # print(getattr(Student,'ROLE'))
#
# # 反射调用方法
# # getattr(Student,'check_course')() # 类方法
# # getattr(Student,'login')() # 静态方法
#
# num = input('>>>')
# if hasattr(Student,num):
# getattr(Student,num)()
# 对象
# 方法 对象属性
# class A():
# def __init__(self,name):
# self.name = name
#
# def func(self):
# print('in func')
#
# a = A('alex')
# print(a.name)
# print(getattr(a,'name'))
# getattr(a,'func')()
# 模块
# import os # 别人写好的python代码的结合
# # os.rename('__init__.py','init')
# # getattr(os,'rename')('init','__init__.py') # == os.rename
# rename = os.rename
# rename2 = getattr(os,'rename')
# rename2('__init__.py','init') # os.rename('__init__.py','init')
# rename('init','init2') # os.rename('init','init2')
# def wahaha():
# print('wahaha')
#
# def qqxing():
# print('qqxing')
# 反射自己模块中的内容 找到自己当前文件所在的命名空间
# wahaha()
# qqxing()
# import sys
# print(sys.modules)
# import 都相当于导入了一个模块
# 模块哪个导入了 哪个没导入 在我的python解释器里应该记录下来
# import sys 是一个模块,这个模块里的所有的方法都是和python解释器相关的
# sys.modules 这个方法 表示所有在当前这个python程序中导入的模块
# '__main__': <module '__main__' from 'D:/sylar/python_workspace/day20/4.反射.py'>
# print(sys.modules['__main__'])
# my_file = sys.modules['__main__']
# my_file.wahaha()
# my_file.qqxing()
# # 'qqxing'
# # 'wahaha'
# getattr(my_file,'wahaha')()
# getattr(my_file,'qqxing')()
# 反射
# hasattr,getattr
# 类名.名字
# getattr(类名,'名字')
# 对象名.名字
# getattr(对象,'名字')
# 模块名.名字
# import 模块
# getattr(模块,'名字')
# 自己文件.名字
# import sys
# getattr(sys.modules['__main__'],'名字')
# 选课系统的代码
# login
# 判断身份 并且根据身份实例化
# 根据每个身份对应的类 让用户选择能够做的事情
# class Manager:
# OPERATE_DIC = [
# ('创造学生账号', 'create_student'),
# ('创建课程','create_course'),
# ('查看学生信息','check_student_info'),
# ]
# def __init__(self,name):
# self.name = name
# def create_student(self):
# print('创建学生账号')
# def create_course(self):
# print('创建课程')
# def check_student_info(self):
# print('查看学生信息')
#
# class Student:
# OPERATE_DIC = [
# ('查看所有课程', 'check_course'),
# ('选择课程', 'choose_course'),
# ('查看已选择的课程', 'choosed_course')
# ]
# def __init__(self,name):
# self.name = name
# def check_course(self):
# print('check_course')
# def choose_course(self):
# print('choose_course')
# def choosed_course(self):
# print('查看已选择的课程')
#
# def login():
# username = input('user : ')
# password = input('pwd : ')
# with open('userinfo') as f:
# for line in f:
# user,pwd,ident = line.strip().split('|') # ident = 'Manager'
# if user == username and pwd == password:
# print('登录成功')
# return username,ident
#
# import sys
# def main():
# usr,id = login()
# print('user,id :',usr,id)
# file = sys.modules['__main__']
# cls = getattr(file,id) #Manager = getattr(当前文件,'Manager')
# obj = cls(usr)
# operate_dic = cls.OPERATE_DIC
# while True:
# for num,i in enumerate(operate_dic,1):
# print(num,i[0])
# choice = int(input('num >>>'))
# choice_item = operate_dic[choice-1]
# getattr(obj,choice_item[1])()
#
#
#
# main()
# l = ['a','b','c']
# for num,i in enumerate(l,1):
# print(num,i)
# class A:
# def __init__(self,name):
# self.name = name
#
# a = A('alex')
# # a.name = 'alex_SB'
# # getattr(a,'name')
# setattr(a,'name','alex_SB')
# print(a.name)
# print(a.__dict__)
# del a.name
# print(a.__dict__)
# delattr(a,'name')
# print(a.__dict__)