函数:全部都是显性传参
方法:存在隐性传参
判断方法
通过函数名可大致判断
通过types模块去验证
from types import FunctionType
from types import MethodType
def func():
pass
class A:
def func(self):
pass
@staticmethod
def f():
pass
# print(isinstance(func, FunctionType))
# print(isinstance(func, MethodType))
# 类名调用func 就是一个函数
# print(isinstance(A.func, FunctionType))
# print(isinstance(A.func, MethodType))
# obj = A()
# 对象调用func 就是一个方法
# print(isinstance(obj.func, FunctionType))
# print(isinstance(obj.func, MethodType))
# 对于静态方法的研究
# print(isinstance(A.f, FunctionType))
# print(isinstance(A.f, MethodType))
# obj = A()
# # 对象调用func
# print(isinstance(obj.f, FunctionType))
# print(isinstance(obj.f, MethodType))概念:主要是指程序员可以访问,检测和修改它本身状态或行为的一种能力(自省),
python中面向对象的反射 : 通过字符串的形式操作对象的相关属性,python中的一切事物都是对象(都可以使用反射)
[‘从实例的角度去研究反射‘]
# class A:
#
# static_field = '静态属性'
#
# def __init__(self,name,age):
# self.name = name
# self.age = age
#
# def func(self):
# print('in A func')
# obj = A('MC骚Q',18)
# print(obj.name)
# print(hasattr(obj,'name')) #检查是否有'name'属性
# print(getattr(obj,'name1','没有该属性')) #获取属性,如果没有设置第三个元素,查询不到就会报错
# print(getattr(obj,'name'))
# print(getattr(obj,'name1')) #报错
#
# setattr(obj,'hobby','玩') #增加新的属性
# print(getattr(obj,'hobby'))
#
# delattr(obj,'name') #删除该属性
# print(hasattr(obj,'name'))
# if hasattr(obj,'static_field'):
# print(getattr(obj,'static_field'))
#
# if hasattr(obj,'func'):
# getattr(obj,'func')()#不用实例化,可直接调用方法从类的角度研究反射
# class A:
#
# static_field = '静态属性'
#
# def __init__(self,name,age):
# self.name = name
# self.age = age
#
# def func(self):
# print('in A func')
# obj = A('大表哥',18)
# print(getattr(A,'func'))
# getattr(A,'func')(obj)从脚本的角度研究反射
# import sys
# def func1():
# print('in func1')
# this_modules = sys.modules[__name__] #获取当前脚本这个对象
# print(this_modules)
# print(getattr(this_modules,'func1'))
# getattr(this_modules,'func1')()
# class B:
# static = "B类"
# import sys
# this_modules = sys.modules[__name__]
# cls = getattr(this_modules,"B")
# obj = cls()
# print(obj.static)应用场景
'选择界面'
# class Auth:
#
# def login(self):
# print('登陆函数')
#
# def register(self):
# print('注册函数')
#
# def exit(self):
# print("退出")
#
# while 1:
# function_list = [('login','登录'),('register','注册'),("exit",'退出')]
# for num,option in enumerate(function_list,1):
# print(num,option[1])
# func_name = input("群输入选择:").strip()
# obj = Auth()
# if hasattr(obj,func_name):
# getattr(obj,func_name)()
# else:
# print('输入错误')双下方法是特殊方法,主要供python源码程序员使用
__len__
# class A:
# def __init__(self,name):
# self.name =name
#
# def __len__(self):
# print('触发__len__方法')
# return 10
#
# obj = A('MC')
# ret = len(obj)
# print(ret)__hash__
class A:
def __init__(self):
self.a = 1
self.b = 2
def __hash__(self):
return hash(str(self.a)+str(self.b))
a = A()
print(hash(a))__str__
# class A:
#
# def __init__(self):
# self.name = '太白'
#
# def __str__(self):
# return self.name
#
# obj = A()
# print(obj)
# print(str(obj))__repr__
# class Student:
# def __init__(self,name,age,sex):
# self.name = name
# self.age =age
# self.sex = sex
#
# def __repr__(self):
# return "12"
#
# def __str__(self):
# return f"{self.sex}123"
#
# object = Student(1,2,3)
# object1 = Student(1,2,4)
# object2 = Student(1,2,5)
#
# print(str(object)) #会触发__str__
# print(object)
# print(object1)
# print(object2)
# print(f"此对象为%s" %object) #格式化输出会触发__str__
# print(f"此对象为%r" %object) #格式化输出会触发__repr__
#
# print(obj) #同时存在__str__和__repr__会优先选择__str__执行,优先级别高__call__
# class A:
# def __init__(self):
# self.a =1
# print(111)
#
# def __call__(self, *args, **kwargs):
# print(666)
#
# obj = A()
# obj()__eq__
class A:
def __init__(self):
self.a = 1
self.b = 2
def __eq__(self,obj):
if self.a == obj.a and self.b == obj.b:
return True
a = A()
b = A()
print(a == b)__del__
__new__
# class A(object):
#
# def __init__(self):
# print('in __init__')
#
# def __new__(cls, *args, **kwargs):
# print(cls) #A
# print('in __new__')
# object1 = object.__new__(cls) #2. 其次利用object类的__new__产生一个对象空间
# return object # #3. 将这个对象空间返回给了A()即obj
#
# obj = A()#1. 先触发__new__,将类名自动传给cls__item__
class Foo:
def __init__(self,name):
self.name=name
def __getitem__(self, item):
print(self.__dict__[item])
def __setitem__(self, key, value):
self.__dict__[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)
f1=Foo('sb')
f1['age']=18
f1['age1']=19
del f1.age1
del f1['age']
f1['name']='alex'
print(f1.__dict__)上下文管理器相关__enter__和__exit__
# 如果想要对一个类的对象进行with as 的操作 不行。
class A:
def __init__(self, text):
self.text = text
with A('大爷') as f1:
print(f1.text)class A:
def __init__(self, text):
self.text = text
def __enter__(self): # 开启上下文管理器对象时触发此方法
self.text = self.text + '您来啦'
return self # 将实例化的对象返回f1
def __exit__(self, exc_type, exc_val, exc_tb): # 执行完上下文管理器对象f1时触发此方法
self.text = self.text + '这就走啦'
with A('大爷') as f1:
print(f1.text)
print(f1.text)自定义上下文管理器
class Diycontextor:
def __init__(self,name,mode):
self.name = name
self.mode = mode
def __enter__(self):
print "Hi enter here!!"
self.filehander = open(self.name,self.mode)
return self.filehander
def __exit__(self,*para):
print "Hi exit here"
self.filehander.close()
with Diycontextor('py_ana.py','r') as f:
for i in f:
print i原文：https://www.cnblogs.com/W-Y-C/p/11178071.html