一些相關BIF

issubclass(class, classing)

用來判斷類引數class是否是型別引數classinfo的子類

>>> class A:
        pass 
>>> class B(A):
        pass
>>> issubclass(B, A)
True
>>> issubclass(B, B)
True
>>> is subclass(B, object)
True
>>> class C:
        pass
>>> 
 
issubclass(B, C)
False

isinstance(object, classinfo)

判斷 object 是否為 classinfo 的實體
1. 如果第一個引數不是物件，則永遠返回False
2. 如果第二個引數不是類或者由類物件組成的元祖，
會丟擲一個TypeError異常

>>> b1 = B()
>>> isinstance(b1, B)
True
>>> isinstance(b1, A)
True
>>> isinstance(b1, C)
False
>>> 
 
isinstance(b1, (A,B,C))
True

hasattr(object, name)

判斷 name 是否為 object 的屬性名稱
attire = attribute:屬性

>>> class C:
        def __init__(self, x=0):
            self.x = x
>>> c1 = C()
>>> hasattr(c1, 'x')
True

getattr(object, name[, default])

如果存在name屬性（方法）則返回name的值（方法地址）否則返回default值。

>>> getattr(c1, 'x')
0
>>> getattr(c1, 'y')
Traceback (most recent call last):
......
AttributeError: 'C' object has no attribute 'y'
>>> getattr(c1, 'y', '您所訪問的屬性不存在...')
'您所訪問的屬性不存在...'

setattr(object, name, value)

設定物件 object 的新屬性

>>> setattr(c1, 'y', 'kuangren')
>>> getattr(c1, 'y', '您所訪問的屬性不存在...')
'kuangren'

delattr(object, name)

該函式刪除該obj的一個由string指定的屬性

>>> delattr(c1, 'y')
>>> delattr(c1, 'y')
Traceback (most recent call last):
  File '<pyshell#31>', line 1, in <module>
    delattr(c1, 'y')
AttributeError: y

property(fget=None, fset=None, fdel=None, doc=None)

>>> class C:
        def __init__(self, size=10):
            self.size = size
        def getSize(self):
            return self.size
        def setSize(self, value):
            self.size = value
        def delSize(self):
            del self.size
        x = property(getSize, setSize, delSize)

>>> c1 = C()
>>> c1.getSize()
10
>>> c1.x
10
>>> c1.x = 18
>>> c1.x
18
>>> c1.getsize()
18
>>> del c1.x
>>> c1.size
Traceback (most recent call last):
...
AttributeError: 'C' object has no attribute 'size'