day06-codes and exercise in class

# Author: Ghost
# Email: jiaci.liu@gmail.com

'''
1-Review of last week
2-interface class, abstract class
3-packing
4-special methods
    classmethod
    staticmethod
    property
5-reflection  ******************
    __hasattr__
    __getattr__
    __setattr__
    __delattr__
6-advanced special methods
    __call__
    __new__
    __getitem__
    __setitem__
    __delitem__
7-time, random,
'''

'''
Review: combination
'''
# class A:
#     name = 'alex'
#     def __init__(self, name1, age1):
#         self.name1 = name1
#         self.age1 = age1
#
#     def func(self):
#         print(self.name1)
#         print(self.name)
#
#     def func1(self):
#         print(self.age1)
#
# class B:
#     name2 = 'xiaobai'
#     def func3(self):
#         print('in func3')
#
# obj = A('isa', 24)
# objB = B()
#
# obj.new = objB
# print(obj.new.name2)

# class A:
#     n1 = '太白'
#
#     def __init__(self, name1, age1):
#         self.name = name1
#         self.age = age1
#
#     def func(self):
#         print(self.name)
#         self.func1()
#         print(self.n1)
#         print(666)
#
#     def func1(self):
#         print(777)
#
# obj = A('alex', 73)
# # obj.func()
#
# class B:
#     n2 = 'WuSir'
#
#     def func3(self):
#         print('in func3')
#
# b1 = B()
# obj.b = b1  # 组合 给对象新添加了一个属性'b'
# print(obj.b.n2)
# print(obj.__dict__)

'''
single inheritage
'''

# class A:
#     name = 'alex'
#
#     def func(self):
#         print('IN A')
#
#
# class B(A):
#     name = '太白'
#
#     def func(self):
#         # 下面两种表示方法作用相同：
#         # A.func(self)
#         # super().func()
#         # super放前面则先执行A中的function， super放后面则先执行B中的
#         print('IN b')
#         super().func()
#
#
# obj = B()
# print(obj.name)
# obj.func()

# 1. seek for 'name/obj' in current class first,
# if 'name/obj' exists, then execute, otherwise parent class will be checked
# 2. if attributes of parent class require to be inherited,
# attributes with exact names should not be defined in current class

'''
execution sequence of dynamic and static attributes (functions)
1. seek for __init__() and execute it
2. seek for destination function in current object-->current class of the object-->parent class
'''
# class Parent:
#     def func(self):
#         print('in Parent func')
#
#     def __init__(self):
#         self.func()
#
# class Son(Parent):
#     def func(self):
#         print('in Son func')
#
# son1 = Son()

# class Parent:
#     def func(self):
#         print(self.name)
#         print('parent')
#
#     def __init__(self, name):
#         self.name = name
#
# class SON(Parent):
#     def func(self):
#         print('son')
# obj = SON('xiaobai')
# obj.func()

'''
Interview questions:
1. attributes assignment inside of functions of a class cannot be referenced, eg.:c, t;
2. corresponding attributes of class cannot be reassigned if they were only reassigned in object;
'''
# class A:
#     a = 0
#     b = 1
#     def __init__(self):
#         c = 222
#
#     def func(self):
#         t = 444
#
# d = A()
# d.a = 'new a'
# d.b = 'new b'
# d.c = 'new c'
# print(d.__dict__)
# print(A.__dict__)  # c, t are not inside of the dict of Class A
#
# print(A.c)  # AttributeError: type object 'A' has no attribute 'c'
# print(A.t)  # AttributeError: type object 'A' has no attribute 'c'

'''
interface class
'''
# from abc import ABCMeta, abstractmethod
# class Pay(metaclass=ABCMeta):
#     @abstractmethod
#     def pay(self, money):
#         pass
#
# class AliPay(Pay):
#     def pay(self, money):
#         print('alipay %s' % money)
#
# class wechat(Pay):
#     def pay(self, money):
#         print('wechat %s' % money)
#
# class QQpay(Pay):
#     def qqpay(self, money):
#         print('qqpay %s' % money)
#
# obj = QQpay()
# obj.qqpay(11) # TypeError: Can't instantiate abstract class QQpay with abstract methods pay

