“上周简单地学习了Python的基础语法和API，整理一下加深理解和印象”
Python中的反射
Pyhthon可查类型、可反射。
反射的方式有：
1.type()查类型；
a = str("sssss")
print(type([]) )
print(type({}))
print(type(''))
print(type(0.0))
2.isinstance()查引用；
class Plant:
life = 0
pass
class Tree(Plant): pass # Dummy class derived from Plant
tree = Tree() # A new instance of Tree class
print("isinstance")
print (isinstance(tree, Tree)) # True
print (isinstance(tree, Plant)) # True
print (isinstance(tree, object) ) # True
print (type(tree) is Tree) # False
print (type(tree).__name__ == "instance") # True
print (tree.__class__.__name__ == "Tree") # True
3.issubclass()查继承；
print("isubclass")
print (issubclass(Tree, Plant)) # True
print (issubclass(Tree, object)) # False in Python 2
print (issubclass(int, object)) # True
#print (issubclass(tree, Plant)) # Error - tree is not a class
4.callable()是否可调用；
print("callable")
print(callable([1,2].pop))
print(callable([1,2].pop()))
5.dir()查包含的属性名；
print("Dir")
print(dir(3))
print(dir("HelloWorld"))
print(dir([1,2]))
print(dir(re))
- getattr() 第一个参数是对象实例obj,name是个字符串，是对象的成员函数名字或者成员变量，default当对象没有这个属相的时候就返回默认值，如果没有提供默认值就返回异常。
print("attribute")
print(getattr(tree, "life"))
#print(getattr(tree, "life?")) 没有就会报错
print(getattr(tree, "life?", None))
