Python内置函数dir详解

1.命令介绍

最近学习并使用了一个python的内置函数dir，首先help一下：

>>> help(dir)

Help on built-in function dir in module __builtin__:



dir()

 dir([object]) -> list of strings


 Return an alphabetized list of names comprising (some of) the attributes

 of the given object, and of attributes reachable from it:


 No argument: the names in the current scope.

 Module object: the module attributes.

 Type or class object: its attributes, and recursively the attributes of

 its bases.

 Otherwise: its attributes, its class's attributes, and recursively the

 attributes of its class's base classes.

class A:

 def a(self):

 pass





class A1(A):

 def a1(self):

 pass



if __name__ == '__main__':

 print("dir without arguments:", dir())

 print("dir class A:", dir(A))

 print("dir class A1:", dir(A1))

 a = A1()

 print("dir object a(A1):", dir(a))

 print("dir function a.a:", dir(a.a))

dir without arguments: ['A', 'A1', '__builtins__', '__doc__', '__file__', '__name__', '__package__']

dir class A: ['__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'a']

dir class A1: ['__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'a', 'a1']

dir object a(A1): ['__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'a', 'a1']

dir function a.a: ['__call__', '__class__', '__delattr__', '__doc__', '__eq__', '__format__', '__func__', '__ge__', '__get__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__self__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__']

import A

if __name__ == '__main__':

 print("dir module A:", dir(A))

dir module A: ['A', 'A1', '__builtins__', '__doc__', '__file__', '__name__', '__package__']

4.如何找到当前模块下的类

这是一个烦恼较长时间的一个问题，也没有搜到详细的解决方法，下面是我的集中实现方法。

4.1.方法一：在module下面直接调用

比如在上面的A.py最下面添加一行，即可在后续的代码中可以使用selfDir来查找当前的module下的类，修改后的代码如下：

class A:

 def a(self):

 pass



class A1(A):

 def a1(self):

 pass



curModuleDir=dir() # get dir of current file(module)

if __name__ == '__main__':

 print("dir without arguments:", dir())

 print("dir class A:", dir(A))

 print("dir class A1:", dir(A1))

 a = A1()

 print("dir object a(A1):", dir(a))

 print("dir function a.a:", dir(a.a))

 print("dir current file:", curModuleDir)

4.2.方法二：import当前module
把当前module和别的import一样引用，代码如下：

# A.py

import A as this # import current module



class A:

 def a(self):

 pass



class A1(A):

 def a1(self):

 pass

if __name__ == '__main__':

 print("dir without arguments:", dir())

 print("dir class A:", dir(A))

 print("dir class A1:", dir(A1))

 a = A1()

 print("dir object a(A1):", dir(a))

 print("dir function a.a:", dir(a.a))

 print("dir current file:", dir(this))

import sys

class A:

 def a(self):

 pass
class A1(A):

 def a1(self):

 pass
if __name__ == '__main__':

 print("dir without arguments:", dir())

 print("dir class A:", dir(A))

 print("dir class A1:", dir(A1))

 a = A1()

 print("dir object a(A1):", dir(a))

 print("dir function a.a:", dir(a.a))

 print("dir current file:", dir(sys.modules[__name__])) # 使用__name__获取当前module对象，然后使用对象获得dir

到此这篇关于Python内置函数dir详解就介绍到这了。流过泪的眼睛更明亮，滴过血的心灵更坚强！更多相关Python内置函数dir详解内容请查看相关栏目，小编编辑不易，再次感谢大家的支持！