'''
packing of class:
# 私有成员：私有变量,私有对象属性，私有方法
# 私有成员：类外面不可以访问，派生类不可以访问，类内面可以访问
'''
# class A:
#     normattr = 'this is a normal attribute'
#     __name = 'this is a private attribute'
#
#     def __init__(self, name, item):
#         self.name = name  # normal object attribute
#         self.__privateattr = item  # private object attribute
#
#     def func1(self):
#         print('this is a normal function')
#         self.__privatefunc()
#
#     def __privatefunc(self):
#         print(self.__name)
#         print('this is a private object function')
#
#     @property
#     def func2(self):
#         pass
#
#     @staticmethod
#     def func3():
#         pass
#
#     @classmethod
#     def func4(cls):
#         pass
#
# class AA(A):
#     pass
#
# obj = A('parent class', 12)
# # obj.__privatefunc()  # AttributeError: type object 'A' has no attribute '__privatefunc'
# # obj.__name  # AttributeError: 'A' object has no attribute '__name'
# # obj.func1()
#
# son = AA('son class', 12)
# # son.__name  # AttributeError: 'AA' object has no attribute '__name'
# # son.__privatefunc()  # AttributeError: 'AA' object has no attribute '__privatefunc'
# son.func1()

'''
@classmethod
# 类方法：必须通过类的调用，而且此方法的意义：就是对类里面的变量或者方法进行修改添加。
'''
# class A:
#     def __init__(self, name, age):
#         self.name = name
#         self.age = age
#
#     def func(self):
#         print('this is a normal function')
#
#     @classmethod
#     def func2(cls, area, name1):
#         cls.area = area
#         cls.name = name1
#
# obj = A('name1', 32)
# obj.name = 'name2'
# obj.age = 22
# print(obj.__dict__)
#
# obj.func2('area', 'name3')  # A.func2('area', 'name3') 可以实现相同的效果
# print(obj.__dict__)
# print(A.__dict__)

'''
calculate how many times that One class has been sampled
'''
# class C:
#     count = 0
#     def __init__(self):
#         C.cou()
#
#     @classmethod
#     def cou(cls):
#         cls.count += 1
#
# obj = C()
# obj = C()
# obj = C()
# obj = C()
# obj = C()
# print(C.count)

'''
@staticmethod
# 静态方法: 就是一个不依赖类以及对象的一个普通函数，为什么在类里面？
# 为了保证代码的一致性，可调控性，整洁性。
'''

# class D:
#     def __init__(self):
#         print('initiation')
#
#     @staticmethod
#     def static_func(name, age):
#         print(name, age)
#
# obj = D()
# D.static_func('xiaobai', 15)

'''
@property
'''
# class F(object):
#     def __init__(self, name, age):
#         self.name = name
#         self.age = age
#
#     def func(self):
#         print('this is a normal function')
#
#     @property
#     def property_func(self, value):
#         self.name = value
#         print('this is a property')
#
#     @property_func.setter
#     def property_func(self, value):
#         self.name = value
#         print(self.name)
#         print('this is setter')
#
#     @property_func.getter
#     def property_func(self):
#         return 'this is getter'
#
#     @property_func.deleter
#     def property_func(self):
#         print('this is deleter')
#
#
# obj = F('alex', 12)
# obj.property_func = 'test setter'
# print(obj.name)
# print(obj.property_func)
# del obj.property_func

'''
苹果：原始价位8元，折扣价格：0.8
'''
# class Produc:
#     def __init__(self, name, origin_price, discount):
#         self.name = name
#         self.__origin_price = origin_price
#         self.__discount = discount
#
#     @property
#     def Price(self):
#         return self.__origin_price*self.__discount
#
#     @Price.setter
#     def Price(self, new_price):
#         self.__origin_price = new_price
#
# obj = Produc('apple', 20, 0.8)
# print(obj.Price)
# obj.Price = 30
# print(obj.Price)
# print(obj.__dict__)

# class Product:
#
#     def __init__(self, name, origin_price, discount):
#         self.name = name
#         self.__origin_price = origin_price
#         self.__discount = discount
#     @property
#     def price(self):
#         return self.__origin_price * self.__discount
#
#     @price.setter
#     def price(self, new_price):
#         self.__origin_price = new_price
# apple = Product('苹果', 8, 0.95)
# # print(apple.price)
# apple.price = 7
# print(apple.price)

'''
反射！！！！
# 反射：通过 字符串 去操作对象(实例化对象 类, 模块)。
# hasattr() getattr() ***
# setattr() delattr() *
# 对实例化对象的示例
# isinstance(obj, class): whether obj is an object of class or not
# issubclass(class1, class2): whether class1 is a subclass of class2 or not
'''
# class A:
#     pass
#
# class B(A):
#     pass
#
# obj = B()
# print(isinstance(obj, B))
# print(issubclass(A, B))

