见stackoverflow上有关python的callable的讨论http://stackoverflow.com/questions/111234/what-is-a-callable-in-python

python的Object是一个泛型概念，而不是特制类的对象，比如函数也可以是一个Object，类也可以是Object。你看下callable()的原型，定义在builtin.py中

def callable(p_object): # real signature unknown; restored from __doc__ """ callable(object) -> bool Return whether the object is callable (i.e., some kind of function). Note that classes are callable, as are instances with a __call__() method. """ return False

仔细一看，这是英语断句的问题啊

englishPython has [a more general concept] of [[callable object], that is every [object that can be called, which means applied on some data]]

不是“每个对象都能被调用”，而是“callable object”是“所有能被调用的对象”，最后那个从句解释调用的概念是“被应用于数据”。

Python has a concept

Python has a more general concept

Python has a more general concept of callable object

Python has a more general concept of callable object, that is every object that can be called

Python has a more general concept of callable object, that is every object that can be called, which means applied on some data

同意 @charliecui 说的python的Object是一个泛型概念。

对于文中的话，我理解是python中一切都是对象，这些对象都是object的实例，Python创建对象是通过type方式，这个type又有一个__call__方法，实现了这个方法，最终的对象就能被调用（callable）。

大概意思就是这些对象通过技巧都是可以调用的，通过使这些对象可以调用来处理一些数据。

简单的用法就是类似web框架中的路由 (Router), 使得 Router直接装饰，不需要额外的创建实例来创建对象，而是让自身就是一个可以调用的对象。

python
class Router(): def __call__(self): pass @Router('/index') def index(): pass

具体实现可以参考 可以参考 https://github.com/nod/tornroutes/blob/master/tornroutes/__init__.py

一个给tornado实现router的decorator