Python面向对象之内置函数相关知识总结

def func():
    pass
 
print( callable(func) ) # True

class Foo(object):
    pass
 
print( callable(Foo) ) # True

class Foo(object):
	pass
 
obj = Foo()
print( callable(obj) ) # False

class Foo(object):
 
    def __call__(self, *args, **kwargs):
        pass
    
obj = Foo()
print( callable(obj) ) # True

def do_something(handler):
    handler()

class Top(object):
    def message(self, num):
        print("Top.message", num)
        
class Base(Top):
    pass
 
class Foo(Base):
 
    def message(self, num):
        print("Foo.message", num)
        super().message(num + 100)
 
 
obj = Foo()
obj.message(1)
 
>>> Foo.message 1
>>> Top.message 101

class Base(object):
 
    def message(self, num):
        print("Base.message", num)
        super().message(1000)
 
 
class Bar(object):
 
    def message(self, num):
        print("Bar.message", num)
 
 
class Foo(Base, Bar):
    pass
 
 
obj = Foo()
obj.message(1)
 
>>> Base.message 1
>>> Bar.message 1000

info = dict() # {}
info['name'] = "华青水上"
info["age"] = 18
 
value = info.get("age")
 
print(value)

class MyDict(dict):
 
    def get(self, k):
        print("自定义功能")
        return super().get(k)
 
 
info = MyDict()
info['name'] = "华青水上" # __setitem__
info["age"] = 18       # __setitem__
print(info)
 
value = info.get("age")
 
print(value)

v1 = "华青水上"
result = type(v1)
print(result) # <class 'str'>

v2 = "华青水上"
print( type(v2) == str )  # True
 
v3 = [11, 22, 33] # list(...)
print( type(v3) == list )  # True

class Foo(object):
    pass
 
v4 = Foo()
 
print( type(v4) == Foo )  # True

class Top(object):
    pass
 
 
class Base(Top):
    pass
 
 
class Foo(Base):
    pass
 
 
v1 = Foo()
 
print( isinstance(v1, Foo) )   # True，对象v1是Foo类的实例
print( isinstance(v1, Base) )  # True，对象v1的Base子类的实例。
print( isinstance(v1, Top) )   # True，对象v1的Top子类的实例。

class Animal(object):
    def run(self):
        pass
 
class Dog(Animal):
    pass
 
class Cat(Animal):
    pass
 
data_list = [
    "alex",
    Dog(),
    Cat(),
	"root"
]
 
for item in data_list:
    if type(item) == Cat:
        item.run()
    elif type(item) == Dog:
        item.run()
    else:
        pass
    
for item in data_list:
    if isinstance(item, Animal):
        item.run()
    else:
        pass

class Top(object):
    pass
 
 
class Base(Top):
    pass
 
 
class Foo(Base):
    pass
 
 
print(issubclass(Foo, Base))  # True
print(issubclass(Foo, Top))   # True