# class A:
#     name = 'alex'
#     age = 23
#
#     def __init__(self, gender, area):
#         self.gender = gender
#         self.area = area
#
#     def func(self):
#         print(self.gender)
#
# obj = A('male', 'shandong')
# # ret = getattr(obj, 'name')
# ret = getattr(obj, 'func')
# ret()
# # ret1 = hasattr(obj, 'func')
# print(ret1)  # False
# ret2 = setattr(obj, 'height', 1.8)
# # ret3 = delattr(obj, 'func') #AttributeError: func (object has no function attributes)
# # delattr(A, 'func')
# print(ret)
# print(ret1)
# print(obj.__dict__)
# print(A.__dict__)

# 对类

# class A:
#
#     name = 'alex'
#     def __init__(self):
#         pass
#
#     def func(self):
#         print('IN func')
#
# # print(getattr(A, 'name'))
# # ret = getattr(A, 'func')
# # ret(1)
# ret = input('>>>>')  # 'func'
# f1 = getattr(A, ret)(1)

# 对当前模块(文件)
# def func():
#     print('in func')
#
#
# import sys
#
# current_module = sys.modules[__name__]
#
# getattr(current_module, 'func')()
#

# 对其他模块(文件)

# import fs
# print(getattr(fs, 'name'))
# ret = getattr(fs, 'func')
# ret()
#
# # call the function in class in another module
# getattr(fs.test, 'func2')(1) # TypeError: func2() missing 1 required positional argument: 'self'

# import fs
#
# print(getattr(fs,'n1'))
# ret = getattr(fs,'func')
# ret()
#
# # 方法一：
# clas = getattr(fs, 'A')
# print(clas.name)
#
# # 方法二：
# print(getattr(fs.A, 'name'))
# getattr(fs.A, 'func2')(1)

'''
double-underlined function
1, __str__, __len__, 把对象当作字符串进行一系列操作时，对应的反应，必须包含return，且return必须返回对应操作需返回的数据类型；

'''

#
# class A:
#     def __init__(self):
#         self.a=1
#         self.b=2
#         pass
#
#     def __str__(self):
#         print('this is __str__ method')
#         return '__str__ return'
#
#     def __len__(self):
#         print('this is __len__ method')
#         return len(self.__dict__)
#
#     def __hash__(self):
#         return hash(str(self.a))
#
#     def __repr__(self):
#         return 'this is __repr__'
#
#     def __call__(self, *args, **kwargs):
#         return
#
#     def __eq__(self, other):
#         if self.a == other:
#             return True
#         else:
#             return False
#
#     def __del__(self):
#         return 'this is deleting an object'
#
#
# obj = A()
# print(obj)
# print(len(obj))  # TypeError: object of type 'A' has no len()
# print(hash(obj))
# print(repr(obj))
# print('%r' % obj)  # %r, show initial data type
# test_repr = '123'
# print('%r' % test_repr)  # '123'
# print('%s' % test_repr)  # 123
# print(obj == 4)

# class A:
#     def __init__(self):
#         pass
#     def __str__(self):
#         print(666)
#         return '太白'
# a = A()
# # print(a)
# ret = '姓名：%s' % a
# print(ret)

# class A:
#     def __init__(self):
#         pass
#     def __repr__(self):
#         return '太白'
# a = A()
# # print(repr(a))
# print('%r'%a)

# class Foo:
#
#     def __init__(self):
#         pass
#
#     def __call__(self, *args, **kwargs):
#         print(args)
#         print('__call__')
#
# obj = Foo()
# obj('WuSir', 'alex')  # 对象() 触发 __call__()方法

# __new__

# 讨论的 __init__  __new__ 先后顺序
# class A:
#     def __init__(self):
#         self.x = 1
#         print('in init')
#
#     def __new__(cls, *args, **kwargs):
#         print('in __new__')
#         return object.__new__(cls)
#
# obj = A()
# print(obj.x)

# 设计模式：单例模式：让一个类的实例化对象有且只有一个。 ***

# class A:
#     pass
# ret = A()
# ret1 = A()
# print(ret, ret1)

# class A:
#     __instance = None
#     def __new__(cls, *args, **kwargs):
#         if cls.__instance is None:
#             obj = object.__new__(cls)
#             cls.__instance = obj
#         return cls.__instance
#
# ret1 = A()
# ret2 = A()
# ret3 = A()
# print(ret1, ret2, ret3)

