As Python stores their instance variables in the form of dictionary belonging to the respective object both dir() and vars() functions are used to list the attributes of an instance/object of the Python class. Though having a similar utility these functions have significant individual use cases.
dir() Function:
This function displays more attributes than vars() function, as it is not limited to an instance. It displays the class attributes as well. It also displays the attributes of its ancestor classes.
vars() Function:
This function displays the attribute of an instance in the form of a dictionary.
The below table provides with some significant difference between var() and dir():
| vars() | dir() |
|---|---|
| Returns a dictionary of objects of single class where used | Returns a dictionary of objects of single class where used and its base classes |
| It returns a dictionary corresponding to the current local symbol table when no argument is passed | It returns the list of names in the current local scope when passed no argument |
| It returns a dictionary corresponding to the object’s symbol table if a module, class or class instance object as argument (or anything else that has a __dict__ attribute) is passed. | It attempt to return a list of valid attributes for that object when passed an argument |
| As instances builtin types do not have __dict__ attribute, it returns an Error when used in a built-in type instance. | It can be used with all built-in types without error |
Example 1:
Python3
vars(list).keys() |
Output:
Example 2:
Python3
dir(list) |
Output:
