双下方法,源码相关,异常处理

#!/usr/bin/env python
# -*- coding:utf-8 -*-

# 1.列举你了解的面向对象中的特殊成员，并为每个写代码示例。
'''
__init__初始化:
class A:
    def __init__(self, name):
        self.name = name

__new__创建空对象:
class B:
    def __new__(cls, *args, **kwargs):
        return object.__new__(cls)

__ call__调用:
class C:
    def __call__(self, *args, **kwargs):
        print('执行call方法')

__ getitem__   __ setitem__   __ delitem__:
class D:
    def __setitem__(self, key, value):
        pass
    def __getitem__(self, item):
        return item+'xxx'
    def __delitem__(self, key):
        pass

__str__ return什么输出什么:
class E:
    def __str__(self):
        return 123

__dict__ 对象中找到所有变量并将其转换为字典:
class F:
    def __init__(self, name):
        self.name = name

上下文管理:
class Foo(object):
    def __enter__(self):
        self.x = open('a.txt',mode='a',encoding='utf-8')
        return self.x
    def __exit__(self, exc_type, exc_val, exc_tb):
        self.x.close()

两个对象相加:
class G(object):
    def __add__(self, other):
        return 123

obj1 = G()
obj2 = G()
val = obj1 + obj2
print(val)
'''

# 2.看代码写结果
'''
class Foo(object):

    def __init__(self, age):
        self.age = age

    def display(self):
        print(self.age)

data_list = [Foo(8), Foo(9)]
for item in data_list:
    print(item.age, item.display())
# 8    8 None    9    9 None
'''

# 3.看代码写结果
'''
class Base(object):
    def __init__(self, a1):
        self.a1 = a1

    def f2(self, arg):
        print(self.a1, arg)

class Foo(Base):
    def f2(self, arg):
        print('666')

obj_list = [Base(1), Foo(2), Foo(3)]
for obj in obj_list:
    obj.f2(4)
# 1 4    666    666
'''

# 4.看代码写结果
'''
class StarkConfig(object):

    def __init__(self, num):
        self.num = num

    def changelist(self, request):
        print(self.num, request)

class RoleConfig(StarkConfig):

    def changelist(self, request):
        print('666')

config_obj_list = [StarkConfig(1), StarkConfig(2), RoleConfig(3)]
for item in config_obj_list:
    print(item.num)
# 1    2    3
'''

# 5.看代码写结果
'''
class StarkConfig(object):

    def __init__(self, num):
        self.num = num

    def changelist(self, request):
        print(self.num, request)

class RoleConfig(StarkConfig):
    pass

config_obj_list = [StarkConfig(1), StarkConfig(2), RoleConfig(3)]
for item in config_obj_list:
    item.changelist(168)
# 1 168    2 168    3 168
'''

# 6.看代码写结果
'''
class StarkConfig(object):

    def __init__(self, num):
        self.num = num

    def changelist(self, request):
        print(self.num, request)

class RoleConfig(StarkConfig):

    def changelist(self, request):
        print(666, self.num)

config_obj_list = [StarkConfig(1), StarkConfig(2), RoleConfig(3)]
for item in config_obj_list:
    item.changelist(168)
# 1 168    2 168    666 3
'''

# 7.看代码写结果
'''
class StarkConfig(object):

    def __init__(self, num):
        self.num = num

    def changelist(self, request):
        print(self.num, request)

    def run(self):
        self.changelist(999)

class RoleConfig(StarkConfig):

    def changelist(self, request):
        print(666, self.num)

config_obj_list = [StarkConfig(1), StarkConfig(2), RoleConfig(3)]
config_obj_list[1].run()
config_obj_list[2].run()
# 2 999    666 3
'''

# 8.看代码写结果
'''
class StarkConfig(object):
    def __init__(self, num):
        self.num = num

    def changelist(self, request):
        print(self.num, request)

    def run(self):
        self.changelist(999)


class RoleConfig(StarkConfig):
    def changelist(self, request):
        print(666, self.num)


class AdminSite(object):
    def __init__(self):
        self._registry = {}

    def register(self, k, v):
        self._registry[k] = v


site = AdminSite()
print(len(site._registry))  # 0
site.register('range', 666)
site.register('shilei', 438)
print(len(site._registry))  # 2
site.register('lyd', StarkConfig(19))
site.register('yjl', StarkConfig(20))
site.register('fgz', RoleConfig(33))
print(len(site._registry))  # 5
print(site._registry)  # {'range':666,'shilei':438,'lyd':地址,'yjl':地址,'fgz':地址}
'''