# __item__系列 __getitem__  __setitem__ __delitem__ ***
# 对一个对象进行类似于字典的操作，就会触发__item__系列的某个方法。
# class Foo:
#     def __init__(self, name):
#         self.name = name
#
#     # def __getitem__(self, item):
#     #     # print('__getitem__此方法执行了')
#     #     # print(item)
#     #     # return self.item  # self.'name'
#     #     return self.__dict__[item]
#     # def __setitem__(self, key, value):
#     #     self.key = value
#
#     def __delitem__(self, key):
#         print('del obj[key]时,我执行')
#         # self.__dict__.pop(key)
#     # def __delattr__(self, item):
#     #     print('del obj.key时,我执行')
#     #     self.__dict__.pop(item)
#
#
# f = Foo('alex')
# # print(f['name'])
# # f['age'] = 25
# del f['name']
# print(f.__dict__)
'''
serializable modules: pkl, json, shelve
json: 网络传输
1. json.dump(obj, fp)方法接收一个文件句柄，直接将字典转换成json字符串写入文件
2. json.load(fp)方法接收一个文件句柄，直接将文件中的json字符串转换成数据结构返回
'''
# import json

# json.dumps()/json.loads() are for data transmission between different tools,
# eg., python and Java
# dic = {'name': 'alex', 'age': 18, 'gender': 'male'}
# ret = json.dumps(dic, ensure_ascii=False)  # 序列化过程 ： 就是变成一个特殊的字符串
# print(ret)  # json-typed string are characterized with double quotes
# print(dic)  # python-typed string are characterized with single quotes
#
# result = json.loads(ret)  # 反序列化：将序列化的特殊字符串反解成原来的类型。
# print(result)

# dic.dump()/dic.load():
# f = open('json_file', 'w')
# ret = json.dump(dic, f)
# json.dump(): requires two arguments, content that required to be written, and file that required to be written in
# f.close()

# f = open('json_file', 'r')
# print(json.load(f))
# # json.load() : only file to be read is necessary
# f.close()

# exercise 2
# dic2 = {
#     1: {'name': 'alex', 'age': 23, 'gender': 'male'},
#     2: {'name': 'alex', 'age': 23, 'gender': 'female'},
#     3: {'name': 'alex', 'age': 23, 'gender': 'male'},
#     4: {'name': 'alex', 'age': 23, 'gender': 'male'}
# }
# dumps/loads
# ret = json.dumps(dic2, ensure_ascii=False)
# print(ret)
# print(json.loads(ret))

# dump/load
# f1 = open('json_file2', 'w')
# json.dump(dic2, f1)
# f2.close()

# f2 = open('json_file2', 'r')
# print(json.load(f2))
# f2.close()

'''
pkl:只用于Python语言之间的传输，包含所有的python支持的数据类型。
pickle.dump()/pickle.load():写入文件  (这个不仅可以写常规的数据，还可以将对象写入)
'''
import pickle

# dic = {'name': 'xiaobai', 'age': 22, 'gender': 'male'}
# ret = pickle.dumps(dic)
# print(ret)
#
# print(pickle.loads(ret))

# f1 = open('pkl_file', 'wb')  # data in bytes-type was written
# pickle.dump(dic, f1)
# f1.close()
#
# f2 = open('pkl_file', 'rb')  # default mode='r', 'rb' has to be set
# print(pickle.load(f2))

# class A:
#     name = 'xiaobai'
#     def func(self):
#         print(111)
#
# f1 = open('pkl_file2', 'wb')
# pickle.dump(A, f1)
# f1.close()
#
# f2 = open('pkl_file2', 'rb')
# pickle.load(f2).func(1)

'''
random package
'''
# import random

# stupied method
# def select():
#     char_lis = []
#     num_lis =[]
#     for i in range(97, 123):
#         char_lis.append(chr(i))
#     for i in range(0, 10):
#         num_lis.append(i)
#     i = 0
#     code =''
#     while i < 5:
#         i += 1
#         a = random.sample(char_lis)
#         b = random.sample(num_lis)
#         c = random.sample(a, b)
#         code += c
#     return code
# print(select())

# smarter one: create random codes including capitalized and lower-cased characters and numbers
# def code():
#     codes = ''
#     for i in range(1, 6):
#         num = str(random.randint(0, 9))
#         capitalized_char = chr(random.randint(97, 122))
#         lowercased_char = chr(random.randint(65, 90))
#         c1 = random.choice([num, capitalized_char, lowercased_char])
#         codes += c1
#     return codes
#
#
# print(code())
#
# print(random.sample([1, 3, 5, 'a'], 2))  # two arguments required: iterable para, number
# print(random.random())  # return float between 0-1
# print(random.randrange(1, 3))  # randrange: exclude lower bound
# print(random.randint(10, 11))  # randint: include lower bound
# print(random.uniform(0, 10))  # float between upper and lower bounds