The function dir () in Python

In Python, the dir () function returns a list of valid properties of the object. Quantrimang will learn more about this function content through the article. Invites you to read the track.

The dir () function syntax in Python

 dir([object]) 

Parameters of function dir ()

Dir () only returns results for one object.

object: object that gets dir () returns a list of attributes, optional parameters.

Return value from dir ()

Dir () will return a list of valid attributes of the object.

If the object has __dir __ () function, when calling dir will return all the properties.

If the object does not have __dir __ () then the function will try to find through __dict __ () (if any). In this case, the list of properties returned from dir () may be incomplete.

If you don't pass the object to dir () , it will return the property within the current local scope.

Example 1: How does the dir () function work?

 number = [1, 2, 3] 
 print(dir(number)) 
  
 print('nGia tri tra ve tu dir() khong truyen object') 
 print(dir()) 

Run the program, the result is:

 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__dir__', '__doc__', 
 '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', 
 '__iadd__', '__imul__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', 
 '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', 
 '__rmul__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'append', 
 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort'] 
 
 Gia tri tra ve tu dir() khong truyen object 
 ['__annotations__', '__builtins__', '__doc__', '__file__', '__loader__', '__name__', '__package__', 
 '__spec__', 'number'] 

Example 2: dir () with user defined object

 class Person: 
 def __dir__(self): 
 return ['age', 'name', 'salary'] 
 
 teacher = Person() 
 print(dir(teacher)) 

Run the program, the result is:

 ['age', 'name', 'salary'] 

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