# 9.看代码写结果
'''
class StarkConfig(object):
    def __init__(self, num):
        self.num = num

    def changelist(self, request):
        print(self.num, request)

    def run(self):
        self.changelist(999)


class RoleConfig(StarkConfig):
    def changelist(self, request):
        print(666, self.num)


class AdminSite(object):
    def __init__(self):
        self._registry = {}

    def register(self, k, v):
        self._registry[k] = v


site = AdminSite()
site.register('lyd', StarkConfig(19))
site.register('yjl', StarkConfig(20))
site.register('fgz', RoleConfig(33))
print(len(site._registry))  # 3
for k, row in site._registry.items():
    row.changelist(5)
# 19 5    20 5    666 33
'''

# 10.看代码写结果
'''
class StarkConfig(object):
    def __init__(self, num):
        self.num = num

    def changelist(self, request):
        print(self.num, request)

    def run(self):
        self.changelist(999)


class RoleConfig(StarkConfig):
    def changelist(self, request):
        print(666, self.num)


class AdminSite(object):
    def __init__(self):
        self._registry = {}

    def register(self, k, v):
        self._registry[k] = v


site = AdminSite()
site.register('lyd', StarkConfig(19))
site.register('yjl', StarkConfig(20))
site.register('fgz', RoleConfig(33))
print(len(site._registry))  # 3
for k, row in site._registry.items():
    row.run()
# 19 999    20 999    666 33
'''

# 11.看代码写结果
'''
class UserInfo(object):
    pass


class Department(object):
    pass


class StarkConfig(object):
    def __init__(self, num):
        self.num = num

    def changelist(self, request):
        print(self.num, request)

    def run(self):
        self.changelist(999)


class RoleConfig(StarkConfig):
    def changelist(self, request):
        print(666, self.num)


class AdminSite(object):
    def __init__(self):
        self._registry = {}

    def register(self, k, v):
        self._registry[k] = v(k)


site = AdminSite()
site.register(UserInfo, StarkConfig)
site.register(Department, StarkConfig)
print(len(site._registry))  # 2
for k, row in site._registry.items():
    row.run()
# userinfo名称 999    department 999
'''

# 12.看代码写结果
'''
class F3(object):
    def f1(self):
        ret = super().f1()
        print(ret)
        return 123

class F2(object):
    def f1(self):
        print('123')

class F1(F3, F2):
    pass

obj = F1()
obj.f1()
# 123    None
'''

# 13.看代码写结果
'''
class Base(object):
    def __init__(self, name):
        self.name = name

class Foo(Base):
    def __init__(self, name):
        super().__init__(name)
        self.name = "于大爷"

obj1 = Foo(1)
print(obj1.name)    # 于大爷

obj2 = Base(1)
print(obj2.name)    # 1
'''

# 14.看代码写结果
'''
class Base(object):
    pass

class Foo(Base):
    pass

obj = Foo()
print(type(obj) == Foo)         # True
print(type(obj) == Base)        # False
print(isinstance(obj, Foo))     # True
print(isinstance(obj, Base))    # True
'''

# 15.看代码写结果
'''
class StarkConfig(object):
    def __init__(self, num):
        self.num = num
    def __call__(self, *args, **kwargs):
        print(self.num)
class RoleConfig(StarkConfig):
    def __call__(self, *args, **kwargs):
        print(self.num)

v1 = StarkConfig(1)
v2 = RoleConfig(11)

v1()    # 1
v2()    # 11
'''

# 16.看代码写结果
'''
class StarkConfig(object):
    def __init__(self, num):
        self.num = num
    def run(self):
        self()
    def __call__(self, *args, **kwargs):
        print(self.num)
class RoleConfig(StarkConfig):
    def __call__(self, *args, **kwargs):
        print(345)
    def __getitem__(self, item):
        return self.num[item]
v1 = RoleConfig('alex')
v2 = StarkConfig("wupeiqi")
print(v1[1])    # l
print(v2())     # wupeiqi None
'''

# 17.补全代码
'''
class Context:
    def __enter__(self):
        print('开始')
        return self

    def do_something(self):
        print('进行中')

    def __exit__(self, exc_type, exc_val, exc_tb):
        print('退出')

with Context() as ctx:
    ctx.do_something()
'''

# 18.补全代码
'''
class Stack(object):
    def __init__(self):
        self.data_list = []

    def push(self, val):
        self.data_list.append(val)

    def pop(self):
        self.data_list.pop(-1)


obj = Stack()
# 调用push方法，将数据加入到data_list中。
obj.push('alex')
obj.push('武沛齐')
obj.push('金老板')
# 调用pop讲数据从data_list获取并删掉，注意顺序(按照后进先出的格式)
v1 = obj.pop()  # 金老板
v2 = obj.pop()  # 武沛齐
v3 = obj.pop()  # alex
# 请补全Stack类中的push和pop方法，将obj的对象维护成 后进先出 的结构。
'''

# 19.如何主动触发一个异常？
'''
raise Exception()
'''


# 20.看代码写结果
'''
def func(arg):
    try:
        int(arg)
    except Exception as e:
        print('异常')
    finally:
        print('哦')


func('123')       # 哦
func('二货')      # 异常  哦
'''