函数自省

Posted 2021-02-04 frank-shen

函数自省: 函数可以通过__dir__查看函数具有哪些属性 

__closure__函数闭包，即自由变量的绑定

__globals__ 函数所在模块中的全局变量

__defaults__ 形参的默认值

__kwdefaults__ only-positional 的默认值

__annotations__ 参数和返回值的注解 

__name__ 函数名称 

__qualname__ 函数的限定名称 

__code__ 编译成字节码的函数元数据和函数定义体

__call__ 可调用对象协议

a = 0


def func(b=1, *, d=5) -> object:
    global a
    c = 0
    def inner():
        nonlocal c
        c += 1
        print(c)
    return inner


print(dir(func))
print(func.__annotations__)  # 参数和返回值的注解
print(func.__name__)          # 函数名
print(func.__qualname__)      # python 3.3后加入 通过类和函数的如何定义的 来确定他们的限定名称
print(func.__call__)          # 可调用对象协议
print(func.__code__)          # code对象引用
print(func.__code__.co_varnames)      # 局部变量
print(func.__code__.co_argcount)      # 位置参数个数
print(func.__defaults__)      # 参数的默认值
print(func.__kwdefaults__)    # 仅限关键字参数的默认值
print(func.__globals__)       # 全局变量   函数返回一个全局变量的字典，包括所有导入的变量
g = func()
print(g.__closure__)         # 函数闭包 即自由变量的绑定
print(g.__code__.co_freevars)         # 自由变量

[‘__annotations__‘, ‘__call__‘, ‘__class__‘, ‘__closure__‘, ‘__code__‘, ‘__defaults__‘, ‘__delattr__‘, ‘__dict__‘, ‘__dir__‘, ‘__doc__‘, ‘__eq__‘, ‘__format__‘, ‘__ge__‘, ‘__get__‘, ‘__getattribute__‘, ‘__globals__‘, ‘__gt__‘, ‘__hash__‘, ‘__init__‘, ‘__init_subclass__‘, ‘__kwdefaults__‘, ‘__le__‘, ‘__lt__‘, ‘__module__‘, ‘__name__‘, ‘__ne__‘, ‘__new__‘, ‘__qualname__‘, ‘__reduce__‘, ‘__reduce_ex__‘, ‘__repr__‘, ‘__setattr__‘, ‘__sizeof__‘, ‘__str__‘, ‘__subclasshook__‘]
{‘return‘: <class ‘object‘>}
func
func
<method-wrapper ‘__call__‘ of function object at 0x0000023B52E966A8>
<code object func at 0x0000023B52E7A150, file "D:/workspace/Python/练习/test.py", line 715>
(‘b‘, ‘d‘, ‘inner‘)
1
(1,)
{‘d‘: 5}
{‘__name__‘: ‘__main__‘, ‘__doc__‘: None, ‘__package__‘: None, ‘__loader__‘: <_frozen_importlib_external.SourceFileLoader object at 0x0000023B52C2B4A8>, ‘__spec__‘: None, ‘__annotations__‘: {}, ‘__builtins__‘: <module ‘builtins‘ (built-in)>, ‘__file__‘: ‘D:/workspace/Python/练习/test.py‘, ‘__cached__‘: None, ‘__author__‘: ‘Frank Shen‘, ‘a‘: 0, ‘requests‘: <module ‘requests‘ from ‘D:\anaconda\lib\site-packages\requests\__init__.py‘>, ‘choice‘: <bound method Random.choice of <random.Random object at 0x0000023B5315E138>>, ‘func‘: <function func at 0x0000023B52E966A8>}
<method-wrapper ‘__get__‘ of function object at 0x0000023B52E966A8>
(<cell at 0x0000023B53F587F8: int object at 0x000000005D116C20>,)
(‘c‘,)